Porting specs for the 100 cc Sachs

[Richard]

Mike,

I don't have a 26mm or 24mm bing to measure but I do have a couple of 27mm bings.  The thin area measured about 0.065 inches plus or minus about 0.003 (it was hard to get an accurate measurement and this is the range that I found).  I think I remember reading in the past that the 27mm could be bored out to 27.5mm which would make the thin area around 0.056 if cut on the center of the old hole, I think.  That still doesn't sound to thin to me.

If you have a 26mm carburetor, could you measure the thin area?

Best regards, Richard

[Dwight Rudder]

The 27mm Bing was a 27.5mm bore.
Dwight

quote:Originally posted by Richard

Mike,

I don't have a 26mm or 24mm bing to measure but I do have a couple of 27mm bings.  The thin area measured about 0.065 inches plus or minus about 0.003 (it was hard to get an accurate measurement and this is the range that I found).  I think I remember reading in the past that the 27mm could be bored out to 27.5mm which would make the thin area around 0.056 if cut on the center of the old hole, I think.  That still doesn't sound to thin to me.

If you have a 26mm carburetor, could you measure the thin area?

Best regards, Richard

[brian kirby]

'74-'79 Yamaha DT250s came with 28mm Mikuni VM28s. They are painted black from Yamaha so if you see one on eBay dont be put off because its not bare aluminum. I think I paid $15 for one a while back, granted it needed some parts to work properly, but still it was a good deal.

Brian

'72 Six Day (on loan from Ernie P.)