Rule changes for F4 [Archive] - Kiwi Biker forums

Skunk

9th April 2011, 11:50

We at the Vic Club had a member propose a rule change for F4 100cc two strokes. It was submitted to MNZ in October 2010 and (even though we have followed it up) we haven't heard anything. :mellow:

So: I'm proposing two 'unofficial' rule changes:

1. F4 100cc two stoke to be a maximum of 107cc (to allow the use of KT100 pistons in MB100 engines - cheaper to get than quality MB100 pistons)
2a. Maximum effective carb size for 125cc two stroke to be 30mm or
2b. Maximum effective carb size for 125cc two stroke to be 28mm

Vote now if you are an MNZ member - quote your licence number and I'll tally up the results. Voting closes 1 June 2011.

Vote for or against on each proposal. I plan to see if we can't 'even' the playing field for 125's and keep the running costs of MB100's down.

Disclaimer: I have a TF125 (std except for the chamber).

RDjase

9th April 2011, 13:02

We at the Vic Club had a member propose a rule change for F4 100cc two strokes. It was submitted to MNZ in October 2010 and (even though we have followed it up) we haven't heard anything. :mellow:

So: I'm proposing two 'unofficial' rule changes:

1. F4 100cc two stoke to be a maximum of 107cc (to allow the use of KT100 pistons in MB100 engines - cheaper to get than quality MB100 pistons)
2a. Maximum effective carb size for 125cc two stroke to be 30mm or
2b. Maximum effective carb size for 125cc two stroke to be 28mm

Vote now if you are an MNZ member - quote your licence number and I'll tally up the results. Voting closes 1 June 2011.

Vote for or against on each proposal. I plan to see if we can't 'even' the playing field for 125's and keep the running costs of MB100's down.

Disclaimer: I have a TF125 (std except for the chamber).

Great ideas !

Rule 1, Yes
Rule 2a, Yes

Rule 3? , water cooled 125 2 Stroke

MNZ# 19813

Ivan

9th April 2011, 13:46

I think it should be fair considering we can now use 150 cbrs etc so

both i tick yes to

Ivan Juggins 13660

saxet

9th April 2011, 14:44

Sorry- don't agree.

Rule 1 doesn't help anyone except those using MB100 motors- what about other engines.

Rule 2 the 24 mm carb isn't a hinderence to gaining power, same with no water cooling.

As far asI can see the 2 strokes have an advantge when tuned well.

MNZ 8522

Trudes

9th April 2011, 15:21

1. For
2a. For

19887

Slingshot

9th April 2011, 16:07

Increasing the carb size for 125 smokers would suck for 100cc smokers.

jasonu

9th April 2011, 17:31

TZ350 and one or two others have proved good HP (near 30 rwhp) can be made from aircooled 125 2T motors with the presant 24mm carb rule. IMO that particular rule is OK and doesn't need to be changed.
If you make it easier for the AC 125's then the 100's will want something, then the 4t 150's will want something then...

speedpro

9th April 2011, 17:42

1. F4 100cc two stoke to be a maximum of 107cc (to allow the use of KT100 pistons in MB100 engines - cheaper to get than quality MB100 pistons)
2a. Maximum effective carb size for 125cc two stroke to be 30mm or
2b. Maximum effective carb size for 125cc two stroke to be 28mm

1. definite NO, it would make getting 30ish hp from an MB not too hard - unfair
2a. no point, 24mm carb is not actually a restriction, see ESE
2b. no point, 24mm carb is not actually a restriction, see ESE

Wobbly has said a number of times that the 24mm carb rule doesn't restrict the performance of a well built 125.

Proposed change 1 would help with costs but would also allow mega revs and horsepower. MB motors I have built have done over 5 years with lots of racing on the same piston. If you look at the cost of a piston spread over 4-6 years racing it isn't much. If you are going through pistons then you need to find out why rather than finding a cheaper piston.

MNZ4597

Dom

9th April 2011, 20:16

Current rules are fine. A well built 2 stroke in a 125GP chassis will definitely smoke any 4 stroke offering. It might look like the CBR/FXR have the upper hand but it's because recently national champion/lap record holders like Al Hoogie ('10 125GP champ), Kenneth Jones (Levels 125GP lap record) are riding them.

k14

9th April 2011, 20:23

1. definite NO, it would make getting 30ish hp from an MB not too hard - unfair
2a. no point, 24mm carb is not actually a restriction, see ESE
2b. no point, 24mm carb is not actually a restriction, see ESE

Wobbly has said a number of times that the 24mm carb rule doesn't restrict the performance of a well built 125.

