FXR150 camshaft/head issues

[Damien_Toman]

http://www.flickr.com/photos/dty1/sets/72157623784414899/detail/

As you can see from the photos, my FXR150 camshaft to head interface has issues - just about to seize. I change the oil after every meeting so that is probably why it was still running. It did seem a bit down on power but it is heavy with battery, electric start, speedo etc. and my weight!). The bolts in the central head region were loose, with the one right of the plug socket sheered - it was very short and Brendan (ChCh) says it should not be. I am looking for some solution options. My local cylinder head experts can fix all this at a significant price but recommend that I look for a new (old) head, race cam and high compression piston/rings - overbored versions if possible (after all this trouble I want it to go faster :)).

Brendan is currently looking into options. I would like to have the bike ready for racing mid May. Any ideas or suggestion?

[Damien_Toman]

Henk has already offered to help with a spare engine if I can't find a solution in time (as long as he has the bits to rebuild his main engine in time). Henk should next focus on solving the world's problems - he certainly always seems to have a way to fix all bike problems :). Much appreciated Henk, as always.

I'm still interested in any other suggestions or advice to fix my FXR problems.

[Arronduke]

You were lucky to find it when you did... what made you pull the head off?

Nothing like stripping and rebuilding a motor yourself so you know it is all ok and not been screwed with by some one who has no idea....

make it go faster...LOL

[Henk]

Throw in three extra base gaskets and put in a 5kg flywheel weight to get smoother power out of corners? Oh wait that will help my performance, not yours.

[woodyracer]

i thoguht you and your bike was fast enough without cam and piston mod coming....ahahahah makes me feel like im bringin a knife to a gun fight
you'll have power on your side this yearthe TRRS.

[jasonu]

Buy a 2 stroke, that will cure all of the afore mentioned issues.

[Buckets4Me]

Buy a 2 stroke, that will cure all of the afore mentioned issues.

I was going to say throw the cam away it only slowes you down

[Henk]

Yep the stinkwheels have certainly been kicking the diesels into touch at Mt Wellington lately. :bleh:

[richban]

Interesting. I have played with 2 different FXR engines and both have shown unusual wear on the middle intake cam and head surface. Yours makes 3. I always make sure my oil level is almost spilling out the top. I checked the cam and head after Taupo and it seemed ok but it still seems strange. Sounds like some one has been playing in your engine before you got it with the bolt issues. You really have to make sure the cams spin free when torquing them down. If you want to make it go faster the question is really how much money do you want to spend. I put a $30 2mm oversize standard piston in my engine 156cc still in the rules. Tuned the carb and exhaust and it freshened it up heaps. Or you can do what I am going to do to the same engine and stroke it longer with a standard piston to get the same 156cc but it means splitting the engine and a stroker pin in the crank. Maybe $400 if you do all the assembly work yourself. Then you might as well lighten the crank, more dosh.

[bucketracer]

Yep the stinkwheels have certainly been kicking the diesels into touch at Mt Wellington lately. :bleh:

Get one of these beauties and all your problems are over.....;)....30hp 2-smoker........with none of that 4-stroke complication.

[richban]

Yep the stinkwheels have certainly been kicking the diesels into touch at Mt Wellington lately. :bleh:

Say it isn't so. say it!!!

[woodyracer]

Get one of these beauties and all your problems are over.....;)....30hp 2-smoker..............non of that undernourished fragile 4-stroke complication.

looks like a RC car engine......12cc isnt it??? ahahahhah

[Damien_Toman]

Good question Aaronduke! I wanted to check it out, re-grind valves, clean up ports, replace rings and piston if necessary etc. I'd never looked inside an FXR before. I feel better about engines that I have worked on. Glad I checked.

[Damien_Toman]

Throw in three extra base gaskets and put in a 5kg flywheel weight to get smoother power out of corners? Oh wait that will help my performance, not yours.

With the way you are catching up (on our race positions and wine side-bet) I need to make my bike go faster to try to stay ahead!

[Damien_Toman]

i thoguht you and your bike was fast enough without cam and piston mod coming....ahahahah makes me feel like im bringin a knife to a gun fight
you'll have power on your side this yearthe TRRS.

