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Qkchk
1st May 2006, 18:47
I have a question for those 2-stroke finatics out there.

I have a Street Magic TR50 (Ive put it in this forum to hopefully get more interest in solving my problem...) It's a 50cc 2/stroker with CVT transmission. Wouldnt be much difference than a 150/250cc bike. My questions is:

When I start the bike, it won't idle by itself. If I want to keep running I have to give a wee bit of throttle. Not really the best solution as I'm afraid I'll wear out the rollers in the CVT trans. It WAS idling as of 2 days ago.

- I've checked the fuel tap, plenty of fuel getting through
- I've cleaned out the air filter/box, it had plenty of crap in there, which lead me to believe:
- I stripped the carb, thinking that the idle jet was blocked. Cleaned it up and re-started the bike with no improvement.

What else could be causing the problem? It's only happened suddenly, last couple of days. Could it be the CDI playing up? Maybe the spark plug? What do you think?

sefer
1st May 2006, 19:13
Have you adjusted the idle/fuel mix? (prob just the idle unless you've started using a higher octane gas in the past few days). Spark plug couldn't hurt, check the battery/charging system.

Qkchk
1st May 2006, 19:14
Adjust the idle/fuel mix?
Yep with no improvements.

sefer
1st May 2006, 19:18
Ok, check my slight edit above too :) I guess you've checked the actual cable adjustment too then?

GR81
1st May 2006, 19:36
bad/off fuel?

MrMelon
1st May 2006, 19:39
Give it a good thrash and run it on 91?

willy_01
1st May 2006, 19:49
im no master but on a dirt bike that usualy is the first sign of an up and comming rebuild, if all other possibilities have been looked at ie plugs, carb, carbon build up ect.
Im sure others with alot more experiance will be able to give you a far more in-depth answer

Ixion
1st May 2006, 19:49
Always, first thing on any twosmoker that isn't quite right in any way. Fit a new spark plug. No matter how good it looks, fit a new one.

Second thing,on any twosmoker that isn't quite right in any way.Wring its neck. Thrash the hell out of it for 10km or so. Until it's hot as hell. The difference it makes is amazing. Phoebe and Petal, after a while doddering around town won't idle , splutter and jerk at low speeds. 15 minutes of red line fang and they're completely transformed.

Third thing on any twosmoker that isn't quite right in any way is cook the zorst. And poke out the exhaust port.

If that doesn't do it, time to start worrying about serious stuff. But 99.99% of the time, those'll fix any twosmoker. Expecially wringing its nuts off.

paturoa
1st May 2006, 20:05
agree with Ixion

start with the plug - if your cheap like me, drop the plug in a jar of malt vinegar for 24 hours and give it a brush. Works a treat.

Pixie
2nd May 2006, 11:27
agree with Ixion

start with the plug - if your cheap like me, drop the plug in a jar of malt vinegar for 24 hours and give it a brush. Works a treat.
Will Balsamic do?

thesedays
2nd May 2006, 11:33
Check plugs, clean carbs & adjust idle screw / cable. Most two strokes require choke to start & only run properly once warmed up and shouldn't be ridden until they have come up to temperature (35C plus).

Qkchk
2nd May 2006, 15:11
Thanks guys for the info, bit hard to ring its nut off since its CVT best I can do is go full throttle (doesnt have a clutch). As far as Im aware there is no difference while riding its only noticeable while I pull up at the lights and it decides to conk out. Very hard to re-start. Ive tried playing with the idle mixture and idle adjustment. Doesnt matter where I adjust to, it makes no difference at all. I've done this while the bike is running and dont even hear a change in the revs. :brick:

Im almost at my wits end as this is my commuter but I cant afford to have it conk out in the middle of nowhere at 5am. :nono:

MrMelon
2nd May 2006, 15:17
Did you get a new spark plug?

Qkchk
2nd May 2006, 15:33
Did you get a new spark plug?
No not yet but will be sending Custard out on the Street Magic tonight for the 'prescribed' thrashing. Spark plug will have to be tomorrow, fingers crossed thats the problem.

F5 Dave
2nd May 2006, 15:55
New plug, clean air filter, thrash.

If you want to get carried away pull the carb & blow through the pilot jet, it may be blocked.

Qkchk
2nd May 2006, 16:50
New plug, clean air filter, thrash.

If you want to get carried away pull the carb & blow through the pilot jet, it may be blocked.
Already cleaned out the idle jet in the carb.

Lazy7
2nd May 2006, 17:14
it needs a 950cc injection :innocent:

seriously though. plug and lead would be my next guess - at least take out the plug and check it out. oh - reading this you plan to do that. guessing weak spark is holding it back.

Qkchk
9th May 2006, 20:29
Ok, finally found the time (and the inititive) to change the plug on the scoot. Hmmm, why has the whole spark lead come off in my hand when it's a screw-in style........... ok, me thinks me found da problem.

Bike is idling now (farken finally) so it was either 1 or a combination of these:

- New Spark Plug
The old one looked ok, wasnt badly fouled nor had the electrode showed signs of wear...... it looked fine but I replaced it with a new one while I was there.

- New Exhaust Gasket Ring
While I was 'down there' might as well do this. Wasnt even sure if it had one but it did and it looks a bit tired.

- Spark Lead
Came off in my hand when it's a screw in type. Cut off the end and re-did it. Nice en tight now.


Conclusion:

Weak Spark from either the plug or bad connection from the lead or both. Thanks to all who replied and pointed me in the right direction. Now I will have a better idea where to start looking next time instead of stripping my carb :slap: :doh: