YTrouble, Part II [Archive]

Six Stroke

10-08-2005, 10:20 AM

So I got the YT back together, and another problem reared it's ugly head. It has a habit of running poorly and/or dying sometimes. Not all of the time, but sometimes. I've cleaned out the exhaust, removed the silencer, cleaned the carb, cleaned the petcock, swapped the needle and seat, tweaked the carb a little in each direction, and tried everything I can think of as far as the fuel system goes. One funny thing about it is if you put it in neutral when it starts to die, it'll come out of it.

It really seems like a fuel problem, but I've gone through the whole system. I checked coil ground for the hell of it, and that seems fine also.

I'm stumped.

edog

10-08-2005, 10:33 AM

Check the oneway valve that comes off the carb it lets air in and keeps thing out.If it is faulty it will cause some of those problems.

Six Stroke

10-08-2005, 10:57 AM

You mean that vent hose on the side?

edog

10-08-2005, 10:59 AM

Yes,that is what i am talking about.

Six Stroke

10-08-2005, 12:35 PM

I'll check that out.

I hope it's that simple.

Six Stroke

10-09-2005, 12:52 PM

Nothin'.

Just out of curiosity, what kind of compression should I have when I check it?

EvilMooseofDoom

10-09-2005, 01:24 PM

You might want to focus on the ignition side....

Six Stroke

10-09-2005, 10:23 PM

I tried a different coil last night, and it still acts the same. I don't have another CDI to use for testing here.

Other news -

I did a compression test after it had been running for 5-ish minutes, and came up with 78 psi.

The plug is dry and dark gray/black.

MTS

10-09-2005, 10:25 PM

78 is loooowww......should be at least 100.

Six Stroke

10-09-2005, 10:43 PM

That's what I thought, but when it's running right, it runs great. The dying problem seems to turn off and on like a switch, much like fuel starvation.

On a side note, has anyone ever successfully swapped a 175 top end on to a 125 lower end?

rustbucket

10-10-2005, 08:28 PM

Ah I see you have found the joys of owning a tri moto 125. Did you take out the pilot jet in the carb? How about this does it start to die when you turn. if it does then your crank seals are smoked. They are available and their like 3bucks each and you can replace them without splitting the case but if you seals are bad you crank bearings are bad to. I may have a very slightly used piston and rebored cyl if my buddy doesn't need it.