If you use your 125 bucket at TRSS, don't try too hard, and I manage to make my bike go faster, then I have a small chance :).

[Damien_Toman]

I was going to say throw the cam away it only slowes you down

I'm a 2-smoke fan too. I have an RD350LC YPVS ready to make into a track bike (I used to race those when they were the latest bikes! :))

[Henk]

It's still three one in your favour so I'm in favour of you building a slower engine.
Of course if you do build a rocketship engine I'll have to ply Ray with wine to find out what you have done.

[Damien_Toman]

Interesting. I have played with 2 different FXR engines and both have shown unusual wear on the middle intake cam and head surface. Yours makes 3. I always make sure my oil level is almost spilling out the top. I checked the cam and head after Taupo and it seemed ok but it still seems strange. Sounds like some one has been playing in your engine before you got it with the bolt issues. You really have to make sure the cams spin free when torquing them down. If you want to make it go faster the question is really how much money do you want to spend. I put a $30 2mm oversize standard piston in my engine 156cc still in the rules. Tuned the carb and exhaust and it freshened it up heaps. Or you can do what I am going to do to the same engine and stroke it longer with a standard piston to get the same 156cc but it means splitting the engine and a stroker pin in the crank. Maybe $400 if you do all the assembly work yourself. Then you might as well lighten the crank, more dosh.

I think you are right about running high oil levels. I'll always do that in future. Where can I buy an oversized piston/rings? I'm not planning to split the engine or lighten the crank - sounds far too complicated - especially without a manual. Thanks for your suggestions, Richban.

[Arronduke]

Damien... I was thinking about opening my FXR or do some racing with it first and have a look later this year.

Your experance has convinced me to open it up now.... then I know what I have... oh and ... I can learn from what you do...!

[Damien_Toman]

I only just noticed that you have an RD350LC! (your "signature"). Mega! Is it on the road or do you use it as a track or race bike?

Yes, probably a good idea to check out your FXR150 top end after what Richban said above - my problem is not uncommon it seems. The cams don't have proper ball bearings - they are built to be cheap. They are certainly not made for racing!

[Pumba]

so I'm in favour of you building a slower engine.

You can had me to that list

[Henk]

You can had me to that list

Maybe we can make a couple of restictor plates that we can quietly slide into peoples engines when they aren't looking to cut the exhaust port size to about half.
I have a couple of recpients in mind. You distract them and I'll spin the spanners.

Mind you if we go ahead with this I might have to get Damien to side track you for 15 minutes or so.

[Pumba]

Sounds like a plan to me.

[Damien_Toman]

Get one of these beauties and all your problems are over.....;)....30hp 2-smoker........with none of that 4-stroke complication.

What engine is that?

[thealmightytaco]

What engine is that?

Looks like a Rotax kart engine, designed for competition, be illegal wouldn't it?

[Damien_Toman]

You can had me to that list

Well, I could not believe that you were going so fast at MT Welly with your wrist still all pinned-up from the TRRS accident. Welcome back. I really do need a faster engine to stay on the same lap! Yes, we gotta watch Henk - talks slow but flys when in the mood!

[Henk]

Pumba is now a cyborg. Everybody knows that Titanium makes you faster.

[Damien_Toman]

Looks like a Rotax kart engine, designed for competition, be illegal wouldn't it?

Yes, it would, if that is what it is. Love the "Headbanger" quote :).

[woodyracer]

If you use your 125 bucket at TRSS, don't try too hard, and I manage to make my bike go faster, then I have a small chance :).

ahahaha, the only thing i have on my side compared to fxr's is relialbility, cant wait to do the TRRS i dont plan on winning it, i plan on having a bloody good time!, Wont be riding the cbr until june~! because the winter series is on the same date next month :(

[Dutchee]

ahahaha, the only thing i have on my side compared to fxr's is relialbility, cant wait to do the TRRS i dont plan on winning it, i plan on having a bloody good time!, Wont be riding the cbr until june~! because the winter series is on the same date next month :(
you going to have a muffler that stays on by that stage?

[Damien_Toman]

Yes, Max, having a bloody good time is what it is all about! I'm looking forward to the TRRS too. You should get the 150cc u/g to your bike, with race cams, like Peter and Bruce (from Honda - number 74) talked about. You would be winning bucket races, I expect. :)

[richban]

Where can I buy an oversized piston/rings?