Proposed change 1 would help with costs but would also allow mega revs and horsepower. MB motors I have built have done over 5 years with lots of racing on the same piston. If you look at the cost of a piston spread over 4-6 years racing it isn't much. If you are going through pistons then you need to find out why rather than finding a cheaper piston.

MNZ4597
Agreed, nothing is broken so nothing needs to be changed. Leave the rules alone.

MNZ 15930

Bert

9th April 2011, 20:33

1. definite NO, it would make getting 30ish hp from an MB not too hard - unfair
2a. no point, 24mm carb is not actually a restriction, see ESE
2b. no point, 24mm carb is not actually a restriction, see ESE

... If you are going through pistons then you need to find out why rather than finding a cheaper piston.

MNZ4597

Agreed, nothing is broken so nothing needs to be changed. Leave the rules alone.

MNZ 15930

I don't really see the benefit on changing rule 1.; we are already allowed to run them within the current rules (but you need to do some work first).

2&3. well maybe at a club level for newbies??? but no way at national/gp level. otherwise we should just park up the 100cc 2T (which would make me cry).

MNZ 975 (last time I looked)

Kickaha

9th April 2011, 20:40

Agreed, nothing is broken so nothing needs to be changed. Leave the rules alone.

MNZ 15930

What the old retired guy said +1

MNZ10818

Yow Ling

9th April 2011, 21:03

leave it alone, not very well thought out

mnz16666

all4A50s

9th April 2011, 22:09

Yes to 1. yes to 2b. no to 2a.

Buddha#81

10th April 2011, 08:54

against all proposed changes......not broken no fix needed.

Brent Cotton
14116

RDjase

10th April 2011, 08:56

A well built 2 stroke in a 125GP chassis will definitely smoke any 4 stroke offering

How many 125GP rolling frames are for sale and how much do they sell for?

kel

10th April 2011, 10:25

If change is required then Aussie buckets Motolite gets my vote! XR200's and motorcrosser 80's :done:

jasonu

10th April 2011, 14:36

If change is required then Aussie buckets Motolite gets my vote! XR200's and motorcrosser 80's :done:

That won't be 'Buckets' anymore.

gatch

10th April 2011, 16:38

Negative to all three.

Daniel Gatchell.
MNZ # 22752.

Buckets4Me

10th April 2011, 20:18

I dont want to rock the boat so will wait and see what MNZ come back with

and team E.S.E might just have to start looking for 40 h/p if the rulez do change :facepalm:

kel

10th April 2011, 20:37

That won't be 'Buckets' anymore.

Sure it will, Aussie buckets.
Imagine it, a fully worked XR200 in an RS125 chassis, you have to admit that would be fun, plus there would be spares and performance parts to keep the things going for years to come. The time of buckets actually being built out of buckets and bits/bobs, what ever it was, has passed. Lets embrace the future and as my man John would say close the gap with Australia!

Kickaha

10th April 2011, 20:41

close the gap with Australia!

Why bother when the current formula works well and we don't have trans Tasman competition

The thread was about voting and discussion on some proposed rule changes to do with some stinky two strokes not fucking a class entirely with some unneeded four stroke rules

koba

10th April 2011, 20:47

Leave the rules alone.

Malcolm Nabbs.
19020.

(I have an MB100 and still think the rules are fine.)

kel

10th April 2011, 20:53

The thread was about voting and discussion on some proposed rule changes to do with some stinky two strokes not fucking a class entirely with some unneeded four stroke rules

Obviously an FXR owner:zzzz:

Kickaha

10th April 2011, 21:05

Obviously an FXR owner:zzzz:

Wash your mouth out with battery acid, I wouldn't own one of those unless you paid me, I am quite happy to ride and crash other peoples though

bucketracer

10th April 2011, 22:58

.......The time of buckets actually being built out of buckets and bits/bobs, what ever it was, has passed........

Not so, check the ESE thread......

Skunk

11th April 2011, 01:05

Oh well. Looking at the voting I guess I'll forget this then.

I need deeper pockets (ok, I need pockets) and to modify the 125 just to stay level with a stock FXR. RS125 chassis are so far out of reach they may as well not exist. The idea was to level the START point of the engines - not the END point. That's for the deep pockets and idle hands to do.

