Hey all,

Looked for this on other posts, but nothing seems to cover this one... My boys old ty80 starts lovely, ticks over and revs perfectly... But when riding it bogs and stops, obviously when in gear, pull the clutch in, rev it through... all great again. Fuel fresh, carb and filter clean.

Any ideas anyone?

Bezerk

obviously diagnosis at this distance its just guesses... however, here's a few.

• At a basic level, bogging when the bike heats up spells rich mixture.. but....
  
• Have you had the plug out immediately post bog (to see if its rich or lean)
  
• Does it smoke heavily when its bogging (rich..carb float issues, does fuel leak out of the overflows)?
  
• have you tried applying choke mid bog (if its weak, this will perk it up at low revs, if its already rich this will kill it completely)
  
• Have you tried removing the fuel cap just in case the tank breather is blocked.
  
• how far do you ride before it bogs (if its +5 mins it might be overheating.. ign timing)
  
• Does the exhaust note sound strangled or muted (clogged exhaust... overheating)
  
• have a look at the ignition timing marks.. are they correct
  
• It could be a dodgy plug/coil electrics but this doesnt sound likely given the description. Generally these work or they dont.
  

So, some ideas there... good luck

Dom

If bogging means the motor dies as the throttle is opened, it may be a blocked or partially blocked pilot jet (lean mixture as throttle opened).

dombush's choke test will test this possibility

If bogging means the motor dies as the throttle is opened, it may be a blocked or partially blocked pilot jet (lean mixture as throttle opened).

dombush's choke test will test this possibility

Yup exactly what I was going to say - I have several TY80's and the pilot jets are forever blocking as they are soooo small and the tiniest bit of rust/dirt from the tank blocks em good and proper....

Guys,

Thanks for the reply...

It doesn't bog or splutter until there is a load (ie, in gear and moving) then it behaves exactly as if it was a fuelling issue (it sound/feels perfect when ticking over or reving it up, even when I shake it around)

See why this one is a strange one?

OK, but this is exactly the symptoms I get with a blocked pilot [on a TY80], so I would check this first, and then move onto the more serious stuff.....

Thanks,

I'm on it... I'll keep you informed.

try riding it without the airfilter in,if it runs ok without the filter, then theres not enough air getting to the carb making the mixture rich whenyou put it under load

Edited February 14, 201115 yr by gazer

try riding it without the airfilter in,if it runs ok without the filter, then theres not enough air getting to the carb making the mixture rich whenyou put it under load

Done that one, but thanks for the thought... talked to a bloke at Gordon Farley today and he had the thought that it could be electrical condenser, points, as its occurring under load, fair point!, also we kinda agreed its unlikely to be a carb issue as it idles, revs cleanly whilst standing (though Im ruling nothing out )... thoughts?

A friend of mine years ago had a similar symptom. Turned out to be that the muffler was clogged. A fresh repack and all was good again. Might be worth looking at.

MB

A friend of mine years ago had a similar symptom. Turned out to be that the muffler was clogged. A fresh repack and all was good again. Might be worth looking at.

MB

Thanks for that ill... check it out and report back.