Gs1100g mikuni needle jet help

[Guest]

I'm looking to replace my needle and needle jet for my 1982 GS100GK and can't find one available. The number on the jet is 338PX-3. Anyone know of a cross reference?

[JTGS850GL]

I'm looking to replace my needle and needle jet for my 1982 GS100GK and can't find one available. The number on the jet is 338PX-3. Anyone know of a cross reference?

That doesn't look like a Mikuni Needle Jet part number. Are you sure it's a Mikuni jet? I don't see the Mikuni trade marked square in a square symbol. Are yo looking for a stock needle and jet? If so, the stock numbers should be 5D58 for the jet and X-3 for the needle.

[Detbjr]

Not sure - the carbs are pretty mangled up so it might not be stock. I was looking for stock replacements. On jets r us I saw different series numbers. They didn't have x-3. Nor 5d58. Anyone know where I can get stock needle and needle jet that will work on this bike?

[JTGS850GL]

The needles and needle jets are no longer available. Used is your only option. I may have a complete set at the house. Do you need just one carb or jets for all 4?

I also have a completely rebuilt set of 1100gk carbs I can part with. All screws replaced with SS cap screws. PM me if you're interested.

[Detbjr]

Here's a link to place called nichecycle supply - numbers are closest I've found - 338-x2 and 5d59. Also has main and pilot jets that appear a bit smaller(?) 100 and 47.5. Would this work?

[Detbjr]

Here's the link http://www.nichecycle.com/ncs/catego...it-by-ncs.html

[JTGS850GL]

You need to have the correct jets. Are you running stock exhaust and air box?

[Detbjr]

Stock air box and a four into one exhaust

[JTGS850GL]

Stock jets would work just fine. Maybe a little richer on the main and raising the needle a tad would help. You're looking for 115 main jet and a 40 pilot. Both are readily available. Suggest getting only genuine Mikuni jets. Aftermarkets have been hit and miss. Keep looking for 5D58 needle jets.

[Detbjr]

Ok - the bike runs like crap. I assumed the jets were stock but apparently it had 338-X1 needle jet, 110 main, 45 pilot. Seemed to run rich - when hot if throttle is twisted wide open it stumbles through about 3k. Then it revs up toward red line but backfires. Smelled rich - unburned gas. When I pulled the rack off the engine the I could see the intake ports were whet - especially middle two cyls.

[JTGS850GL]

Those carbs are more than likely from an 82 1100EZ 16V engine. Someone probably swapped the carbs thinking that all 1100 used the same carbs. Your carbs probably have a 1.2mm main air jet while the correct main air jet for an 1100G/GK would be a 1.7mm. The bad news is that the main air jets are not easily replaced and there are no replacement jets available from Mikuni or anyone else that I'm aware of. Not sure what jetting changes would allow you to run those on an 8V 1100GK engine. Maybe chef can chime in and give you a possible alternative setup. If you can't find a good way to use those carbs, I may still be able to help. I do have a completely rebuilt set of 1100GK carbs at the house that I can let go using your set as partial trade. PM me if you're interested.

[Detbjr]

Which is the main air jet?

[Detbjr]

If they aren't the screw in jets on the back of the carb could these be drilled out?

[JTGS850GL]

Which is the main air jet?

If they aren't the screw in jets on the back of the carb could these be drilled out?

The main air jet is the jet on the front right on the air filter side. It's located directly across from the pilot air jet that is a brass screw in jet. The main air jet is a pressed fit brass jet and not easily removed. It can be drilled out to the 1.7mm size but be VERY careful if you attempt it. Breaking a drill bit off inside will make for a very bad day. If you have some fractional mm drill bits you can verify the jet size by inserting a 1.2mm bit and seeing if it slides in with a fair amount of resistance. The correct jet will accept a 1.6mm bit with ease and barely allow a 1.7mm bit to twist in depending on how accurate your bits are.

[Detbjr]

My local tool supplier has inch fractional sizes. 1.6mm would be 0.06299. The next size up would be a 52 @ .0635. For reference a 1.7 would be 0.06692. My thought is to go smaller. I'd be using a bench top drill press.