I don't understand the thinking behind several posts. I feel people are looking at how it will affect them rather than the class.

Lesson learnt.

jasonu

11th April 2011, 04:36

Oh well. Looking at the voting I guess I'll forget this then.

I need deeper pockets (ok, I need pockets) and to modify the 125 just to stay level with a stock FXR. RS125 chassis are so far out of reach they may as well not exist. The idea was to level the START point of the engines - not the END point. That's for the deep pockets and idle hands to do.

I don't understand the thinking behind several posts. I feel people are looking at how it will affect them rather than the class.

Lesson learnt.

Not necessarily deep pockets.
You can gain a lot for not much $'s with some careful porting. Old RS pipes are cheap enough and when modded (free if you do it yaself) can yield nice gains. Unbolting unnecessary parts to loose weight is more or less free. Drilling holes (in the right places of course) is free. Scrounge around the wreckers, TM and the pits might get you a bargain priced carb or ignition for example. Suspension mods like altering the front damper rods is free and, in my experience, will help handeling and lap times. Buy A. Graham Bells book 2 Stroke Tuners Guide for $30-$40 is a really good move. There is a wealth of free information on KB such as in ESE's mega thread.
However, by far the easiest and cheapest way to have a fast bike is to buy an already proven, already built bike.

Buckets4Me

11th April 2011, 06:49

I need deeper pockets (ok, I need pockets)

and to modify the 125 just to stay level with a stock FXR.

start with the right bike then

my gp125 with only slight mods worked fine for years :woohoo:
3rd in the 2 hour (infrount of fxr's)

all it neaded was a decent rider

it was built up with an rs125 chassie later for under $2000 (about what an fxr would cost)

I dont think you have learnt any lessons YET!!

if you cant beat an FXR buy one (if you have the money):sick:

if you want a 2 smoker

START WITH A GOOD ONE not some $100 shit bucket (show me an fxr that costs $100 and is running)

rant over SPEND SOME MONEY (it dosent have to be much. snow boarding costs more):facepalm:

koba

11th April 2011, 07:25

\
I don't understand the thinking behind several posts. I feel people are looking at how it will affect them rather than the class.

Lesson learnt.

I'm not sure this is the reasoning, if it effects the class negatively we all loose.
Current rules are fantastic and work well, its still damn cheap motorsport as well all well know.
Current prices reflect relatively high demand and low supply; who's keen on bringing a container-load of FXRs in?

F5 Dave

11th April 2011, 17:01

I've only just seen this thread

I only really have opinion on 1


Many of these engines are getting worn. Pistons are getting harder to get. In a similar vein that the recently changed F4 restriction for 150cc 4 strokes was increased to more oversizes (158.09cc) it is suggested that the current 104cc restriction is increased to 106.2cc.

This would allow a popular, cheap & easily available 52mm KT100 piston to be used in several models (TS100, TF100, GP100, MB100, H100, A100 etc) without having to destroke the crank (an expensive exercise).

Additionally amend:
F4 2 stroke engines over 106.2cc are restricted to carburation equivalent to a single 24mm carburettor

So that would increase the avail cc of a 100cc 2 stroke 2.6cc. How bad is that?

And why should 4 strokes get an increase if 2s can't?

Otherwise you need to get a destroked crank to run a KT piston. Speedpro would be a little sore as he has had to pay this.

kel

11th April 2011, 17:27

In a similar vein that the recently changed F4 restriction for 150cc 4 strokes was increased to more oversizes (158.09cc) it is suggested that the current 104cc restriction is increased to 106.2cc

What is this, find a cheap piston and change the rules to suit?
I cant find a reasonably priced 24mm carb for the 125 so I propose we do away with the 24mm carb restriction, actual I cant find a suitably priced piston either so Ill take the extra 6.2% as well. 132.75cc breathing through a 35mm PWK, no advantage in that surely. :drinknsin
The old 2 strokes are tired and there wont be new material anytime soon, but there are plenty of after market parts available so play within the rules. If it aint broke dont fix it.

F5 Dave

11th April 2011, 17:48

Not at all, and usually I'm the staunchest 'don't fix it' proponent.

but in this instance I think its a small change that allows an easily available piston to be run. A few are running this piston now, but not many have the resource or will to de stroke a crank.

