Dies at idle but runs fine [Archive]

EJK

11th April 2009, 00:05

Evening. My 2 stroke 125cc 1987 won't seems to start (The battery is perfectly fine). But when I bump start it, it will run fine till I rest the throttle. The bike dies at idle. Even after running around the block & fully warming the engine up (without stopping), the engine still dies when the bike comes to a halt (no throttle) and still won't start by pressing the button/ kick.

The spark plug was replaced 300kms ago. Yes the bike's got petrol and engine oil.

Thanks, help would be appreciated.

P.S. A red "C" light engages when the bike's not running. What does that mean?

98tls

11th April 2009, 00:09

Would imagine its c for charge,i would say you need to adjust the idle,as in turn it up so it does,the by product will be charging the battery.Or possibly ive just had to many bourbons.

EJK

11th April 2009, 00:13

Would imagine its c for charge,i would say you need to adjust the idle,as in turn it up so it does,the by product will be charging the battery.

Still bike won't start even when light throttle is applied. Before it went out of order, the bike seemed to backfire gently *pufft* *pufft* while engine breaking.

That brings to another question. Is engine breaking bad for 2 stroke bikes?

Edit: And no, I never rode around with the choke on.

98tls

11th April 2009, 00:17

Still bike won't start even when light throttle is applied. Before it went out of order, the bike seemed to backfire gently *pufft* *pufft* while engine breaking.

That brings to another question. Is engine breaking bad for 2 stroke bikes? Engine breaking is bad for any bike,engine braking however is a rare thing on a two stroke though if you have some rejoice your a braver man than me.

EJK

11th April 2009, 00:21

This similar problem happened once before, but it was solved by just replacing the spark plug. But I surely doubt that the bike will need a new plug every after 300-400kms! Or does it?

98tls

11th April 2009, 00:23

Wouldnt imagine so mate,shes a beauty but getting on,wonder if the exhaust is all coked up?

EJK

11th April 2009, 00:30

Wouldnt imagine so mate,shes a beauty but getting on,wonder if the exhaust is all coked up?

I'll check that out tomorrow. So I just take out the pipe and look through it right?

Magua

16th April 2009, 17:31

The Pastor

16th April 2009, 18:07

is your idle adjust set too low?

Sollyboy

16th April 2009, 18:51

Hi your idle maybe to low , if not and it runs ok on part or full throttle its most likely be a blocked idle jet or the idle mixture screw needs adjusting or both , repco sell a carb cleaner in a spray can but it need be used when carb stripped

EJK

20th April 2009, 15:24

Spark plug replaced. Still no go.

Hi your idle maybe to low , if not and it runs ok on part or full throttle its most likely be a blocked idle jet or the idle mixture screw needs adjusting or both , repco sell a carb cleaner in a spray can but it need be used when carb stripped

Maybe your oil mixture is out.

I think you guys are on the money right there.

The Pastor

20th April 2009, 16:18

see if you were in auckland still we'd have this problem sorted by now

t3mp0r4ry nzr

20th April 2009, 17:09

Str8 Jacket

20th April 2009, 17:19

This similar problem happened once before, but it was solved by just replacing the spark plug. But I surely doubt that the bike will need a new plug every after 300-400kms! Or does it?
Like the others say, check the spark plug, you're bike may not be running properly.

Wouldnt imagine so mate,shes a beauty but getting on,wonder if the exhaust is all coked up?

Yeah, go on mate. Decoke it anyway, it's *fun*. Also checking the baffles in the pipe, my poor lil A100 died cause the "rangi homemade" baffle we made for it got all clogged up. I of course did not know this and got a new piston, rebore rings etc after stripping the bike completely and checking EVERY fucken part and it still didnt wanna go properly! Of course as soon as the baffle was removed it was sweet! :rolleyes:

WOOT! I love 2smokes! :wari:

thehovel

20th April 2009, 17:40

hi moving over the strait will make any bike run funny:cold:. Try making it breath properly,clean the carbs and the baffles. these are the most common fault on 2strokes. Also check the main fuse for cracks, unscrew the fuse and bend it GENTLY!!! :gob:If there is any cracks it will break in two.:Oops:. Regards Richard

EJK

20th April 2009, 20:52

Thanks everyone. Will clean the pipe and carb and see how it goes.

That brings another question, what makes 2 stroke bikes blow very well? How did GIJOE1313's A100 blow?

t3mp0r4ry nzr

21st April 2009, 09:17

Thanks everyone. Will clean the pipe and carb and see how it goes.

That brings another question, what makes 2 stroke bikes blow very well? How did GIJOE1313's A100 blow?

no, 1st thing to do is also the easiest, unscrew the plug and check it! if the plug is good, proceed to checking air filter, then check to see if carb is gummed up or blocked pilots!

xwhatsit

21st April 2009, 10:11

That brings another question, what makes 2 stroke bikes blow very well? How did GIJOE1313's A100 blow?
What do you mean `blow' lol?

