36mm Slingshot carbs on a GS1000E

[Diamondj]

Hi!

I searched through the previous posts but I didn't see this covered anywhere. Is anyone here running 36mm Slingshot (88 GSXR750) carbs on their GS1000? I have a '78 GS1000E and I have a set of 36mm slingshot carbs that I would like to try on this bike. I also plan on running K&N pod filters and a Supertrapp exhaust. If you are running the 36mm slingshots on your GS1000 - what jetting and needle position are you using? How well does it run? Did you have to make any other modifications to install the carbs (manifolds, etc...)?

Thanks!

Jim

 

[Hoomgar]

I am pretty sure that the E model had the same size carbs and intakes that the straight C did in 78. If thats the case, they are going to be too big. You may need to get a cylinder and head off of an 80 model to get the larger intakes. They came with 34mmcv carbs. The 78 came with vm26mm carbs.

I could also be wrong but that is my understanding.

 

[Diamondj]

Hey Mark!

Yep - mine has the 26mm carbs. So add a late model 8 valve head to my shopping list.....

Thanks!

Jim

 

[Hoomgar]

Hey Mark!

Yep - mine has the 26mm carbs. So add a late model 8 valve head to my shopping list.....

Thanks!

Jim

You will need the block to Jim. It has different bolt pattern.

See the bolt in this pic: http://home.ptd.net/~megabyte/progess10.html

 

[Diamondj]

Hey again Mark!

Would the GS1100 block be the same as the late model 1000 block? I have a 73mm bore 1100 block and 4 valve head but I am not sure if they would bolt up to the crankcase or not. Plus isn't the stroke longer on the 1100 as well? So I would have to change either the rods or the cranks too... Okay this is getting complicated!! ;-)

Thanks!

Jim

 

[Hoomgar]

Yes I would keep it simple. I know you can put a set of 29mm smooth bores on it but other than that if you jet it correctly the 26mm carbs work well as they rely on increased velocity to do the job which they do well.

I just think that the 36mm will be too much anyway unless your going to bore out to a larger bore maybe? I also don't know about mixing the 1100 block with the 1000 lower end.

Hopefully someone will post in here soon that knows what they are talking about for you

I know my 78 1000 pulled like a freight train with the stock configuration when it was setup right and had no trouble at all burying it's red line and beyond in final gear in very short time. They are incredible engines and the designers kind of figured out what worked best many years ago. We just love to play with them

Mine is going to be an 1100 when I am done with 34mmcv's on it. I hope it works out as well as I am hoping

 

[Anonymous]

You will need the block to Jim. It has different bolt pattern.

Hi Hoomgar. This is not strictly true. I have found that the later head will run on the earlier block (and vice versa) with no problems. The extra bolt is there to stop gasket weeps which originally occured due to owners not retorqueing their heads correctly at the first service.

Obviously the earlier heads/blocks still have this potential "problem", as does a late head on an early block, but if you torque the head down correctly, then retorque it at 500 miles you will be fine.

 

[Anonymous]

Yes I would keep it simple. I know you can put a set of 29mm smooth bores on it but other than that if you jet it correctly the 26mm carbs work well as they rely on increased velocity to do the job which they do well.

I just think that the 36mm will be too much anyway unless your going to bore out to a larger bore maybe? I also don't know about mixing the 1100 block with the 1000 lower end.

Hopefully someone will post in here soon that knows what they are talking about for you

I agree. The GS1000 works well with 26mm slides. The 28mm carbs as fitted to UK bikes are a bit better, as are 29mm smoothies, if you can find any that aren't worn out.
With CV's, 34mm is about equivalent in flow to 28mm slide due to the obstruction caused by the throttle butterfly, but a 36mm CV is too big IMHO for a stock GS1000. I've run the 1085 wiseco kit with stock 28mm carbs and airbox, with a V&H pipe and the carbs etc do not restrict the engine much, if at all.

 

[Anonymous]

your head trouble

your head trouble

find a gs1000g head, it will bolt right on has the bigger intakes and it has bigger valves.

 

[Anonymous]

Re: your head trouble

Re: your head trouble

find a gs1000g head, it will bolt right on has the bigger intakes and it has bigger valves.

Hmm, no, all GS1000's from earliest to latest had same valves.