This saves a few beyond-last-size barrels, & lets face it; all the 2 stroke 100s are 30 years old now. They've been past 1st & 2nd OS. Here's another. The 150s were given another oversize option & they aren't 30 years old yet.

oh hold on that's 2.2cc over current, not 2.6

Bert

11th April 2011, 18:22

I've only just seen this thread

I only really have opinion on 1


Many of these engines are getting worn. Pistons are getting harder to get. In a similar vein that the recently changed F4 restriction for 150cc 4 strokes was increased to more oversizes (158.09cc) it is suggested that the current 104cc restriction is increased to 106.2cc.

This would allow a popular, cheap & easily available 52mm KT100 piston to be used in several models (TS100, TF100, GP100, MB100, H100, A100 etc) without having to destroke the crank (an expensive exercise).

Additionally amend:
F4 2 stroke engines over 106.2cc are restricted to carburation equivalent to a single 24mm carburettor

So that would increase the avail cc of a 100cc 2 stroke 2.6cc. How bad is that?

And why should 4 strokes get an increase if 2s can't?

Otherwise you need to get a destroked crank to run a KT piston. Speedpro would be a little sore as he has had to pay this.

I agree with you here Dave. very valid points.

I cant find a reasonably priced 24mm carb for the 125

I'll do you a deal: 24mm taiwan PWK ~$95.00 (not a KOSO; but an OKO; non powerjet). or these guys can be an option if they can get stock (140 with powerjet):
http://shop.scootling.co.nz/index.php?act=viewProd&productId=606

but in this instance I think its a small change that allows an easily available piston to be run. A few are running this piston now, but not many have the resource or will to de stroke a crank.

This saves a few beyond-last-size barrels, & lets face it; all the 2 stroke 100s are 30 years old now. They've been past 1st & 2nd OS. Here's another. The 150s were given another oversize option & they aren't 30 years old yet.

I've got a shed load of "beyond last oversized" barrels waiting for this day... Kart pistons are the best option for what we are actually trying to do with these motors (making reving race bikes).
Though the KT's start at 52mm there are other Kart pistons that start well below that; if you are willing to go hunting; a little more expensive but not as much as a RG400 piston.:shit: and actually made for racing applications.

Its been a year at lease: How about pre powervalved MX80s with a 20mm carb restriction???

Yow Ling

11th April 2011, 19:15

I voted against the changes, so rather than go edit my post, ill make a new one, speaks with forked tongue !

I am building a new 100cc engine, selecting a piston has been a nightmare, but I was ok with that because I thought it was fair and went into it with my eyes open.

Ive found a piston that will do at about $200 a pop, a much cheaper kt100 piston would give tons of options plus a few extra cc wouldnt go astray , a thinner sleeve would be an advantage.

The downside of allowing 52mm pistons is that the intention of saving the old mbs will allow 35hp engines at the other end, this suits me but i was happy to play under the old rules.

the big carb 125 stuff has been done to death

it is a bit of an anomaly that the fxr guys have 8 rebores available and skip over the first 7 to go straight to +2.00mm. the 2 strokers get about 4 rebores and dont have the luxury of wasting rebores given the investment in the porting

This has given rise to the 156 or so cc standard. One racer was arguing that a long stroke std bore was legal if the capacity was the same as the overbored std cylinder, the rules are specific regarding allowance for reboring.

Maybe instead of allowing the 100cc engine to grow , we need to curb the generosity of the diesel reboring rule

speedpro

11th April 2011, 19:22

Dave makes some good points though I wouldn't be too annoyed about everyone getting to use KT pistons without the cost. I have a few bits I could use to make more engines myself. It isn't the oversize so much as the extra revs using those pistons allow that I'm hesitant about.
Looking back I used to replace the piston in my TS100 every two meetings with another RG400 piston. That added up pretty quickly.
The only reason I'm using the KT piston now is for more revs. The MB pistons, or TKRJ, all last well and the cost spread over 4-5-6 years is neglibible. FYI - the MB pistons are good for a reliable 13,000rpm and the rings will only lose a tip now and then over 14,000rpm.

That does look a bit like I don't want anyone else getting to use the pistons I'm using.:not:

speedpro

11th April 2011, 19:25

Really I'm looking at the little increases sneaking into each class/category. Where does it end??

saxet

11th April 2011, 19:39

Well I'm ambivalent about suggestion 1 but still not for No.2.

bucketracer

11th April 2011, 20:01

Speedpro de-stroked his crank with an offset pin, so he could use a 52mm piston and stay within the 100cc limit.