EJK

21st April 2009, 10:19

no, 1st thing to do is also the easiest, unscrew the plug and check it! if the plug is good, proceed to checking air filter, then check to see if carb is gummed up or blocked pilots!

Yep the plug looks fine.

What do you mean `blow' lol?

Haha well, during the Cape Reinga Challenge his A100 got a hole on the cylinder head didn't it? Is that common? lol

xwhatsit

21st April 2009, 10:49

Yep the plug looks fine.

Haha well, during the Cape Reinga Challenge his A100 got a hole on the cylinder head didn't it? Is that common? lol
You want your bike to do that lol? You want it to blow up very well :pinch:

Two strokes are a bit more sensitive to setup, yeah. That's why you make sure it's got exactly the right sort of plug, ignition timing is spot-on, and the carb is operating exactly as it should be.

But on the plus side, if you do hole a piston like Pippi did, it's as cheap as chips to chuck a new piston and rings in, and very simple even monkeys can do it. The bike would go better than ever afterwards too.

EJK

21st April 2009, 19:31

No I'm not planning on blowing this bike! (Atleast till next week)

Today I was talking to a guy at Cycletreads. I asked him about a puncture repair kit for tubed tyres, well he said "it's not a job you can do at the side of the road..." Hmmm that worries me...

But yea, will clean carb and clean the baffle waffle. I think it's the baffle...

Laava

22nd April 2009, 10:44

GIJoe's bike holed a piston because the baffle flew out of the exhaust! He wanted to fix it with damper but we bandaged her all up for the transporting home. Did he fix 'er?

EJK

22nd April 2009, 13:14

I think he got it going about couple months ago with his fixing crew. Not sure.

Still worries me...

EJK

23rd April 2009, 15:03

OK I took it to the shop this morning. They opened it up and found something.

It was not the dirty carb.
It was not the spark plug.
It was not the dirty baffle.

The bike's cylinder head(?) of somekind's pin was loose, and that rattled and made a hole on the head. Hence the low compression and the "why-won't-it-start" theory. God knows how I safely rode it down to the shop.

The parts going to take 7 to 10 days to arrive. Mean while I'll be fucked :bye:

Taz

23rd April 2009, 16:46

e. Mean while I'll be fucked :bye:

Isn't that a good thing??

EJK

23rd April 2009, 16:49

Isn't that a good thing??

lol nah not really...
I was going to go on a trip with this bike next week. Now that is cancelled, I'm just feeling fucked beyond all measure.

Taz

23rd April 2009, 16:51

lol nah not really...
I was going to go on a trip with this bike next week. Now that is cancelled, I'm just feeling fucked beyond all measure.

Hire a bike?

EJK

23rd April 2009, 16:53

Hire a bike?

Tried every single bike hire shop in Christchurch. No ones willing to hire a 250 to a 19 year old.

Besides, the repair is going to cost me enough already.

Well I will still have the plan with me.

Laava

23rd April 2009, 17:00

Right, that will be the ring end gap locating pin that has spat it ? So you need a new piston/rings put in? Bugger! Hope things work out for you dude!

EJK

23rd April 2009, 17:07

Right, that will be the ring end gap locating pin that has spat it ? So you need a new piston/rings put in? Bugger! Hope things work out for you dude!

Yes, they said the damage was.... unnatural. He wants me to see it so I'm going back there to have a look at it myself. Might take a few shots.

I am expecting to have the top half of the engine replaced (well thats what he said!). :bye:

Madmax

23rd April 2009, 19:05

On two stroke engines the ring pin
stops the rings rotating into the ports!
if you get away with piston and rings your doing well

:blink:

EJK

23rd April 2009, 20:20

On two stroke engines the ring pin
stops the rings rotating into the ports!
if you get away with piston and rings your doing well

:blink:

lol thanks, I bet you don't get these on your ZX10Rs. I'm not sure tho, I'll get a copy of the parts order/ damage list too.

Heck it's not a write off or anything... right?

Mikkel

23rd April 2009, 21:30

Madmax

23rd April 2009, 22:45

lol thanks, I bet you don't get these on your ZX10Rs. I'm not sure tho, I'll get a copy of the parts order/ damage list too.

Heck it's not a write off or anything... right?
just hope all the bits went out the chamber!
My old H1 two stroke tripple did until i got to grips with this stuff,
15 types of racing rings ETC.
Maybe the should be a two stroke tuning/knowlege thread?
I can help start it!
Two strokes are a sort of art

:blink:

EJK

24th April 2009, 00:16

One thing to check for these symptoms would be whether you accidentally have managed to screw your idle-adjuster out of the carb... It can happen and it's very frustrating. DAMHIK

Where were you planning to go this weekend?

