86 TT 600 misses HELP!!!

I have owned this one since new. Very low hours. Bike misses at high rev doesn't run like it used to. I have tried new CDI, New Stator, Jets, Needle position, synchro carbs. Had the carbs off a zillion times. I read another about cracked intake boot. I don't see any cracks.

Any suggestions greatly appreciated.



Welcome to TT.......... :naughty:

What color is the spark plug,Use some WD40 to check for vacum leaks around the carb. and carb. mounting..

Run it at nite in the dark and look at the plug wire to see if there is any spark leakage..

When you say missing I'm asuming its running like crap... :naughty:

Does it have good flow from the tank to the carb..?

I will check for leaks. Yes it runs like crap.

Thank you,


Let us know what you find... :naughty:

Unplug the kill button and take it for a test ride. Yamaha had a bulletin on this in the '80s. Had it happen to me once some years ago... If it runs better without the kill bitton hooked up you need a new one.

Thank you, I'll be working on it tomorrow. I will post what I find out. Does any one still make an exhaust for the old beast?? I was thinking of making one. Keeping my header, and having a tube bent then add a silencer/spark arrestor. Any suggestions?


Supertrapp makes several different types of universals if you don't mind getting the connector pipe made for you. If they still have the E.A.R. model it is quiet enough to pass AMA dual sport event inspection and much, much lighter than the bazooka on your bike now. I liked the one on my XT350 and have one on my XL600 now. You might have to call them though. Their web site isn't the best and doesn't really show everything available.

FMF also has some universal 4 stroke mufflers. I don't much about their stuff though. The FMF 14" Ti4 that I tried on the XL600 is super light but it had the neighbors threatening me. Maybe the 16" or 17" is quieter, I don't know. I just stuck the Supertrapp EAR back on my XL600 last night and put a jet kit in it. Overall, I like the Supertrapp better anyway since you can play with the number of disks. I had to go from 12 to 8 for a reasonable combination of sound and power.

Like grreatdog said the Supertrapps are good. The IDS is also a good setup. It has the discs but they are inside and give a nice exhaust note while still being efficient in the power department. The pipe piece you'll need is a simple S bent pipe that should be easy to make or have made.

Thanks for the info. Time to go tinker in the garage and see what I can do to the TT600.

Please keep us updated MXM, I just started restoring one of these so anything you find is much appreciated.

What about the head pipe? are they the same from the 550s and 600s? My header pipe is starting to rust out, so im really hoping to find something in stainless.

What a great weekend! It runs like it should for a stocker. I took off exhaust painted it. Took off carbs dropped both needle pos. 1 groove 3 from top, raised float level, new main jet, one size larger pilot jet, cleaned and blew out all orifices, synchro carbs, inspected and cleaned intake tubes, I am not sure what did it but it runs great and looks a little better. I need to find out where to get a tank cover or new tank thats the only really bad looking thing on the whole bike.

I will second the Clarke tank. I hated the way it looked on my XT350 and didn't like being a rolling gas station. But it fit perfectly, held up to monster abuse and ended my carb problems from the old tank rusting from the inside out. Like the Car Talk web site said about Chevy Vegas, I think those old Yamaha tanks were out of compressed rust.

Is the TT600 a Yamaha? If so, my dads friend has one that is sitting in a barn. I took it for a ride about 9 years ago and I think it has more balls then my 426.

Yes it is a yamaha, It has great power. Where is the bike now?

Yes it is a yamaha, It has great power. Where is the bike now?

In a barn in Ohio. It belongs to my dads friend. He bought it new and hasn't riden it in probably 3-4 years. It's a monster. I had XR600's and this bike would destroy them.

It's a monster. I had XR600's and this bike would destroy them.

Sounds about right. :naughty:

YEE..HAA!! mmm after the $2700 rebuild on my TT600 i did everything but install a fule filter and flush the tank ur bde bde bde thats all folks

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now