With the ready availability of CNC machining, changing the stroke would not be that hard. ESE pay about $160 a crank pair to have the big end holes of their GP's bored out from 19mm to 22mm for better RGV250 rods/pistons and resultant RPM. It wouldn't be that hard for the pin holes to be off set at the same time if they needed to be.

I wonder how many people have actually taken a set of crank halves to their local engineering shop and asked them about the possibility's and cost.

Yow Ling

11th April 2011, 20:32

I wonder how many people have actually taken a set of crank halves to their local engineering shop and asked them about the possibility's and cost.

It much easier to send an email to MNZ and have the rules changed

richban

11th April 2011, 20:38

And why should 4 strokes get an increase if 2s can't?

Because the 2 strokes are making 300hp per liter. :innocent:

Gigglebutton

11th April 2011, 20:52

Because the 2 strokes are making 300hp per liter. :innocent:

How many win races? It appears to me that torque is what wins races at the moment not horse power

richban

11th April 2011, 20:57

How many win races? It appears to me that torque is what wins races at the moment not horse power

I think riding, weight, handling, and HP win races. But torque is good when you don't have some of the other bits.

ajturbo

11th April 2011, 21:02

my GT125 twin is still running STD pistons......
as with the RG50....

Yow Ling

11th April 2011, 21:05

my GT125 twin is still running STD pistons......
....

but its carbs are probably illegal so you should vote for options 2 and 2a

RMS eng

11th April 2011, 22:08

Dave makes some good points though I wouldn't be too annoyed about everyone getting to use KT pistons without the cost. I have a few bits I could use to make more engines myself. It isn't the oversize so much as the extra revs using those pistons allow that I'm hesitant about.
Looking back I used to replace the piston in my TS100 every two meetings with another RG400 piston. That added up pretty quickly.
The only reason I'm using the KT piston now is for more revs. The MB pistons, or TKRJ, all last well and the cost spread over 4-5-6 years is neglibible. FYI - the MB pistons are good for a reliable 13,000rpm and the rings will only lose a tip now and then over 14,000rpm.

That does look a bit like I don't want anyone else getting to use the pistons I'm using.:not:

fitting a new piston in your ts100 every 2 meetings,did you run any oil,my RG50 did 13500 rpm and piston would do a years racing ,the rules are ok as they are people just need to build motors that last longer,as none of mega HP two strokes are winning jack.

Gigglebutton

11th April 2011, 22:32

I think riding, weight, handling, and HP win races. But torque is good when you don't have some of the other bits.

Horse power may help at the bigger tracks, which is what high hp 2t's need to stretch there legs. Most of big hp 2t's at Mt welly are short shifting gears and don't get into the high hp apart from the front straight. The average rider, like myself, on a short circuit, needs a fat spread of power on a bike that handles. I know of 6 guys at the moment who are working on 2t's with only low to mid 20's power and all want it fat like a 4 stroke.

ajturbo

11th April 2011, 22:44

but its carbs are probably illegal so you should vote for options 2 and 2a

they are also std...

Buddha#81

11th April 2011, 23:14

they are also std...

......yet illegal Mr Turbo :bleh:

koba

11th April 2011, 23:15

Horse power may help at the bigger tracks, which is what high hp 2t's need to stretch there legs. Most of big hp 2t's at Mt welly are short shifting gears and don't get into the high hp apart from the front straight. The average rider, like myself, on a short circuit, needs a fat spread of power on a bike that handles. I know of 6 guys at the moment who are working on 2t's with only low to mid 20's power and all want it fat like a 4 stroke.
I'm another, low to mid 20's are a long way off yet though.

ajturbo

11th April 2011, 23:31

......yet illegal Mr Turbo :bleh:

by how much..??

F5 Dave

12th April 2011, 09:46

So my point is people are already using KT pistons. Do we have to make them go down the offset crankpin (not cheap to get one of those made accurately) &/or re machine crank position? 35hp? Lets be fair, no one much had more than 20hp till recently maybe mid 20s & Nigels bike was a stand out at 27. 2.2cc will make every 100 a 35hp bike?! Yeah right.

jasonu

12th April 2011, 12:29

Horse power may help at the bigger tracks, which is what high hp 2t's need to stretch there legs. Most of big hp 2t's at Mt welly are short shifting gears and don't get into the high hp apart from the front straight. QUOTE]

That is because most if not all of the recient big HP 2 strokes are really really really peaky, just have a look at the posted dyno curves.

