The XT350 thread

[Grreatdog]

Your book is different than my Clymer manual.

[SkidMarx]

Originally Posted by Grreatdog

Your book is different than my Clymer manual.

Mine to.

[Lenz1]

The manual I'm working from is genuine Yamaha for the TT350S. The XT350 has got the same carbies as the TT350 I'm working on even if the jetting is varied slightly. If the Clymer manual gives the correct on-bike fuel height as 6.0mm +/- 0.5mm below the bowl mating surface level then the correct off-bike / bench setting for the float height is 26.0mm +/- 2.5mm above the inverted metal face of the carbie body.

Leave the central "tang" alone and set each float height individually by bending the float plate arms. Use two pairs of pliers as I described earlier. This individual adjustment corrects any dislevellment / height diferences between the twin floats and ensures the float assembly rotates smoothly around the fixed float assembly shaft/pin

Perhaps the Clymer manual lost something in the translation

[Grreatdog]

Originally Posted by Lenz1

The manual I'm working from is genuine Yamaha for the TT350S. ......

In this country XT and TT are two entirely different bikes. The TT here was a competition offroad bike that was not street legal and very different than our XT. We did not get the TT models that are imported to other countries.

Our XT uses a half CV monstrosity of a carb that is EPA jetted so lean the bike will barely run. There is no float height setting in the manual. You have to buy or a make a special Yamatool and adjust the fuel level through the float drain with the carb on the bike and assembled.

It is pure trial and error with each error requiring disassembly and reassembly to test. The slightest error and the bike either leaks fuel or won't run. Trust me, it is a bitch to do.

[SkidMarx]

Originally Posted by kaisan

Yah brand new carb rubbers,Plug is wet with gas,but just doesnt want to fire.Even took the exaust off figured it was pluged.
What else could I check?

Did you put the new rubbers on before or after the carb kit? If after, try putting the stock jets back in. The bike should run OK stock, it will just be lean which it definitely isn't right now.

If you aren't messing with the exhaust, or intake for better flow, the only adjustment really needed to the carb is to the pilot needle so that it will start easy.
Yes, the carb can be jetted to run better, but you need to get it running and then only make one change at a time. To get it running, stock settings should work

also,
It isn't that hard to check the timing so that might be a good place to look next. Carefully remove the stator cover(you may be able to save the gasket since it runs dry). Remove the valve cover. Line up the timing marks per the manual.

Originally Posted by Lenz1

Perhaps the Clymer manual lost something in the translation

Could have. wouldn't be the first thing messed up in the clymer.
Once I finally got mine adjusted, I took a measurement and wrote it down so I wouldn't have to go through it all again if I somehow knocked it out of adjustment.

[NordieBoy]

Originally Posted by Grreatdog

In this country XT and TT are two entirely different bikes. The TT here was a competition offroad bike that was not street legal and very different than our XT. We did not get the TT models that are imported to other countries.

The XT and TT here are also two entirely different bikes.

As enduros sometimes crossed public roads, most enduro bikes were road legal.

Even the IT490 and friends.

[Earthscape]

Originally Posted by Lenz1

The manual advises the primary carbie be removed from the engine and inverted with the bowl removed prior to checking / adjustment of the float height (hard to measure the float heights without the bowl off) The implied outcome from the manual is that setting the float height correctly will produce the required fuel height of 6mm +/- 0.5mm below the metal face of the carbie body.

This is a genuinely serious question (not directed at anyone in particular). Are there places where people use "official slang" to call a carburetor a "carbie"? I know different countries spell "carburetor" slightly differently, but I haven't seen anything indicating a large group or area consistently use this term. I ask because I think it will bother me slightly less if I knew it was generally accepted in some areas the way "carb" is often used. Is this common in Australia or Europe?
Again, not trying to poke a hornets' nest, just would like to know.

[LanaTheGreat]

The original toolkit for the Yamaha XT350. The one at the top is from my 2003 XT350, and the one at the bottom is from my wife's 1994 XT350.