Not weekend but through out all next week from Monday to Saturday. Invercargill... Sigh.... :(

Well it's a good thing that Canterbury Rides found out the problem today. If they didn't (Or if I didn't take it for a service), I might have been trapped in Ashburton! or make it to Hornby if lucky...

just hope all the bits went out the chamber!
My old H1 two stroke tripple did until i got to grips with this stuff,
15 types of racing rings ETC.
Maybe the should be a two stroke tuning/knowlege thread?
I can help start it!
Two strokes are a sort of art

:blink:

lol What is actually more complicated to fix/ repair? 2 strokes don't have valves don't they? Which means they don't have any cam chains/ valve clearance things to do etc?

The Pastor

24th April 2009, 11:40

Not weekend but through out all next week from Monday to Saturday. Invercargill... Sigh.... :(

Well it's a good thing that Canterbury Rides found out the problem today. If they didn't (Or if I didn't take it for a service), I might have been trapped in Ashburton! or make it to Hornby if lucky...

lol What is actually more complicated to fix/ repair? 2 strokes don't have valves don't they? Which means they don't have any cam chains/ valve clearance things to do etc?
2t are way eaiser to work on. but dont last as long

EJK

24th April 2009, 15:14

Went to the shop today. The guy showed me what was wrong (as pic below).
It's not a major fucked I think. Just a little "pinch", but I should be happy that it is found soon than later.

Yep, the rings are still intact.

Also because the interior of the engine (chamber?) is all scratched, he said it'll need to be "re-bored". Well wouldn't that make a leak when the piston is compressed?

Laava

24th April 2009, 15:16

Cool. So new piston and rings and off you go then?

EJK

24th April 2009, 15:19

Cool. So new piston and rings and off you go then?

Yep I guess so. Maybe new gasket set too.

Alas, in the end, I will have peace of mind... for now.

Squiggles

24th April 2009, 15:26

Also because the interior of the engine (chamber?) is all scratched, he said it'll need to be "re-bored". Well wouldn't that make a leak when the piston is compressed?

New oversize piston + rings, size dependant on what it is currrently and how badly scratched the old bore is... Then have the cylinder bored oversize (The new piston will be needed for this step), put it all back together and have it checked over as far as tuning goes. Cant remember exactly but to do Jafa's RD350 (2 stroke Twin) was in the region of 150 for a rebore (if i remember correctly) and 200ish for piston+rings for the two cylinders. Then some gaskets, little end bearings and time

EJK

24th April 2009, 15:30

Hmm cheers. Yea I'm expecting a dent on my wallet. My new bike's got to wait a little more longer :(

tychver

24th April 2009, 20:41

If it's a Nikasil plated bore rather than a iron liner it'll be more expensive.

koba

24th April 2009, 21:38

OUCH!
One thing to consider is WHY?
What cused it
Make sure the timing is correct, the mixture is correct and that the oil pump is correctly set.
Also make sure the exhaust isn't clogged up.
It would be shit if you put it all back together to have it happen again.

Oh, and two major points about a 2 stroke:

Warm it up, not doing so can KILL IT!
Make sure you never ever let it run down a hill with the throttle closed.
Your bike probably has oil-injection (where you put it in a tank that needs to be topped up) This is directly linked to the throttle control.
Rolling down a hill with the throttle closed and the revs high will result in fuckage from hell.
Reading between the lines a bit from you earlier posts this may have somthing to do with your issues...

Good luck with it aye, and remember if you spend a few pingers on the motor at least you know it is all good inside now :)

EJK

24th April 2009, 23:49

OUCH!
One thing to consider is WHY?
What caused it
Make sure the timing is correct, the mixture is correct and that the oil pump is correctly set.
Also make sure the exhaust isn't clogged up.
It would be shit if you put it all back together to have it happen again.

Oh, and two major points about a 2 stroke:

Warm it up, not doing so can KILL IT!
Make sure you never ever let it run down a hill with the throttle closed.
Your bike probably has oil-injection (where you put it in a tank that needs to be topped up) This is directly linked to the throttle control.
Rolling down a hill with the throttle closed and the revs high will result in fuckage from hell.
Reading between the lines a bit from you earlier posts this may have somthing to do with your issues...

Good luck with it aye, and remember if you spend a few pingers on the motor at least you know it is all good inside now :)

No engine breaking? Then how do I run down a hill? Full throttle? :lol:

Pull the clutch?

Squiggles

25th April 2009, 18:07

No engine breaking?

You dont get engine braking like on a 4 stroke... Engine breaking however :msn-wink:

koba

25th April 2009, 18:46

No engine breaking? Then how do I run down a hill? Full throttle? :lol:

Pull the clutch?

Match the throttle to the speed.
Don't spend ages with the throttle totally closed and the engine spinning hard.

gijoe1313

27th April 2009, 22:53

Wow :gob: Just caught up with this thread ... sounds like you were in luck! :yes: The biker gods smile upon you again! Pippi just needs a new union bolt which was fuxx0red from the last spannering gorilla! :innocent:

New baffle in and just need that one little itty bitty part :lol:

Glad to hear that you are sorting your ride out ... ahh two strokes, thats what they do and thats why we luvvies them so :love:

Remember, you are well ahead of the game ... it was FREE! Free is good! :2thumbsup