Mikuni set-up

[Sheep]

Guys,having just bought a bike with some nice RS flatsides i find it disappointing that they are way to big for the bike.My friend used to have a Katana 1216 with Mikunis and he loved them.The thing is i would like to have these carbs on the bike and after doing a lot of reading it seems they are popular.

The ones i have are 40's and not 36's as i believe they are supposed to be.My main question is can i jet them down to perform like the 36's or will the bore size still cause me issues??I do not really want to buy a new set at £800 or so and ideally i do not want to go back to the CV's unless i have to.It seems a shame to have these attached to the motor and not get the best out of them.

The bike does run (i havn't got it on the road yet) and apparently was ran like this by the previous two owners!! but the exhaust is rich and tends to bog when revved too quickly which in turm makes it cough a quick short flame.I do have new Taylor leads,plugs and Dyna coils fitted btw.

Is down jetting possible to get a useable set of carbs or not?Any help appreciated.

[markfoggy]

I think you're gonna find them just about unuseable on the road. Big mouths like that are great for top end performance and you could probably get a setting that would seem to work on a Dyno and would probably be great on their day at the Manx. Rest of the time I reckon that you'll never get any midrange out of them and they'll be a right pain in the arse.

Good news though is people always think bigger is better, so they'll probably fly on the site beginning with e. 40mms aren't that common.

Get 'em sold and treat yourself to a new set of 36mm's. You'll also be amazed what people will pay for carbs on auction sites. We've got into the habit of regularly replacing sets (like nearly every year) as people seem to assume that they cost a fortune and haven't done their research.

I'm basing this on our experience with 1260 EFE lumps for prolonged race use. We can't fit flatties as the regs don't allow, but for most circuits we get better lap times out of 33mm Keihins than the 36mm's which are a lot more difficult to set up. The riders like the unrestricted power from the bigger bodies as overtakes are easier, but the 'ickle ones deliiver the lap-times.

[Sheep]

Oh cool....thats interesting.Like you say,some people think bigger is better.Thank you.

[KATANAMANGLER]

Hi what is the engine you have in your bike?

[Sheep]

Hi mate,as far as i am aware,bearing in mind i didn't go as far as strip the barrels,block etc it is standard with the exception of the head having had a little tickle to improve flow.When i was talking to a local parts supplier i mentioned the carbs and he said it could be a big bore motor but as far as i know it is not and i bought it under the assumption it was not anything larger than standard.Could i tell visually or would i need to strip to confirm?....(the latter i guess).I am surprised the last couple of owners used it as it is.Having said that the last owner is into drag Gsxr's now and you would have thought he would have known this.He was a decent guy and i still have a lot to learn so i never questioned anything really.

[KATANAMANGLER]

So it's a GSXR 1100 motor?

[Sheep]

Sorry mate,i forgot to add,its an air cooled GSX 1135 motor.circa 1984