TT250 wont run, Help!

[Damz]

Hi guys,

Iv got a trusty old TT250, 1981 to be exact!

This is my first bike, and its always run well, at least, its always gotten me up and down the beach with no issues.

I thought I would treat the bike to a carb clean out, brake servicing, and a few other minor maintenance type things that a local bike shop could do to keep the beast happy.

Nearly $500 later, the bike stops on a dime, but wont run like it used to!

Heres the situation as best I can explain.

Bike starts great, first pop. doesnt run to its full potential for about a minute, the odd stutter etc, but its always been like that till it warms up a little I guess. No probs.

However, after say, fifteen minutes of normal riding, itll die. sometimes it will put-put-put out (Feathering the throttle will sometimes bring it back to life before dying), other times it will just stop running, as though someone has ripped the plug out! Very weird when at 60-70kph along the beach it cuts out. Pull the clutch in and theres silence, Let it back out and the motor turns over, but theres not a single pop of life.

Let it sit for 2-5 mins, and it will start up again, and run just beautifully... For a few minutes, then it dies again.

I took the bike back to the shop, they were little help, and didnt really want to know about it. Disappointing seeing as the bike has always been great in the past.

So now I turn to kiwibikers!

Heres some pics of the plug which was supposedly replaced when serviced. I was told by a friend to check it, but I dont really know what Im checking for..

http://i43.tinypic.com/nx3j2v.jpg

http://i39.tinypic.com/2duwe3r.jpg

Thanks in advance for any ideas!

[tri boy]

Get the shop to recheck the valve clearances, (might be a bit tight), also the fuel delivery to the carb, (might have a slight kink in the line), also the tank breather.
Plug seems reasonable, but doesn't look new, unless that is recent sand and salt water on it.
Approach the shop politely and I'm sure they will see you right.

[FJRider]

Sounds like a fuel issue. But also sounds like COMPRESSION issues too. Beaches are bad for this... the sand does get in...

[98tls]

Possibly a coil breaking down when hot.

[tri boy]

Possibly a coil breaking down when hot.

True dat
Hard for the local KB experts to pin point faults for those in need as there is nothing like being there to help out.
I propose a "Super KB Fault Finding Team" that is funded by the Govt, to fly us all around NZ in a private jet, (with super models), to help riders sort out faults. All those in favour say Yay, all those against, Nay.
The Yay's carry the vote.

[Taz]

Faults with bikes or faults with KB'ers??

[CookMySock]

I would replace that plug - its rather dark and covered in crap and looks like its been in the bike for years.

My bet is you have dropped a tiny bit of shit in the carb while you were in there trying to do it a favour.. Try draining and flushing some fuel through the carb and see if it comes right. Did you "clean" the carbs really carefully in a clean clean place?

Steve

[camchain]

I had one of these in 1981, I went through 3 cams before I found out you have to bleed the oil pump when changing the oil.

Fuel seems like a likely cause and easier to trouble shoot than electrics so start there. Clean carb again, pull out the jets and clean thoroughly. Maybe clean out your fuel tank and filter (remove petcock to get at filter). As mentioned above, check the tank breather hose isn't blocked, this can cause fuel starvation. Did the shop change float level? Sticky float needle? Was the carb reassembled properly?

Check your spark by pulling plug and earthing it on engine and kick it over (keep it earthed and don't zap yourself). Check again immediately when engine dies. Any spark? Is spark weak/intermittant when hot? Easier to check if you have someone kick while you get up close to eyeball plug.

[Taz]

I had one of these in 1981, I went through 3 cams before I found out you have to bleed the oil pump when changing the oil.

Slow learner?? Was this not in the owners manual?

[Damz]

Wow thanks for all of the replies!

I tried VERY politely with the bike shop, in the end the said its an old bike and its not their problem. Wont be going back to them in a hurry, not happy.

I didnt clean the carb myself, but assume it was done in a clean area, and reassembled correctly. I wouldnt know how to pull it apart and clean it out again, wish I could!

I might try putting some carb/injector cleaner in the tank, that might free up some dirt that could be hanging around?

Plug will be replaced tomorrow, Ill also check for kinks in the fuel line, and blockages in the breather pipe.

Will take it for a spin and see how I get on. If it does die, ill put a spare plug in the boot and see if its making any spark. Cant wait to get it sorted!

Thanks again

[Damz]

Ok, breather pipe is clear. Fuel line is perfectly straight. I put in a new plug.

Took the bike to a place that was mainly stoney tracks and a bit of dirt, rode it round for 30 minutes, no problems.

Rode over into the dunes to give it a bit of a workout, and after 5 minutes of hauling my 90kg ass through soft sand + up and down dunes, it starts to die. However I kept the revs quite high and it didnt, but as soon as I let them fall it wouldnt let me bring it back to life. As quick as I could, I got the old plug out of my bag, put it in the boot (lead), earthed it on the exhaust and gave it a kick. There was spark. So I put the boot back on the plug on the engine, kicked it, and it started. It started up fine, and I rode around on the dirt for another 15 minutes, no problems.

Iv never really ridden on anything but sand since the problem started happening, but now that I have, I think its a heat related issue.

When the motor gets hot, what would stop it running like this? Possibly the coil breaking down as mentioned above? Where is the coil, is it replaceable?

Thanks again, Damian