wow other forums are absolutely no help, i'll try here ttr90 engine problem

[derekhonda]

Sorry guys, i tried going to a ttr forum to get help cause all it seems like I am doing here is asking questions and not contributing much, just real busy lately.

Anyways here was my post there, if you got any solutions i'd love to hear it.

Whats up guys, new to this forum. Im 22, this bike was my little brothers and he (or the parents) bought it for him in 02 and he rode it about 3 times and had one tiny crash and gave it up. I basically took it over and used it just to mess around in the backyard and when we were camping. It isn't modded at all, but while I was away at college it sat in the garage and never got started.

Anyways, im fairly handy, I've been riding fourwheelers and dirtbikes forever but this terd has me stumped. I changed oil, air filter, spark plug, flushed gas tank, pulled carb and cleaned it, put new pilot and main in it, soaked carb in gas over night, cleaned carb again, and put it all together and now when i start it it will either immediately die or else run real crappy.

Plug is dark (only on the tip) and i reeks of gas after is starts and dies. It was leaking gas out of the over flow but i tested the floats and they still float, pin is straight, so i just pushed the little piece that sits between the float and the float bobber (no idea what its called, looks like a horizontal "T") up a little bit so it would sit higher and thus lower the heigth the floats had to go up before it shut off the fuel (no idea if that made any sense)

Im thinking that is probably the main problem but I have no idea where to start fixing it. right now it seems like its a trade off have it run crappy and leak gas or have it not run at all and not leak.

Any ideas?

Thanks!

[Ruby Soho]

the way it runs it sounds like it could have a vacuum leak, because delivering the fuel doesn't seem to be a problem, but getting it does.

[krt400ex]

its obviously getting flooded out somewheres if it reeks of fuel. i dont know too much about floats though...i try to leave them well enough alone.

did you mistakenly buy different sized jets maybe?

[derekhonda]

Nah its exactly the same size, which is stock.

I just disconnected everything from the carb except the throttle cable and then worked the throttle. On my 400 fuel will squirt almost like a squirt gun. It doesn't to it on this...so is it just not getting the fuel and thus making it run crappy? Explain more on the vaccuum leak what could be some symptoms. Thanks guys,.

[krt400ex]

your 400 carb squirts fuel cuz it has an accelerator pump. idk if the ttr90 has one of those...if it doenst that is why it doesnt squirt

[Ruby Soho]

Originally posted by derekhonda
Nah its exactly the same size, which is stock.

I just disconnected everything from the carb except the throttle cable and then worked the throttle. On my 400 fuel will squirt almost like a squirt gun. It doesn't to it on this...so is it just not getting the fuel and thus making it run crappy? Explain more on the vaccuum leak what could be some symptoms. Thanks guys,.

basically, if the engine gets intake ANY where besides the manifold and carb, it will run like you explain. if you can get it to idle for alittle
squirt a fluid around the manifold area and such, if it bubbles and such it will be proof of a leak, a worn gasket etc.. could cause this

[derekhonda]

ok ruby, thanks for explaining. as for your other question no it doesnt really smoke. I think im gonna go strip it down one more time and clean it all out and restart the process.

[SRH]

i beleive there is a hole that runs through the back of the carb where the airboot slides on ,that hole runs inside the carb through the whole for the main and into the pilot, if i had to guess either that hole is plugged in the carb or you didnt clean your pilot jet good enough, especially if it sat with gas in the carb, check your intake valve while your at it, also the chokes sometimes get varnish where they drop in and it may be open right now so thats another thing to check


i would say you have a carb issue, as far as your float put a piece of gas line on the carb and blow and as you blow tip the carb and see when it shuts off


also did you completely dissassemble the carb when you cleaned it, the valve for the float something will get alot of gunk and hold it open a bit

[SRH]

oh yeah , you did put a new plug in right, after they foul once theyll never run right on th at plug, put another plug in and run it

[rollie]

That is litterally exactly what was happening to my 110 this weekend when i brought it home


The kid didnt start it for a year, it needed everything you metioned, a new plug, valve adjustment, and the carb was so gummed it it needed a new one, there only $100 though, now it runs perfect

deff sounds like carb problems, call up yopur yamaha dealer i bet a carb is around $100 and it will run perfect and you'll be back in business

[derekhonda]

Originally posted by SRH
i beleive there is a hole that runs through the back of the carb where the airboot slides on ,that hole runs inside the carb through the whole for the main and into the pilot, if i had to guess either that hole is plugged in the carb or you didnt clean your pilot jet good enough, especially if it sat with gas in the carb, check your intake valve while your at it, also the chokes sometimes get varnish where they drop in and it may be open right now so thats another thing to check


i would say you have a carb issue, as far as your float put a piece of gas line on the carb and blow and as you blow tip the carb and see when it shuts off


also did you completely dissassemble the carb when you cleaned it, the valve for the float something will get alot of gunk and hold it open a bit

I've been over the carb twice and it actually has a new pilot and main so they can't be clogged. As for the little hole I'll have to go and look at the carb im not really sure what you are talking about there.

And yeah I have been through it twice, completely disassembled.

I didn't get to cleaning out the carb this weekend had a little too much fun on this.