[QUOTE=F5 Dave;1130033926]
In a similar vein that the recently changed F4 restriction for 150cc 4 strokes was increased to more oversizes (158.09cc) it is suggested that the current 104cc restriction is increased to 106.2cc. [/FONT]

When was this done?
Are you talking about the change from 145cc which was the original rule made to allow GL145's in? If this is what you are referring to then that rule change was mostly to allow FXR150's in which revived (saved) buckets.

F5 Dave

12th April 2011, 12:52

No I mean quite recently there was an amendment that gave the 150s a few more oversize CC out to 158 from perhaps 155 (can't remember specific numbers).

[edit] from MNZ site here is what it is now

F4
2 stroke 55-100cc - 104cc
2 stroke 55-125cc air cooled - 130.5cc
4 stroke 55-150cc – 158.09cc

Gives 150s 8cc to do whatever they like with, whereas 100s get 4cc & by percentage doesn't help much, we are talking available oversize pistons.

jasonu

12th April 2011, 13:13

No I mean quite recently there was an amendment that gave the 150s a few more oversize CC out to 158 from perhaps 155 (can't remember specific numbers).

[edit] from MNZ site here is what it is now

F4
2 stroke 55-100cc - 104cc
2 stroke 55-125cc air cooled - 130.5cc
4 stroke 55-150cc – 158.09cc

Gives 150s 8cc to do whatever they like with, whereas 100s get 4cc & by percentage doesn't help much, we are talking available oversize pistons.

Thanks for the clarification.

Skunk

12th April 2011, 13:33

I'm lov ing the 'only $160' type comments. I wish I had that sort of money to spare. There's a reason I have 5 TF engines sitting on my bench doing nothing. :facepalm:

I still think the KT piston is a fair and reasonable thing. You still have to spend money to get 30hp just like now. But for those without money - they get to keep their bikes running at a reasonable price.

How did the 158cc oversize rule go though? Did anyone here know of it BEFORE it was done?

Seems some can change rules without consultation and others can't even get a reply to an official rule change request.

Gigglebutton

12th April 2011, 13:39

I'm another, low to mid 20's are a long way off yet though.

Get speed pro to have a look at your motor. He and Tee Zee have helped me loads

bucketracer

12th April 2011, 13:41

Seems some can change rules without consultation and others can't even get a reply to an official rule change request.

TeeZee after prompting on this forum has tried several times to get clarification on his carb modification by writing to MNZ, but has had no reply either.

kel

12th April 2011, 13:59

I wish I had that sort of money to spare. There's a reason I have 5 TF engines sitting on my bench doing nothing. :facepalm:.

Thats odd, what I see is "I have 5 TF's sitting on my bench thats why I dont have that sort of money to spare". Sell the TF's :rolleyes:

Buckets4Me

12th April 2011, 17:47

I'm lov ing the 'only $160' type comments. I wish I had that sort of money to spare.

thats about a standard entry fee for any other type of racing ? f3 f2 f1 postie clasic sidecar motard etc

Bert

12th April 2011, 18:10

I'm lov ing the 'only $160' type comments. I wish I had that sort of money to spare. There's a reason I have 5 TF engines sitting on my bench doing nothing. :facepalm:

Ebay my man:
http://cgi.ebay.com/ebaymotors/Suzuki-TS100-TC100-GT185-Piston-Ring-Set-SZ-0-50-New-/320485662099?pt=Motorcycles_Parts_Accessories&hash=item4a9e6f1d93
~$60 would be here in a week.
if thats not to your liking then Akunar do a Yamaha RX series piston (very simliar to TF spec) for around 22 shipped if you can break a deal on shipping (dont expect it to last for more than a couple of runs)...