Here http://www.akunar.com/STD_PISTONS.htm same as a Suzuki Raider half way down the page. They don't make a hi comp piston that fits easy. You can't argue with the price. Andrew A has been running one for a good 6 months and all good so far. I slapped one in for the wellington 2 hour and no problems. Cheapest hp you can get.

[gatch]

Here http://www.akunar.com/STD_PISTONS.htm same as a Suzuki Raider half way down the page. They don't make a hi comp piston that fits easy. You can't argue with the price. Andrew A has been running one for a good 6 months and all good so far. I slapped one in for the wellington 2 hour and no problems. Cheapest hp you can get.

Wow they have lots of stuff on there huh, this could be a useful resource..

[Damien_Toman]

Here http://www.akunar.com/STD_PISTONS.htm same as a Suzuki Raider half way down the page. They don't make a hi comp piston that fits easy. You can't argue with the price. Andrew A has been running one for a good 6 months and all good so far. I slapped one in for the wellington 2 hour and no problems. Cheapest hp you can get.

Hey richban! Much appreciated. Great price. Were they OK on delivery times? You don't happen to have a spare for sale by any chance?

[grantman]

Hi Damien
Looking at your pics of the cams reminded me of the late 80s honda XR250RE heads
The would wear and you would have to fit Teflon half shims to guide the camsaft

Just wonder if this would be a cheap fix ?
Could work as your "test head " because you could port and mod the hell out of it without worrying to much

Just an idea

[gatch]

I was wondering, It was mentioned that one member has seen a few examples like this ? Maybe theres not enough oil getting to the centre bearing ? As in pressure or oil volume etc ?

Just a thought.

[bucketracer]

http://www.flickr.com/photos/dty1/sets/72157623784414899/detail/

As you can see from the photos, my FXR150 camshaft to head interface has issues - just about to seize. Any ideas or suggestion?

Odd that its on the low load side, as the camfollower buckets would push the cam against the cam cover not the head, but the head is the hotter side.

What is the oil temperature?

Is the problem with the cam/head brg due to the oil getting really hot? would increasing the size of the oil cooler or adding another one help here?

What about ducting some air to it, and/or has removing/changing the front fairing reduced the air flow to the original oil cooler?

[Damien_Toman]

Hi Damien
Looking at your pics of the cams reminded me of the late 80s honda XR250RE heads
The would wear and you would have to fit Teflon half shims to guide the camsaft

Just wonder if this would be a cheap fix ?
Could work as your "test head " because you could port and mod the hell out of it without worrying to much

Just an idea

Hmmm... Sounds very interesting.

[Damien_Toman]

I was wondering, It was mentioned that one member has seen a few examples like this ? Maybe theres not enough oil getting to the centre bearing ? As in pressure or oil volume etc ?

Just a thought.

Exactly. Hence Richban's suggestion to overfill the oil which makes sense to me. The design is an issue - cams should really use good bearings - not metal-to-metal with a dodgy oil interface.

[richban]

Hey richban! Much appreciated. Great price. Were they OK on delivery times? You don't happen to have a spare for sale by any chance?

Yep good service. Count on about 6 days from order to door.

[Damien_Toman]

Sounds great. Thanks for the link.

[TZ350]

........ suggestion to overfill the oil............

So how does over filling the oil help?

So long as the oil pumps inlet remains "flooded" all the time, the pump does not care if there is 1 litre or 200 it will maintain oil pressure.

Over filling only provides more oil to circulate. I would look at adding external oil volume and cooling the oil.

So long as the lubricating oil film is not broken by localized over heating or over loading aluminium makes a good bearing surface. They use it in high load automotive shell brgs.

The only thing is, that its not tolerant of dirt unlike some other softer shell brgs that will bury trapped dirt particles and eventually cover them over.

Copper covered in a very thin coating of lead is another high load brg material used in shell brgs.

