What will happen?: Mikuni BS34SS Carb from '84 Kawa GPz 750

[Anonymous]

I've had an "experience" that requires replacing my carbs. Please don't ask...some things are darn near as embarassing as falling over in your own driveway.

The stock carbs on my '81 GS1100E are Mikuni BS34SS, the same as on an '84 Kawaswaki GPz 750. I was able to buy the GPz's carbs on Ebay yesterday for $71.00, including shipping. So, you understand that I'm trying to save some money.

I might be able to recover most of the jets from my now-unusable carbs. So, should I just slap the GPz carbs on my bike and fire it up, or should I bite the bullet at the gitgo and buy all the internal gizmos and set everthing to the stock specs for an '81 GS1100E?

Is there any real chance that the bike will run fairly well after just slapping on the "new" carbs as they are set to the specs of the '84 GPZ 750? Am I looking for bad trouble when I should just do it right?

Hap, this is not an electrical question, but you can offer an opinion (besides why in the heck I'd even try this)...

[Anonymous]

If your bike was running right when your carbs became unusable, be sure the jets in the GPZ carbs are the same size as the jets in the unusable carbs. Needles may need adj. but you will not know for sure, till you try it.

[SqDancerLynn1]

Other than minor differences they are the same carbs

[KEITH KRAUSE]

If the carb bodies are identical, you should be able to transfer everything over. Just be sure to check the float heights and keep records of your mixture screw settings. You may have to fine tune the mixture screws.
Keep each float valve and its seat together as a set. Also each needle jet should stay with its jet needle.

[Anonymous]

But, what will happen?

Yep, they are the same carbs. Yep, things ought to work if I just transfer the innards over carb-by-carb and keep the GS1100 settings.

But, if I just slap it on...what will happen?

[Dink]

You will fry at least one valve. An 1100 needs more fuel then a 750, surprisingly
Dink

[focus frenzy]

also the rack that holds the individual carbs together and the bracket for the choke and throttle cable will need to be used from the 1100

[Anonymous]

Thanks Dink

I didn't know whether it would simply underperform or if something bad would happen. So, if there is a real possibility that something bad will happen (ie: frying a valve), I'll do it right (like we all know we should, but sometimes are tempted to be lazy and/or cheap).

Thanks all for your help.

[KEITH KRAUSE]

Re: But, what will happen?

Yep, they are the same carbs. Yep, things ought to work if I just transfer the innards over carb-by-carb and keep the GS1100 settings.

But, if I just slap it on...what will happen?

There's literally no chance the jetting components are all the same. You'll have to transfer every part and re-adjust the floats.

[Anonymous]

Someone please explain!!!!! Why would a 34 mm Mikuni from a GPZ 750 not flow the same fuel & air as a 34 mm Mukuni from an GS 1100, if it has the same size jets & jet needle? I may could see it if you were talking about a totally different type of carb, but the Makuni carbs on the GPZ 750 & the GS 1100 are the same thing if fitted with the same jets & jet needles, except for the color & the shape of the top that covers the diaphram.

[KEITH KRAUSE]

I'm not sure of your question. Nobody said the carbs wouldn't work. But the jetting components will all have to be transferred.
The carbs are jetted to match the design of the motor.

[Einar J Skog]

Hi


Most likely it will run a bit rich with the kawa jets.
They are smaller in the suzi carbs..