But value for money the KT ($65-75) fits the bill... but I know I felt sick paying for the crank work (still at uni at the time; good old student loan) and lasted another 4-5 years: before it all started to undo...:facepalm:

kel

12th April 2011, 20:45

Ebay my man:

Well said Bert, there's plenty of options and bargins if you have the time to look. The KE has been the beneficiary of many ebay bargins - KX125 Wiseco piston $9.99US, complete bottom end $100, rod kit $60 and the list goes on.
And the FXR piston from Akunar was $20 (had to take advantage of the extra displacement rule :shutup:)

richban

12th April 2011, 22:14

If it was easy everyone would do it. Mike was smart enough to mod his engine to take the KT pistons. Seams now people want an easy road. I don't think there needs to be any rule changes just coz people don't want to do the hard yards. It is almost impossible to get an FXR to 158. You will find almost all of the oversize ones are 156. My super worked engine was making just under 26hp before it died. Thats 166hp per liter. A long way off the 200 it would need to make, to catch the 2 strokes in power. Don't go crying about the 4 strokes capacity and chopping on about peaky 2 strokes that no one can ride. Coz it be bullshit. Just makes 2 stroke riders sound like whining babies.:violin::violin::shit:

speedpro

12th April 2011, 22:50

Not many of us do have heaps of money or time spare. My latest MB engine took about 6 years to get together mainly for financial reasons. KT pistons would cut costs and also allow the use of worn cylinders, but . . . . . . it also allows a considerable performance increase and you don't have to pay someone for that. Careful research, time with paper pencil and calculator, and hours in the garage filing ports.

It's a tricky one, possibly best left for those without a vested interest to decide.

koba

13th April 2011, 07:20

Get speed pro to have a look at your motor. He and Tee Zee have helped me loads

They have a long way to look...

I'm in welly but I have (and will again - If they don't get sick of it) Picked their brains a bit as well as picking the brains of our local chaps in the know. It seems I'm a brain picker. I pick my nose too.

RMS eng

13th April 2011, 13:56

If it was easy everyone would do it. Mike was smart enough to mod his engine to take the KT pistons. Seams now people want an easy road. I don't think there needs to be any rule changes just coz people don't want to do the hard yards. It is almost impossible to get an FXR to 158. You will find almost all of the oversize ones are 156. My super worked engine was making just under 26hp before it died. Thats 166hp per liter. A long way off the 200 it would need to make, to catch the 2 strokes in power. Don't go crying about the 4 strokes capacity and chopping on about peaky 2 strokes that no one can ride. Coz it be bullshit. Just makes 2 stroke riders sound like whining babies.:violin::violin::shit:

a KT100 only makes 18-20HP so for a bucket a KT piston is no better than a RM100 piston, heaps on ebay you just have to look,and if your cylinder is worn out,just get another one.rules are fine.and kelly i have 5 KE125 motors most from ebay from $40.00 US to my door

kel

13th April 2011, 15:21

kelly i have 5 KE125 motors most from ebay from $40.00 US to my door
Are you offering to sell me one? dont suppose you have a cylinder under there as well?

jasonu

13th April 2011, 16:15

Are you offering to sell me one? dont suppose you have a cylinder under there as well?

Fuck off they're mine!!!

kel

13th April 2011, 17:34

Chris still spinning you that yarn?

RMS eng

13th April 2011, 18:42

Chris still spinning you that yarn?

you got it,ones in my KX and one is to be used to make a disc valve 50cc with a derbi cylinder.

speedpro

13th April 2011, 19:33

a KT100 only makes 18-20HP so for a bucket a KT piston is no better than a RM100 piston, heaps on ebay you just have to look,and if your cylinder is worn out,just get another one.rules are fine.and kelly i have 5 KE125 motors most from ebay from $40.00 US to my door

KT100s are severely restricted porting wise hence the meagre horsepower. They do however rev and rev and rev and are well engineered to do it which makes the pistons desireable. They also come in .05mm steps and you can go to any kart shop and buy a couple of versions from a few different brands, unlike RM100 pistons.

RMS eng

13th April 2011, 21:10

KT100s are severely restricted porting wise hence the meagre horsepower. They do however rev and rev and rev and are well engineered to do it which makes the pistons desireable. They also come in .05mm steps and you can go to any kart shop and buy a couple of versions from a few different brands, unlike RM100 pistons.
rm100 pistons go in 0.25mm and 0.50mm.1977-78 have 16mm pin not 14mm

gav

24th April 2011, 17:43

I found a cheap mod that got my bike from back of the pack to top three in the last bucket race at Methven Street Races! :innocent:

I let Andy Mac race it ...... :scooter:

Buckets4Me

24th April 2011, 20:35

I found a cheap mod that got my bike from back of the pack to top three in the last bucket race

I let (someone with talent) race it ...... :scooter:

found that that worked for us as well :facepalm:

grantnz

25th April 2011, 17:01

I think riding, weight, handling, and HP win races. But torque is good when you don't have some of the other bits.

Well said that man.