Bearing Failure:- http://www.engineparts.com/publications/CL77-3-402.pdf

[Pumba]

Another option for parts is R2 Enterprises, the local TKRJ importer. I do not know if they have oversize pistons however in my comunincations with them they identified a number of oarts that they do supply for the FXR. Unfortuently in the sam breath the reminded me that they are a wholesaler and will only deal with those with accounts, not the general public

[richban]

So how does over filling the oil help?

So long as the oil pumps inlet remains "flooded" all the time, the pump does not care if there is 1 litre or 200 it will maintain oil pressure.

Over filling only provides more oil to circulate. I would look at adding external oil volume and cooling the oil.
.

I am suggesting keeping the oil level at its max for the reasons you just explained. Heat. I would not go crazy over filling it coz the first big rev might just fill your catch bottle. There isn't much oil in these things anyway. It could be a good idea to add a bigger oil cooler to the mix, especially if the compression comes up. It would be interesting to find out if anyone else has seen this problem.

[TZ350]

I think your right Rich, there isn't enough oil and it would be interesting to know if others have had this problem and what sort of oil people are using.

I have heard that TKR parts can be brought directly from Japan over the net.

[Bren_chch]

i think the issue with the heads is caused by low oil level at some stage in the engines life, causing something to pick up in the journals, then we get them and service them well but rev the life out of them which causes whatever has been picked up to get worse and worse until it does what you can see in the pics.

also check the seal on the clutch cover side that the crank end goes in to, because if this has gone then oil pressure will drop to the head.

A tkrj rod kit is going to be about $180.00 plus delivery.

[richban]

what sort of oil people are using.

I use the Motul 300v Factory line 10w40. Double Ester goodness and its green.

[Buddha#81]

I use the Motul 300v Factory line 10w40. Double Ester goodness and its green.

Me.....I use Mobil 1 4T. $13 a litre from allied petrolium. I've taken this oil to 1000 race km and tested at the Goughs oil lab with clear results (only had high lead counts due to running av gas). My FXR was previously owned by Sketchy and I've put nearly 4000 race km on it on all fast tracks (ruapuna, levels, teratonga and street meetings). Other than oil changes i've never had to touch the engine inc valve clearances, for a stocker it still goes ok!

[gatch]

How hard is it on these motors to up the oil pressure ?

[Kickaha]

for a stocker it still goes ok!

Especially when you consider what it has to cart around:whistle:

[woodyracer]

you going to have a muffler that stays on by that stage?

yes...haahh to be honest my bke was running like crap that day, the pegs were too high [hence my skipping along the track} will have the bike sorted for the TRRS......will have either a race cam or piston to hopefully.....cos the HONDA guys have one and on the straight they left me in their dust....

[fi5hy]

Me.....I use Mobil 1 4T. $13 a litre from allied petrolium. I've taken this oil to 1000 race km and tested at the Goughs oil lab with clear results (only had high lead counts due to running av gas). My FXR was previously owned by Sketchy and I've put nearly 4000 race km on it on all fast tracks (ruapuna, levels, teratonga and street meetings). Other than oil changes i've never had to touch the engine inc valve clearances, for a stocker it still goes ok!

Fuck that means I have trashed that bike It should have died by now then

[Damien_Toman]

Interesting. I have played with 2 different FXR engines and both have shown unusual wear on the middle intake cam and head surface. Yours makes 3. I always make sure my oil level is almost spilling out the top. I checked the cam and head after Taupo and it seemed ok but it still seems strange. Sounds like some one has been playing in your engine before you got it with the bolt issues. You really have to make sure the cams spin free when torquing them down. If you want to make it go faster the question is really how much money do you want to spend. I put a $30 2mm oversize standard piston in my engine 156cc still in the rules. Tuned the carb and exhaust and it freshened it up heaps. Or you can do what I am going to do to the same engine and stroke it longer with a standard piston to get the same 156cc but it means splitting the engine and a stroker pin in the crank. Maybe $400 if you do all the assembly work yourself. Then you might as well lighten the crank, more dosh.

Were you able to have the standard cylinder re-bored for the 2mm oversized pistons? Did you need a larger sleeve? Do you know if the Raider 150 high lift cams fit? Really appreciate you input. Damien.

