tri-z 85 carb

[steven 250sx]

what are the factory settings on the carb i looked through the manual and can't find anything like the idle screw air pilot screw that good stuff

[03 ORANGE SHEE]

470 main
45 pilot
float height 31.3mm.
needle 3rd. down from top
air screw 1 turn out

[Bryan Raffa]

you need to look at the slide and needle to see what you have

the 85 had
470/45/1.0 turns P.2 needle and a 2.0 slide

the 86 had
320/35/2.0 turns P.4 needle and a 3.0 slide

depending on what needle and slide you have you can tell the year of the carb and jet accordingly

[steven 250sx]

wow thxs guys that helps alot

[ColeTrickle]

you need to look at the slide and needle to see what you have

the 85 had
470/45/1.0 turns P.2 needle and a 2.0 slide

the 86 had
320/35/2.0 turns P.4 needle and a 3.0 slide

depending on what needle and slide you have you can tell the year of the carb and jet accordingly

I never realized that 85 and 86 had different carb settings so I started looking at my carbs. I've only been able to get my rig to run on a 340 main. Now I see I've been running a mixture of 85 and 86 carb parts. The needle jet I had in my 86 carb is Q-5, 45 pilot, 6N3-3 needle and 340 main. These pictures show the 2 different needle jets and the 2 carbs. Which carb works better? Also the 85 carb has a main air hose fitting. Does this hose go to the air boot? The 86 doesn't have this fitting. On the intake side of the carb there is a brass ball plugging the hole that looks like it would feed that main air hose passage way. Should this be there? My plan is to get the 85 carb set up stock and go from there. The 85 carb seems to have a bigger bore and also has richer jetting, should be better right?

ok. editing post. Just put the 85 carb together with all 85 stock parts. Runs best with 470 main and all the other adjustments in the stock settings. My next plan is to put an 86 carb together with stock settings and try that. Then I'll post up what I felt the differences were.

[Bryan Raffa]

I never realized that 85 and 86 had different carb settings so I started looking at my carbs. I've only been able to get my rig to run on a 340 main. Now I see I've been running a mixture of 85 and 86 carb parts. The needle jet I had in my 86 carb is Q-5, 45 pilot, 6N3-3 needle and 340 main. These pictures show the 2 different needle jets and the 2 carbs. Which carb works better? Also the 85 carb has a main air hose fitting. Does this hose go to the air boot? The 86 doesn't have this fitting. On the intake side of the carb there is a brass ball plugging the hole that looks like it would feed that main air hose passage way. Should this be there? My plan is to get the 85 carb set up stock and go from there. The 85 carb seems to have a bigger bore and also has richer jetting, should be better right?

ok. editing post. Just put the 85 carb together with all 85 stock parts. Runs best with 470 main and all the other adjustments in the stock settings. My next plan is to put an 86 carb together with stock settings and try that. Then I'll post up what I felt the differences were.

Thats cool you have both to try LET US KNOW!!

the 86 didnt have that hose to breather tube..also the 86 intake tube was bigger at the bottom

[Tri-ZNate]

Why such a large variation in jetting? Arent they the same basic engine?

[Bryan Raffa]

Yes but improvements came in 86 there both Vm32ss carbs


Any one know the differences in the cylinders? Or how to tell them apart? Was there a difference? I thought there was a change to the intake..

[Tri-ZNate]

Have a chance to try the '86 out? I'm getting an '86 carb for my '85 Z and I'm thinking I'll need all new jets to fit to the '85 spec.

[ColeTrickle]

I'm still messing with this. So far the stock 85 carb with the stock jetting listed above runs good in bottom and mid but is lacking up top. The 86 carb with stock jetting runs good on top but bad on bottom. I've gone up and down with the main jet sizes on the 85 and have not got it much better. I went with the 85 low speed settings and the 340 main on the 86 and that has worked the best so far. I think I may have some other issues with the cylinder and piston that may have been caused by being too lean on top with the 85 carb and going out at night when it was around 20 degrees. Will get back to this soon.

[Tri-ZNate]

Well I got my '86 carb thrown on tonight, went to get a '85 rebuild kit and turns out they are untouchable . SO I took the main out of my old '85 carb (490) the old pilot jet was trash (stripped out) so i went to the bike shop and they didnt have anything close to the 45 pilot so i used the 55 pilot that was in there (yeah I dont understand that one).

Runs DAMN good but on the idle circuit it will surge and die after 10-15 seconds and I have only my idle adjustment, A/F screw doesnt seem to do anything. I have my chopped plug here and it looks a little black so i think I need to order a 45 main and go from there

[DeePa]

hope that carb works out well for you nate...

mike

[Tri-ZNate]

I hope so too Mike . Thanks again

[Tri-ZNate]

Ok I got my Z carb dialed in for the most part.

Stock '86 carb on a '85
I only changed Jets, did not mess with the needle or clip
55 pilot with a 490 main
Boyseen Power reeds and Dg pipe

Pilot is carmel brown and the main is dark, but not cutting out on top which is what I wanted it. Just a little update to the thread