Stock main jet 85 tri Z

[84250r]

Anybody know what the stock main jet is on a 1985 tri z is? Also where to get a rebuild kit for this tri z carb? Thanks.

[whiteman350x]

Stock main is 470.

[03 ORANGE SHEE]

thats true ,but at my elevation 1000ft. in va.,my 85 wont run at w.o.t. at anything larger than a 280!! and this 85z is all stock!!!mine bogs down with a 470.

[84250r]

Thanks,,You guys know where they sell carb rebuild kits for the tri z?

[03 ORANGE SHEE]

try bikebandit.com ,or dennis kirk

[84250r]

try bikebandit.com ,or dennis kirk


Thanks,but i tried both and couldnt find anything.

Anyone else have an idea? :?

[TimSr]

Youre best off to replace the individual part that is broken. There arent really any parts to wear out or go bad other than the float needle, and its easy enough to check.

[IneedAnATV]

That's correct, for the 470 main jet. I tried every place possible on the internet, and had no luck finding a carb rebuild kit as well. The Yamaha dealers can get the parts that are needed, thats the route I went atleast. The Mikuni site has individual parts as well. Good luck with it.

[84250r]

Ok,well im going to be picking up a service manual. Then after that i will start to take it apart and fix what needs to be fixed. I never knew how are hard it was to find parts for the Z untill now,and its only been one day,LOL.

[twgranger]

Their are 2 different size main jets for the tri-z. The S model and N model. 470 for the N and 360 for the S model

[84250r]

Their are 2 different size main jets for the tri-z. The S model and N model. 470 for the N and 360 for the S model


Huh? What model do i have,would it say it somwhere? Whats the difference?

[TimSr]

The 85 is a 470.

[Darius1502]

The S model is the 86 Z.....thats all.

Here is a pic of one...since I have not posted in a while!!

[twgranger]

The S model is the 86 Z.....thats all.

Here is a pic of one...since I have not posted in a while!!That's funny mine says (S) on the frame buy the handle bars and mine is a 85. With a 360 main jet in it. ;)

[84250r]

Well guys I took the carb apart and found out that i have a 440 main jet. That seems to lean for my kind of conditions. If its colder outside for a 2 stroke,arent you suppose to lean it out more or richin it up?

[84250r]

The S model is the 86 Z.....thats all.

Here is a pic of one...since I have not posted in a while!!That's funny mine says (S) on the frame buy the handle bars and mine is a 85. With a 360 main jet in it. ;)

I looked on the steering stem(goose neck) of the frame,and didnt find anything that said it was an N or S model. Strange that your says S model,and your being a 85 model. Any way you could have a different frame?

[Tri-Z Pilot]

Yeah, maybe twgranger has an 86 frame, and 84250r, you should richen up your jetting for the winter.

[TimSr]

There is no hard fast rule about how much to change jetting for specifics conditions, and hardware, whether it be temperature changes or a new pipe. In general, in cold weather bikes run much richer than normal when they are first (cold) started, then when they reach normal temp, they run leaner than normal. I would never ever just automatically change a jet because of a weather change or any other chnage without first having done some plug ckecks to see if its warranted, unless youve been through a couple of winters and know your machines individual "personality".

[84250r]

There is no hard fast rule about how much to change jetting for specifics conditions, and hardware, whether it be temperature changes or a new pipe. In general, in cold weather bikes run much richer than normal when they are first (cold) started, then when they reach normal temp, they run leaner than normal. I would never ever just automatically change a jet because of a weather change or any other chnage without first having done some plug ckecks to see if its warranted, unless youve been through a couple of winters and know your machines individual "personality".

Don't you think thats a big jump from a 470 to a 440? I checked the pilot its stock #45.

[TimSr]

Not really. Many many factors affect carburetion and I wouldnt consider that change to be out of the realm of reality, even on a stock bike. Yamaha changed it to a 360 in 86 with little chnage in factors that affect carburetion. Plug checks are the only way to know.

[84250r]

Ok,well I thought about just going back to stock main(470) with new plug and then check. Then go from there. Instead of running the 440 main.

[IneedAnATV]

That looks to be your best bet at this point in time. Keep us informed.

[84250r]

Another question is,have any of you tri-z guy's gone from a #45 pilot jet to a #52?