It has a total of 13 parts, counting the bag as a part.

[Lenz1]

Originally Posted by Grreatdog

In this country XT and TT are two entirely different bikes. The TT here was a competition offroad bike that was not street legal and very different than our XT. We did not get the TT models that are imported to other countries.

Our XT uses a half CV monstrosity of a carb that is EPA jetted so lean the bike will barely run. There is no float height setting in the manual. You have to buy or a make a special Yamatool and adjust the fuel level through the float drain with the carb on the bike and assembled.

It is pure trial and error with each error requiring disassembly and reassembly to test. The slightest error and the bike either leaks fuel or won't run. Trust me, it is a bitch to do.

My understanding is the XT350 and TT350 share the same engine and carbies with variations in jetting, don't know about the cams but I suspect differences in valve timing also.

If the Clymer manual has the fuel height at 6.0mm +/- 0.5mm then the float height setting for a bench adjustment is as I've suggested. Please yourself on the bench adjustment procedure I've outlined for the twin floats. Maybe there's something to that old saying about Great Dogs and new tricks

[duneracerweston]

Alright, i got a few questions for you XT and TT guys on here. i dont have a XT or a TT but i building a hybrid of sorts, im building a yfm350 (warrior) motor and using a XT head, i know its not a direct fit and will take a crap load of modifying to fit, thats not what my question is. i have two actually and they are as follows.

1. Can you get oversized valves for these motors? this head i have has bent intake valves and was hoping to oversize them.

2. can you get i higher then 9.2:1 compression? because thats the highest comp ive found, i was hoping for a 11:1 or maybe even a 12:1 which would put this 374cc hybrid to about 12.9:1 which is about the comp im wanting to run. (plan on running 110 VP race fuel and a single carb)

any help would be awesome!

BTW my names Weston, nice to meet the inmates.

[kwakbiker]

Welcome along, cant really help with the tech Q's but just wondering why your not using Warrior parts or RD350 stuff?

[duneracerweston]

Well, the warrior head is a stuffed up 2 valve that only builds 17 horses stock and if you modify it to the hilt, 35hp is about all the head design will produce, so im using the xt because its a 4valve, and from factory its about 27 hp.

Im hoping to have it finished before March because thats when the mx series starts. I have a regular warrior motor I built in case the xt hybrid didn't work out. So its a spare motor at the moment. But in the little info I can find about people modifying these most complain about small valves so thats why I asked about the oversize valves. The head will be ported regardless, so I guess that if f there's no alternative valve options I use the STD valves.

[NordieBoy]

Originally Posted by duneracerweston

Well, the warrior head is a stuffed up 2 valve that only builds 17 horses stock and if you modify it to the hilt, 35hp is about all the head design will produce, so im using the xt because its a 4valve, and from factory its about 27 hp.

Maybe 27 at the crank.

A WebCam would help matters too.

[duneracerweston]

Originally Posted by NordieBoy

Maybe 27 at the crank.

A WebCam would help matters too.

both stock numbers were at the crank

was planning on using the megacycle cams not sure which i will sue considering its a stroker motor compaired to the stock xt motor.

[tellicotom]

I currently ride a 2000 Yamaha XT350 as a DualSport. Love the Bike except....it's a Kick start and VERYYYYYYY cold-blooded!

I've ridden both off-pavement and like the Power of the XT vs the KLX, but HATE the kick start. Also, the air-cooled seems to be a down-side of the XT in the heat on single track.

I have an opportunity to pickup a KLX250 at a decent price and I'm considering it. But, I need a little help making the final decision............

I've done the +/- thing and here is what I have.

I like the Yami height wise and performace wise over the Kawai, but it is hard starting and Always a kick starter!

The Kawi is 7 years newer and has ~ 8,000 less miles.

The Kawi was ridden by a 250 lb man off-road for ~ 1500 to 1800 miles. Nornal scuff marks, but nothing beyond cosmetic that I can tell.

I know...why decide...have both!

Whatda you all think?


Thanks,
TellicoTom