GS thou carbs

[Anonymous]

Does anybody know if 28mm slide carbies off a GS 1000S will fit directly onto my '78 GS 1000E.

Also, will it be worth the bother?
The bike is completely standard -even exhausts- and has seamless and torquey spread of power that I wouldn't want to spoil. Course, I could always put the originals back on but I would have spent the money by then!

I picked up an after market Yoshimura exhaust from a workmate for the GS. Nothing trick, looks like a mass-produced 4-1. Does anyone know about these? Probably at least 10 yrs old. Is it worth putting it on? S'pose I'll have to rejet the carbs?

I compression tested the cylinders recently and they all read around 140psi. The spec says they should be around 160-165. When I put a drop of oil into the cylinders they readings went up to 165. Is it worth putting new piston rings in? It uses no oil at all.
Thanks...

 

[saaz]

The 28mm carbs should bolt straight on and the tuning pretty close. I put some 28mm Kawa 9 carbs on my 78 GS no problems, but I did quite a few other mods as well so I don't know what advantage you will get in standard tune.

The original pipes are quite restrictive, so a decent pipe will help things along, and also take advantage of bigger carbs. A yoshi pipe should be ok, retuning is a matter of seeing how it goes. If you don't put pod filters on it may be pretty close jetting wise.

 

[Don Lobacz]

I have a 79 GS1000E and the change to 28mm carbs won't make much of a difference at all (I tried, too), especially if you are presently happy with the overall power. I even had 29mm smoothbores on it and didn't feel that much difference. The stock 26mm carbs really are excellent all-round carbs.

140psi compression is great - don't mess with it. Just ride it and enjoy! I put 80,000 miles on mine before I put a 1055cc kit in it and freshened the top end (decarbon valves/combustion chamber, lap valves, gaskets/seals).

I put the Yosh pipe on my bike in the mid-80s (it is visible on my fuzzy bike in the avatar). Yoshimura rejetting consisted of one size up on the mains and raising the needle one notch. It is actually a very quiet pipe that works very well. The centerstand needs to be removed and a 6 inch piece of frame on the right side (under the passenger footpeg) needs to be cut off (it can be rewelded later, but may never look as good). The header is a lot lighter than the stock pipes, and that is it's main advantage. I feel that the stock exhaust flows very nicely and you won't need the header's higher flow rate until the motor flows considerably more air (bigger carbs, pistons, cams, headwork). IMHO.

 

[Anonymous]

Thanks Saaz and Dan!

It's nice to know there are people out there who share my love of the fine ol' air cooled beast! Seems like you guys have been a long way with your bikes. Spose I'll keep mine forever, it's such a joy!
Thanks for the advice.
I think you're right Dan - save my coin and spend it on fuel! Costs US$ 5.50/gallon here in U.K.
The bike performs so well standard it seems a shame to mess with it. Or better to spend some cash on the suspension. It still wears the original shocks!! Still see off the mummies boys on their plastic fantastics though. Can be bit hairy though, going past them on the bends with the pegs scraping and the whole thing wobbling. Hugely entertaining nonetheless!

 

[Anonymous]

Sorry Don.....I am a dozy Halfwitt! He he!