Z1OwnersClub GB

How far can you safely throat bore vm 26's and what is best to do about needle valve seats?

warren3200gt wrote:How far can you safely throat bore vm 26's and what is best to do about needle valve seats?

I've seen quite a few sets of bored out carbs. On some the needle valve was trimmed (lowered) and on others it wasn't...

Do you know what dia they were bored to ?

warren3200gt wrote:How far can you safely throat bore vm 26's and what is best to do about needle valve seats?

I've done this a few times.
You can safely go to 29.5mm and depending on the thickness of the casting in the boot groove area up to 30mm.
All the details start at the bottom of page 15 through to 19 in my cafe racer project thread.

viewtopic.php?f=7&t=14312&start=210

Perfect ta Rob. Safe upto 29mm then.

zed1015 wrote:

warren3200gt wrote:How far can you safely throat bore vm 26's and what is best to do about needle valve seats?

I've done this a few times.
You can safely go to 29.5mm and depending on the thickness of the casting in the boot groove area up to 30mm.
All the details start at the bottom of page 15 through to 19 in my cafe racer project thread.

viewtopic.php?f=7&t=14312&start=210

Have you ever considered taking on a set for some one else.. 2 sets even... hint hint wink wink

For your sake, I hope your asking Rob and not me!

Rob, have you done a set that had both fuel and air screws? Just wondering how much taper there is on the fuel screw carb body? Bit worried about boring it which might increase the hole diameter.

warren3200gt wrote:Rob, have you done a set that had both fuel and air screws? Just wondering how much taper there is on the fuel screw carb body? Bit worried about boring it which might increase the hole diameter.

Yes! The ones i did for the alloy cafe were Suzuki GS750 VM26MM carbs which have both.
No problems.

Top man.

warren3200gt wrote:For your sake, I hope your asking Rob and not me!

Ha yes was asking Rob but im sure you do good work too...

If you have a lathe it should be easy enough.

I'm not convinced that I have enough chuck center line to bed clearance to accommodate the slide body Kev. Need to have a measure up before stripping them down.

Sorry for resurrecting this thread but the question of the needle valve seats, Rob- did you remove them or bore them out?

Z1streetfighter71 wrote:Sorry for resurrecting this thread but the question of the needle valve seats, Rob- did you remove them or bore them out?

What do you mean by needle valve seats ?