Tl125 Hot Running Issue

[nozzaamazon]

Hi, wonder if you can help.

I have just got a new to me tl125 running, fitted new original carb, coil, plug etc and set it all up. However after riding for 10-15 mins when I drop the revs to idle it won't pick again. Opening thottle just causes a stuttering farty idle. if I ride it along on idle, after a few mins it will eventually pick up.

Check for carb air leak and blocked tank vent, but nothing evedent. I have a bakealite original looking carb heat shield fitted too, so not sure if it could be heat on carb bowl. Any ideas? Thanks

[btc273]

Does it seem to run ok when cold, and then slowly gets worse as it warms up? Does the choke make any difference?

[nozzaamazon]

Hi,

Yes she runs fine when cold (has some off idle hesitation, but assume this is the standard 'cough').

I have not noticed it as gratual, engine runs fine then when I reach a stop (after 10 mins or so riding) and let here idle she would rev.

I have played with the choke during this fault and putting the choke on stalls the engine. If I pull the choke on and then off quickly I can sometimes get the engine to rev again as normal, but more thimes than not it does not have an effect.

When I do get it to 'clear' it seems to run okay as long as I don't drop back to idle.

Thanks for your help!

[thats_a_five]

Sounds to me like it is time for a thorough cleaning of the carb. Check all the little passages and jets, also and inlet or in-line fuel filters.

[tayld]

When checking the carburettor see if the float height is correct to the specification. There can be some different figures quoted but a careful check should find the right value for your carb.

Another check worth doing would be look at the contact breaker points with the engine running. If there are a profusion of sparks the condenser might be on its way out.

Hope this is of help.

[nozzaamazon]

Thanks all, will check as you advise and report back....

[helm]

Hi

check that the choke is closing fully, take it apart and check i have have had the same problem

cheers

[nozzaamazon]

Hi All,

Just a quick update. Stripped carb, set up float, checked choke and fuel filter. Nothing seemed obvious.

Checked points and there was some sparking, but normal I think. Then I thought I'd check the timing while I had the cover off. Then I found by adjusting the timing I could switch the fault on and off! So I have adjusted timing to get rid of it then rode for a good long while and it seems sorted!

Thanks for your help!

Mat

[grooster]

Glad to hear you have this problem solved! I have a pair of TL125's I'm bringing back to life. One is a 73 very tired barn find, the other a well kept 75. Now that you have the bike running well it's time to work on the suspension. Rear shocks are a must purchase to be competitive. And if that's the direction you're headed, consider the engine mods available. I chose the CB550 piston upgrade for the 73 and will later install the 150 big bore kit on the 75. Big difference in power! A set of modern trials handlebars help, too.

Good luck!