Greetings,

This is a friends bike that several of us are trying to get running well. The story thus far: The bike had sat crated at a dealer until 1989 and then sold "new". The first owner put only 200 miles on it over the next 23 years. It just sat. We were told it was stored dry but inspection of the carb found that was not true.

The second and current owner had owned the exact same bike in the early 90's and when this one came available through a family member, he took it. I say this only to suggest that our friend has experience with the bike in how it should run, how to start it etc.

At first the bike was very hard to start, kicking to exaustion, but it did eventually start and run. It ran "OK" once warm in the low to mid range but cut out a lot in the top end. He first tried Seafoam and fresh gas and eventually pulled the tank for a better cleaning of the tank and petcock. Now it ran worse and poured fuel out the overflow.

Myself and another friend pulled the carb apart for a cleaning and checked the float level. We found that the carb was really dirty with dry fuel and pieces of crud. We did not disassemble the secondary side for fear of tearing the diaphram.

Once done, it was still hard to start but it ran very well. We thought we had solved most of the problems. We went for a 30 mile fire road ride with mild temps in the 70's and ranging from 2000 feet to 5000 feet. For at least half the ride it ran great. He did not need or use top end much so we are not sure on that score. On the ride back to staging, it started cutting out again at all speeds, idling rough, dieing at idle, and generally running like crap.

Except for the fuel leaking, it was as if we had not done anything to it. If it were me I would want to simply buy a new carb but it appears they are not available and/or rare and expensive.

Any ideas????????????????

Thanks,

Pete

My guess is the carb still needs a good cleaning. Take it apart and soak all the metal bits in some pine sol (search pine sol on this forum) for a few hours. Pick at any really bad build up with a tooth pick. Rinse, dry and assemble.

If its the same YDIS carb setup as the TT600 there is  a primary slide carb and a secondary CV carb. The CV carb has an aluminum diaphram so it can't be torn (if its the same as the 600).

The fuel out the overflow is likely a stuck float needle. The running good then running like crap is pieces of stuff breaking off and clogging jets/passages. Do a good soak and cleaning and it will fix the problem.

Thanks, your logic is sound and consistent with what we had thought too, guess we just did not go far enough the first time.

The fuel leak absolutly was from the float needle, We fixed that before this post. It came to us leaking, we found a lot of crap in the float needle area, reinstalled what we thought was a clean carb and it still leaked. We took it out a second time and found new crud in the area that we know was clean on reassembly. That now seems to add weight to your idea that there is still crud floating around in there.

Any sources for an actuall rebuild kit for this carb? I have not found one so far. I have several sources that have some of the gaskets and parts for this carb but not whole carbs and not some critical parts like jets and needles. Guess we would be OK with just gaskets.

Thanks again,

Pete

No good source, sorry. I just cleaned mine very well, got a new bowl gasket. I did get a "jetting" kit off of ebay from some place in Arizona. It came with a few primary carb jets and some bits to drill out the secondary.

Thanks again!!!

Took it apart again, found more crud, got both sides real clean and it runs great. We also found that the air box was assembled wrong. The clamp was broken and the air cleaner was just sitting in there, not air tight at all. Good to go.........................................