Boring out my 26mm mikuni carbs to 29mm

[Guest]

I have read in my performance Suzuki gs manual that this can be done. Has anyone on here done this?

[azr]

A friend has 26mm's bored out to 28mms on his 79' 1000S. He bought the bike that way though. Looking at them all that seemed to be changed was the intake diameter, no internal changes that I could tell. I'm really not sure if this is an improvement though, the true 29mm smoothbores have a lot of internal changes. There is a company in the states that will aprently change you 26mm's into 29mm but I'd be curious what all is done.

[wildeye]

hi look at this MAXI-BORE Carburetor Carb Boring Service on e-bay ,251108925818 , they say it better them 29s , I been wounding about it ,

[blowerbike]

damn!
monty cambell is still at it...hehehe
he was/is the "X pipe" guy.
his stuff was never a big seller..."1980's"
oh the memories

[Warren]

Here some info on this that I found on the Kzriders forum. This is pretty good info and it should be shared with everyone. Here is the link. Take a look and post your replys on what your thoughts are. http://kzrider.com/forum/3-carbureto...-carbs-to-29mm

[azr]

Interesting thread, thanks for posting. Didn't completely understand what he was milling down the slide, he calls it the "recess in the bottom". I'll have to look at a carb body to understand it I guess. This sure seems like a cheaper route. I wonder how a milled set compares to a true set of 29mms ?

[chuck hahn]

Theres a little ring area for the rims of the slides to drop into.

[tbirdhd]

questions are , Is it worth doing and where can we get it done , and the big one , COST #$$$$

[chuck hahn]

Just signed in over there and sent him a PM. Will report back if he responds.

[Agemax]

why not just buy a used set of VM28's? (as fitted to the UK spec. GS1000S and N models)they measure almost 29mm at the inlet bore anyway (28.8 IIRC)

[chuck hahn]

But what are their availability and cost? Whats the cost if this guy is doing it for extra cash on the side?? This is the question I asked him in my PM..whats the cost and is he in business to do them on the side.

[azr]

I've got a good machine shop in town that could do this. Next time I can remember I'll swing by and have a chat with them. I really can't imagine they nearly as much of a performance upgrade as a true set of VM 29mms though.

[Warren]

I have a set of spare carbs that I am going to do. I will post how it goes. I believe what he means by recess where the slides go. When you bore out the intake side ID it will push down the material you are cutting off into where the slide has to come down and seat. It actually creates a burr. You need to mill this burr off. If not the slide will not seat all the way down and your needle will not seat at the correct height. This looks to be a very simple process. I believe that this a very easy and quick performance up grade. I have a performance book on the Suzuki Gs750's and it has a small artical on this subject, that the guys racing the Super bikes did this article on this modification.

Cheers,
Hope everyone likes this. I will post how this goes!

[chuck hahn]

Any way you could post up the article???

[Warren]

Vm26mm boring out to 29mm

Here is the manual that I read this in.