[woodyracer]

Were you able to have the standard cylinder re-bored for the 2mm oversized pistons? Did you need a larger sleeve? Do you know if the Raider 150 high lift cams fit? Really appreciate you input. Damien.

raider 150's i thought they were 2 smokers

[Damien_Toman]

Me.....I use Mobil 1 4T. $13 a litre from allied petrolium. I've taken this oil to 1000 race km and tested at the Goughs oil lab with clear results (only had high lead counts due to running av gas). My FXR was previously owned by Sketchy and I've put nearly 4000 race km on it on all fast tracks (ruapuna, levels, teratonga and street meetings). Other than oil changes i've never had to touch the engine inc valve clearances, for a stocker it still goes ok!

Sounds good to me. I might try that. I have been using Motul 10-40 4T (5100, ester, MA, Technosynthese). $65 for 4 litres. I use this same oil in my CRF250R motocross bike (used mainly for trail rides). My cam problem almost certainly goes back to before I raced the FXR (changing the oil after every meeting).

[Damien_Toman]

raider 150's i thought they were 2 smokers

From Wikipedia: "The Suzuki Raider 150 is one of the fastest motorcycles in the underbone category. It uses the same 150 cc (9.2 cu in) DOHC four-valve single-cylinder oil-cooled engine which powers its sports bike ......the Suzuki FXR150."

Damien

[richban]

Were you able to have the standard cylinder re-bored for the 2mm oversized pistons? Did you need a larger sleeve? Do you know if the Raider 150 high lift cams fit? Really appreciate you input. Damien.

Yep standard rebore. Tell the people doing it that it will be getting a thrashing. As far as cams go don't know but would think they would fit as the piston does. But if they are hi lift you might need to adjust the squish valve timing. Don't know. You should try and get a spec sheet for the cam duration lift etc. I would not buy any cam without a spec sheet. If you can get a spec I can send it to my Bro cams are his living. He can give an option. Cheers Rich

[Damien_Toman]

Thanks Richban. I'll have a chat with my local head specialist and see what he thinks. I'll see if I can get a cam spec sheet for your bro' to have a look at.

[Damien_Toman]

.......Bearing Failure:- http://www.engineparts.com/publications/CL77-3-402.pdf

Great info thanks.

[Sketchy_Racer]

The problem with the cams could just be a very simple tolerance runout in some motors.

When the engine is running, the cam surface shouldn't actually be touching the head surface, instead the oil acts a fluid bearing and prevents the surfaces touching.

What would cause it:

1 - Low oil, or low oil pressure at one point in its life. Unfortunately once this process has started you can't stop it and you will end up with the wear that you have there.

2 - Out of tolerance cam or head and cam cap. If there is not enough clearance between the cam and cam, then no matter how much oil or oil pressure there is once the motor heats up and things expand then there will be no where for the oil to fit between the two metals and it will seize.

3 - If it has been apart before and not assembled clean, the slightest amount of crap in there will be all it takes for it to start the deterioration.

Unfortunately not an easy fix, there are different methods to fix it but most would run up well into the $400 mark.

You could probably get away with grinding a lot of clearance between the centre cam and if it still has two other cam support surfaces see how long it will last with just them.

[Damien_Toman]

Yes, Sketchy, I was also thinking about just leaving some space in the mid-cam area and then Dwight from Leading Edge Cylinder Heads said he had discussed it with Richban's expert (on cams) bro' - it turns out that we all think it will work fine without the mid cam-shaft support. I am waiting on a reply about pistons from the site Richban listed. Once confirmed, I'll be ordering a new oversized piston, new valve springs and then have the cam modded by Richban's bro' (via Leading Edge). All costs a bit but while it is apart I might as well try and make it faster :).

I have to admit that I think I caused the cam/head problem when riding back from ChCh after picking up the bike in Oct 2009. I was in Napier to try Roy's Hill on my way home. It was the Napier-Taupo road close day - due to heavy snow! With Roy's hill cancelled, I filled up with fuel (forgetting to check and top up oil) and headed for Taupo through heavy sleet. It was a survival exercise and I felt the engine tighten up on me a few times but just eased off - if I had stopped it would have been dangerous - I was wet and numb with the cold. The road was closed two hours later due to deep snow. When I checked the oil level in Taupo it did not show in the viewer. I filled it up, rode to Auckland and started bucket racing soon after, changing the oil after every meeting.

