All the advice on settings above is exactly what is suggest. I don't know the Yamaha carb well but I do know the equivalent Kawasaki one. On aKLR650 this happens whenever the bike is left to stand more than a few months and are caused by some of the pilot circuits getting blocked. Simply cleaning the jury is never enough. I suggest you try and clean all the different passages on the carb using an aerosol cleaner - simply put the small borr tube into each opening and make sure it comes out somewhere else. Good luck.

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__________________
Martin

finally back on the road again


http://awayonmybike.blogspot.com/

TT600.. These things are a pain in the arse even when they're perfect.

I sold my TT600RE because it literally could not be fixed. It was broken from new. They were thrown together by Yamaha with mis-matched parts and never ran right.

The float height on these bikes is CRUCIAL. They flood very easily and won't start if the level isn't perfect too.

Yours will start with the choke though. HOORAAAHH. Your problems aren't that bad.

I would also follow the advice here and start with your pilot circuit and idle settings.

The bike has been sitting for 12 years. You say you cleaned the carb. I've read a MILLION threads and had a thousand customers who say "I've cleaned the carb and it still won't run".

You haven't cleaned a carb unless you've stripped it down to it's individual components. Every air way, fuel way, o-ring and spring. Ideally you want to soak it in solvent in an ultra-sonic bath and then use compressed air with a fine adaptor to blow out all the passages. Then you want new o-rings, new gaskets and then set up the carb to the factory settings.

My advice is to get some brake cleaner or 'Power start and spray a very fine mix into the air box and kick start it. If the electrics and compression are fine then it will burst into life and rev it's tits off for as long as you keep spraying. Don't do this for more than a few seconds though.

It is totally possible that your problems are electronic too. Do you have a strong and consistent spark ?

Ted
MotoRevive.

__________________
Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.

OK bit of an update....

Went to try again and the fuel overflow pissed out fuel, so 2 things. 1 plenty of fuel getting there, 2 float stuck. The carbs on this are a major pain to remove, they don't seem to fit between the frame and block. Anyway I gave up for the day as I couldn't face it.

Tried again this morning and there was no leak.
Kicked the bike over and she starts but doesn't tick over for more than a few seconds. Can't touch the throttle, just dies straight away.

Idle screw is just touching the mechanism, any more and she won't fire, any less and its not doing anything.

Tried some easy start and it will keep her ticking over, not revving high, just ticking over.

I managed to get a couple of good revs from the throttle but didn't want to do too much.

Just wont tick over, its like it won't rev till its warm but won't run enough to get warm.

Not sure about the mixture screw, don't even know where it is. For those unfamiliar with the Yamaha YDIS carb, its a single carb with extra inlet system, no float bowl on the secondary side, it is fed from the primary. So its not dual carb, more like 1 and a half carbs.

The other issue I have is it is an Italian import (private import) so the engine number doesn't come up on any Yamhaha charts. I am really struggling to find parts like jets etc.

Any advice welcome, I need to use this bike in a few weeks.

TIA

Back to a major carb clean and set. Trying to fix external bits in an ad hoc manner will leave you chasing your tail and drive you crazy - and not fix it.

Go back to the basics - make SURE the carb is RIGHT.
Make SURE the spark is good and strong with a fresh spark plug.
Make SURE there is good compression.
Check the timing!
Then see what happens.

__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com

Is it also worth checking the air filter?

Supermotodave, your profile doesn't say where you're from, but here are a couple of sites that may be useful in identifying your TT600 and for buying new parts:

https://www.fowlersparts.co.uk/brows...aha/bike/tt600

https://en.impex-jp.com/catalogs/moto/yamaha/tt600.html

check the air filter, but unlikely to be the cause


that bike shouldnt have a vaccuum pick up point, but who knows, might be drawing air from somwhere, check that there are no suspect un plugged tubes on carb or manifold


did you try to raise the idle screw?

Is the fuel enrich circuit actually flowing fuel when the knob is pulled? Bike will normally run for a few revolutions when cold and no choke. I would unscrew the starter/ choke knob from the carb and ensure all is working correctly.

Is pilot jet really clean? Even when you think they look clean and you can see through it there can be a layer of old fuel varnish that is very hard to remove out of such a small hole. Many an idle issue on my bikes have been solved by tossing the "cleaned" jet with a new pilot jet !