Rejetting for Straight Pipes

[crash-harris]

Ok, I got the '82 GS450L running and I fried the left ignition coil so those are due for replacement. Also welded up some new exhaust pipes. When I got it running I was using a cream soda bottle for a gas tank and no intake so the bike would die if it wasn't choked. But I'm going to start working on the airbox now and get it ready to go on the carbs once they are cleaned up.

My question is, would I still have to get the Dynojet kit if I use the stock setup but with open pipes (no mufflers or the crossover pipe)? Or can I get away with some carb tuning? Carbs still need dipped and new gaskets.

[Dave8338]

With just the pipes, it is likely that bumping the jet needles will work for you.

[crash-harris]

That's a big relief, thanks!

[crash-harris]

Just got to thinking...shouldn't I need to enrich the mixture for straight pipes? Or lean it? (Jets in/out?)

[almarconi]

With stock pipe and airbox, these bikes were jetted lean from the factory. I would imagine that adding a less restrictive exhaust would require you to richen things up not make it more lean. You'll have to get it put back together, run it and see where you are.

[crash-harris]

Thanks. Going to swing by the boneyard today and see if I can't get an airbox and ignitoin coils and I'll see where she stands when I get back from Cinci this weekend.

[Larry D]

Thanks. Going to swing by the boneyard today and see if I can't get an airbox and ignitoin coils and I'll see where she stands when I get back from Cinci this weekend.

Boneyard ??? Where is there a boneyard in Cincy ?

I grew up in Hillsboro, OH...btw. Say hello if you go home on SR50.

[crash-harris]

Wow, somehow I missed your post! The boneyard I was talking about is the one off US23 around Chillicothe here. And unfortunatly I didn't take 50, 270 (the barrel loop) to 71 and back down on 35.

How far down on 50 are you?

Anywho, I'm looking for the write-up on how to adjust the jet needles. I know it's around here somewhere but I can't find it? I'm thinking that I need to drill the caps on the carbs that are between them and the engine right?

[almarconi]

Anywho, I'm looking for the write-up on how to adjust the jet needles. I know it's around here somewhere but I can't find it? I'm thinking that I need to drill the caps on the carbs that are between them and the engine right?

If the jets inside the carburetor are stock, no amount of adjusting the mixture screws is going to compensate for an open exhaust. You need to open the carbs and figure out what jets are in there now. If you are using the stock airbox, you will need to go several sizes larger on the main jets and more than likely shim your needles. It may also be necessary to go up one size on your pilot jet depending on how the bike runs. You may also need to adjust the fuel level to compensate.

[crash-harris]

I don't remember, but can I get jets from Z1?

[67fire]

Have you tried the Dealership for jets? I got two sets of 4 in the past few weeks from the one that is here.

Eric

[crash-harris]

No dealership here. Nthin' but a Harley store.

[chef1366]

With a straight pipe I'd go up two sizes on the main jet and shim the jet needle.
Z1 has jets but I buy locally or from Denniskirk.com.

[crash-harris]

I may have to go with Dennis Kirk anyway. I went on Z1 and couldn't find jets in the carbs section.

[crash-harris]

Can't find jets on denniskirk.com either for an '82 GS450LZ?