[Detlev]

hi there Damien just had a inlet cam cut got the specs from Japan it was 234 degrees duration 7,8 mm lift,when I ran it with my gn 250 carb had no midrange when i ran it with standard carb and airbox the bike ran pretty good,have to play with the gn 250 carb now to get it to run properly.

[Damien_Toman]

Hi Detlev. Interesting. Timing and jetting are both likely to need tuning after the cam change (from recent discussions I've had - I'm no expert). I've ordered a standard +2mm piston kit. Hope it arrives soon. My cylinder will then be rebored to match. I'm having the cams modified to provide more lift and longer valve opening duration (I think :)). Did you leave the exhaust cam as standard? Might that be an issue?

[Henk]

Damien, you'll need to downspec the cams and reduce compression with a 5mm spacer under the barrel to get the most out of the extra 2mm. Trust me on this.

[Detlev]

Hi Detlev. Interesting. Timing and jetting are both likely to need tuning after the cam change (from recent discussions I've had - I'm no expert). I've ordered a standard +2mm piston kit. Hope it arrives soon. My cylinder will then be rebored to match. I'm having the cams modified to provide more lift and longer valve opening duration (I think :)). Did you leave the exhaust cam as standard? Might that be an issue?

Hi there damien i was advised to leave exhaust cam standard .How does one change the timing?
Would it make sense to slot the cam to adjust timing?

[Damien_Toman]

:laugh: Nice one, Henk. You couldn't write that with a straight face :).

I suggest that a little time investment in the garage, with your extensive engineering skills, might lead to more fruitful results for you going forward :D. What was that score? :innocent: ... while the competition had cam/head seizure issues :yeah:.

Hope I can have it ready for Mt Welly 15-16th May. :sunny: The piston is coming from Thailand and the cams are being done in Christchurch. I might end up just taking photos!

Have you got your engine back together yet?

[Damien_Toman]

Hi there damien i was advised to leave exhaust cam standard .How does one change the timing?
Would it make sense to slot the cam to adjust timing?

Hi Detlev. I will have to ask that question too, once I have the bits back. I'm not even sure if only my inlet cam is being modified - like I said - I'm no expert. What does "slot the cam" mean? Richban knows all about this FXR tuning and he is also very helpful. Maybe he will respond.

[Henk]

Still running on the borrowed motor since my "extensive engineering epertise" blew up my one, and I can't beat you if you're not racing (and not often enough at the moment when you are).
Sloting the cam refers to making slots in the cam drive sprockets in place of the standard holes so that you can vary the cam timing. Can give gains but make sure you mark the standard position when you get it done so that you have a known start point. Gary Johnson had this done on his GL145 and with no datum had a bit of a job to start with getting to a decent base position.

[Damien_Toman]

Hi Damien
Looking at your pics of the cams reminded me of the late 80s honda XR250RE heads
The would wear and you would have to fit Teflon half shims to guide the camsaft

Just wonder if this would be a cheap fix ?
Could work as your "test head " because you could port and mod the hell out of it without worrying to much

Just an idea

Sounds like a great idea but still tricky to do. We will go with a space and see what happens. It is the easiest and cheapest option. Thanks for the suggestion.

[Bert]

Not really up to the play on 4Ts but i did find this site a while back when hunting for honda CRF parts:
http://www.faliconcranks.com/sprocket_price.html
looks like it wouldn't be to hard to make a adjustable cam ?? if one had the required tools
http://www.hksusa.com/images_products/2613.jpg

[Damien_Toman]

Odd that its on the low load side, as the camfollower buckets would push the cam against the cam cover not the head, but the head is the hotter side.

What is the oil temperature?

Is the problem with the cam/head brg due to the oil getting really hot? would increasing the size of the oil cooler or adding another one help here?

What about ducting some air to it, and/or has removing/changing the front fairing reduced the air flow to the original oil cooler?

Unfortunately the engine does not have even a simple a temperature guage. The problem was most likely caused by low oil level - see my reply to Sketchy.

[Arronduke]

Damien.... are you looking at higher compession or porting the head?

Scary stuff... I look forward to seeing what you end up with before I blow mine up.

