Mikuni Jet

Mr. Deere · Post by **Mr. Deere** » Fri Sep 21, 2007 4:43 pm

Cant help ya with the test but what you could do to start is get all the correct jetting in the sled. You are going to have to do it anyways might as well do it now to see if thats the problem. If you want i can post up the jets from the fine tune manual for you. BOB

jdcat · Post by **jdcat** » Fri Sep 21, 2007 4:44 pm

Air screw on this mikuni is behind the air box boot.Throttle stop screw near the carb boot. Both on left side of carb.

Mr. Deere · Post by **Mr. Deere** » Fri Sep 21, 2007 4:45 pm

Weird mine are different. BOB

jdcat · Post by **jdcat** » Fri Sep 21, 2007 4:51 pm

Only markings on the carb are MIC 500 61. Not even sure its a VM carb.It does have overflow outlets on top & bottom of carb bowl.

jdcat · Post by **jdcat** » Fri Sep 21, 2007 4:52 pm

Course this is a single 34mm carb.

Mr. Deere · Post by **Mr. Deere** » Fri Sep 21, 2007 4:52 pm

Might not be then. I will get you the jetting and the correct carbs that were supposed to be on it. Let me go get my book. BOB

Mr. Deere · Post by **Mr. Deere** » Fri Sep 21, 2007 4:57 pm

What temps will you be running this sled in above or below zero (Majority) also what Altitude above sea level. BOB

jdcat · Post by **jdcat** » Fri Sep 21, 2007 4:59 pm

Possible somebody stuck a power jet carb on this engine? Dont know if any of the vm carbs had an overflow fitting on the bottom of the carb.I know they had it on top.

Mr. Deere · Post by **Mr. Deere** » Fri Sep 21, 2007 5:06 pm

Well according to my book Your 79 Trailfire would take 1 VM34 NON POWER JET. BOB

jdcat · Post by **jdcat** » Fri Sep 21, 2007 5:31 pm

Already know the main jet is 230 ,pilot 25. This is right. Cut away in the slide may affect idle some, But a 3.0 is richer than a 3.5, Youd think id have to lean out the air screw to use the 3.0. Instead i have to richen it for any idle. Needle jet and all else have to do with 1/4-1/8 throttle & up.Unless im wrong on carb function it should idle with the 230 main & 25 pilot. I Think Danzig is right & im missing a air leak somewhere. Just though i could get the engine to idle,Run it Make sure lower end & crank are ok before putting another 50-60 bucks into the carb.

Mr. Deere · Post by **Mr. Deere** » Fri Sep 21, 2007 5:35 pm

OK anyways I left you a Pm with the Jetting Specs. BOB

Danzig · Post by **Danzig** » Fri Sep 21, 2007 5:57 pm

Go to the FAQ forum and look up pressure testing an engine.

jdcat · Post by **jdcat** » Sun Sep 23, 2007 2:02 pm

Looks like im stuck with the 6F9 jet needle on my trailfire.The 6F27-3 that i need is non-existant, At least a week of searching online hasent panned out.

Mr. Deere · Post by **Mr. Deere** » Sun Sep 23, 2007 4:08 pm

The jet itself is only 6F27 the three is for the clip on the Needle. All you need to look up is 6F27. BOB

That Girl Racing · Post by **That Girl Racing** » Tue Sep 25, 2007 10:59 pm

The biggest mains available from Mikuni are 720s. The aftermarket makes bigger ones. We use around 1080s on our race sleds with EE0 tubes. Peter