Pilot jets.

[Tim L]

Hi all,
I have just removed my pilot jets to clean the carbs.
The new jets I have bought are the VM22/210 type, which are correct for a 77D.
The old ones that came out of the carb have no air bleed holes at all so they can't be BS30/96 or VM22/210.
Has anyone ever seen pilot jets with no air bleed holes?
I am a bit confused.
Tim.

 

[5twins]

Yes, the stock pilots used on the '77 and '78-'79 BS38s are a "no hole" version of the VM22/210. Yamaha used them in XS500 carbs as well. The way they mount and flow in the BS38s, side holes aren't needed. Usually that's where the air is added but on these particular carbs, the air is fed in above the jet. The jet flows just fuel. I think Yamaha contracted to have them made special. I'm thinking they may have been cheaper to produce because less work was required to make them.

There are no worries about using normal VM22/210 pilots with the holes down the sides. They'll work just fine. If you wanted "no hole" ones, you'd have to scrounge them from other carb sets. The '77 carbs had #25's, the '78-'79 carbs had #27.5's, and the XS500 carbs had #30's.