New heads and cylinders arn't a dime a dozen... on trade me.

I am definatly pulling mine apart to see how it looks.

I have a parts book if that helps? its a photocopy so it would be easy to copy.

[Damien_Toman]

Hi Arronduke. Yes, I'm aiming for higher compression and improving inlet and outlet flow. Leading Edge Cylinder Heads will do the work. Yes, the parts book would be awesome. Could I borrow it for a day? I've tried everywhere to buy a service manual but none are available. I'm on 0274 990 708. Thanks. Damien.

[Damien_Toman]

Still running on the borrowed motor since my "extensive engineering epertise" blew up my one, and I can't beat you if you're not racing (and not often enough at the moment when you are).
Sloting the cam refers to making slots in the cam drive sprockets in place of the standard holes so that you can vary the cam timing. Can give gains but make sure you mark the standard position when you get it done so that you have a known start point. Gary Johnson had this done on his GL145 and with no datum had a bit of a job to start with getting to a decent base position.

Hmmm. Sounds way too hard. I'll wait till all my bits are ready and then ask about assembly!

[Damien_Toman]

Not really up to the play on 4Ts but i did find this site a while back when hunting for honda CRF parts:
http://www.faliconcranks.com/sprocket_price.html
looks like it wouldn't be to hard to make a adjustable cam ?? if one had the required tools
http://www.hksusa.com/images_products/2613.jpg

Hi Bert. Excellent links. Thanks for that. Hmmm. So much to learn. I like the sound of adjustable cam timing. I also ride a CRF (250R) - no doubt you have already discovered www.crfsonly.com. I've bought heaps from them. Great service.

[richban]

Hi Arronduke. Yes, I'm aiming for higher compression and improving inlet and outlet flow. Leading Edge Cylinder Heads will do the work. Yes, the parts book would be awesome. Could I borrow it for a day? I've tried everywhere to buy a service manual but none are available. I'm on 0274 990 708. Thanks. Damien.

After you get the engine back together I would recommend a trip to the dyno. Its more money but its worth it to get it running nice and safe. Its easy to blow hi compression engines with the wrong air fuel ratios. Gives you piece of mind as well.

[Damien_Toman]

Yes, that would be very interesting. I've never tested any bike on a dyno. I will look into it as I have other bikes to work on and maybe could do more than one at a dyno session.

[Detlev]

Hey damien what size valves and springs did you order?

[Damien_Toman]

In the end I only ordered the +2mm std piston. The current valves (after grinding) and springs hopefully will be OK.

[Damien_Toman]

The piston kit has been delivered. Can anyone with a manual please provide the standard piston to cylinder bore clearance tolerances? Thanks. Damien.

[bucketracer]

As a matter of interest I found this..........HP Comparison

NSR 150 SP :39.0 hp @10500rpm ...2 stroke
SUZUKI TXR150R :26.5 hp @ 9,500 RPM
SUZUKI FXR150 :20.0 hp @ 9,900 RPM.
HONDA CBR150R :18.6 hp @ (? RPM)
YAMAHA FZ150i :14.8 hp @ 8,500 RPM
SUZUKI SATRIA/RAIDER R :16.0 hp @ 9,500 RPM
SUZUKI FX125 :13.3 hp @ 10,500 RPM
HONDA CBR125 :13.0 hp @ 10,000 RPM
YAMAHA LC135 :11.3 hp @ 8,500 RPM

I guess that will be HP at the crank, it will be interesting to see what a real world FXR150 dynos at the back wheel.

[richban]

it will be interesting to see what a real world FXR150 dynos at the back wheel.

Truck loads. With extra trailer's attached, filled with more. True will be interesting. I plan on putting mine back on the dyno before B.O.B will post the results.

[gatch]

Truck loads. With extra trailer's attached, filled with more. True will be interesting. I plan on putting mine back on the dyno before B.O.B will post the results.

No loncin on there I see.....

[bucketracer]

No loncin on there I see.....

No, but it does have the FXR150 ahead of the CBR150. Interesting......

[Bren_chch]

No, but it does have the FXR150 ahead of the CBR150. Interesting......

those figures are so far out! they must just flip a coin