Pods and Aftermarket Exhaust

[bottobot]

And I was wondering how to determine the optimum jetting? I have looked at some jetting kits on ebay and such and I am unsure, other than a subjective ride around test, to know whether I have put the right jets in?

Anybody have an experience with this.

I am currently running a Yoshimura 4-1 and those cone air filters on the carbs.

[MisterCinders]

And I was wondering how to determine the optimum jetting? I have looked at some jetting kits on ebay and such and I am unsure, other than a subjective ride around test, to know whether I have put the right jets in?

Anybody have an experience with this.

I am currently running a Yoshimura 4-1 and those cone air filters on the carbs.

Is this for the 1978 GS 750 in your sig? If so, there is no kit for that bike. Just trial and error.

Which pods are you using?

[Big T]

And I was wondering how to determine the optimum jetting? I have looked at some jetting kits on ebay and such and I am unsure, other than a subjective ride around test, to know whether I have put the right jets in?

Anybody have an experience with this.

I am currently running a Yoshimura 4-1 and those cone air filters on the carbs.

Plug chops - read up on them on Cliff's site

[bottobot]

Hey there,
I have no idea what brand of filter they are but here's a pic of my bike and maybe you can see.

Plug chops? Sounds interesting I'll go on Cliffs site and see what those are.

Thanks guys.

[JimmyR]

It depends how much you want to spend, but Mikuni RS carbs are made exactly for that situation. It would probably be easier to set up a set of RS carbs than older carbs designed to work with an airbox and 4-2 exhaust. They are set up at the factory for pods and a more open exhaust and might not need much tweaking once installed.

[bottobot]

Well my bike is real junker rust bucket so I don't think I am ready to make that kind of upgrade just yet. I'm starting to get some real big plans for this bike and those carbs are right up my alley, which is a bit down the road. Hopefully I don't end up in the ditch before that though... ok this metaphor has run its course :P

Thanks for the tip though, I managed to find some of the RS34-D21-K carbs for 660$ but they are selling elsewhere for up to 825! When I bore out and cafe this bike one day I'll look at getting them.

Hey MrCinders, I found this jetting kit on ebay for $50, looks like I could use it. What do you think?

[gearheadE30]

....why don't you fix the rust and the bits that make it a junker before putting pods on it? It's a lot easier to get it running right if everything else is already good to go.

[bottobot]

The previous owner put those on, him or one of the dozen other people that have owned this bike. I would like to try and move forward with the bike rather than try and put it back to stock since it has an aftermarket header and yoshimura exhaust on it.

I actually like the rust, and may turn this bike into a rat/sleeper race bike down the road. In the meantime do a rebuild and get it running right before I do any performance modifications.

I got a HUGE list of to-do's before I get crazy. Stuff as basic as replacing the head gasket which is leaking oil and fouling my plugs on the daily.

[TheCafeKid]

Can't even begin to jet the bike if it's fouling plugs. Need to take care of the head gasket. And judging from your pic, you need to tear the carbs down and rebuild them too. The spray can isn't going to do it. Read BassCliffs site thoroughly. Do that stuff, otherwise you're compounding your problem and the only "forward" you'll go is pushing the bike to the curb..

[bottobot]

Hi CafeKid,
The carbs are pretty darn clean and seem to working relatively ok. I'm waiting on a gasket kit to arrive. The head gasket is just the beginning! As you can see from the pic, I am just working out in the parking lot of my apartment right now, but I have a workshop that will be up and running soon where I can play with solvents all day long without bothering anyone.

I'm more curious about if there is a way to determine optimum jetting with this set up and what that may be. Any ideas?

[tkent02]

No hell no. Get the Sawzall out, hack away at it first.
It will never run right anyway.

[bottobot]

Hmmm... I knew the bike had to much stuff on it! The swingarm is expendable right? And if I got a newer gsxr front end I could probably get away with only having one front fork

[LeeGS550E]

Hey there,
I have no idea what brand of filter they are but here's a pic of my bike and maybe you can see.

Plug chops? Sounds interesting I'll go on Cliffs site and see what those are.

Thanks guys.

At the very least, if you want to stick with pods, get some K&N's or Unis. You will never get it jetted with those cheap pods. I tried for a short time and quickly realized that once you'd get one part of the rpm's working decent, the other parts of the range would be shot. Those things would make better earings than filters.

[MisterCinders]

Well my bike is real junker rust bucket so I don't think I am ready to make that kind of upgrade just yet. I'm starting to get some real big plans for this bike and those carbs are right up my alley, which is a bit down the road. Hopefully I don't end up in the ditch before that though... ok this metaphor has run its course :P

Thanks for the tip though, I managed to find some of the RS34-D21-K carbs for 660$ but they are selling elsewhere for up to 825! When I bore out and cafe this bike one day I'll look at getting them.

Hey MrCinders, I found this jetting kit on ebay for $50, looks like I could use it. What do you think?

I wouldn't bother with a $50 package that includes:

4 x #100 Main Jets (you already have these stock jets)
4 x #110 Main Jets (unlikely to be big enough)
4 x #120 Main Jets (might work)
4 x #140 Main Jets (probably too big)

The washers in that picture must be for shimming the needle, I guess.

Instead, order three sets of Mikuni main jets in the most likely sizes (maybe 117.5, 120, 122.5) @$1.75 from Z1

For about $25, you'll have some main jets you can actually use. If you need to move up or down a step, you are $7 away from another set of mains.

Z1 also has pilot jets in 17.5 and other sizes, if you want to change that too. Finally, adjusting the needle by one or two clips costs nothing.

[OldVet66]

Unless you have just started a complete tear down to soak those carburetors in a carb dip, you are totally wasting your time with carb cleaner. it will not clean the years of accumulated crud from the passages.