Pilot Jets

[MPittma100]

Just when I thought I knew all there was to know about pilot jets, I was thrown a curve today.

Working on a set of 1981H carbs. It needed new pilot jets plus the normal other pieces. I ordered Yamaha part number 4G0-14142-42-A0 from Partzilla. I assumed that the correct Yamaha part would be Mikuni brand in a Yamaha bag. Plus they were cheaper than the same Mikuni Jets from Jetsrus.

Jets taken out were the typical 6 hole 42.5 pilots.

So I receive the ones from Partzilla in their official little Yamaha bag and those pilot jets have no holes in them at all? I am thinking that these are surely incorrect. Anyone know what might be the issue here?

On another subject, the floats were set really high (in the bowl) at 20mm instead of the required 23mm. Can't imagine how this bike was performing?

[bikerphil]

They should be fine, just compare the bottom spray nozzle end, making sure they are the same. It has been proven that the no hole version works fine, maybe someone else can confirm that just to be sure.

[TopCatGr58]

Hey Mike,

See this thread, start at post #99.

http://www.xs11.com/forum/showthread.php?t=43908&page=7

Also, see this page on MikeXS....I remember seeing the phrase they have below their pilot jet comparison graphic several years ago, I didn't think much about it at the time, but NOW it makes more sense to me!

http://www.mikesxs.net/products-39.html#products

T.C.

[GLoweVA]

I'm running all 4 of those "new" pilot jets in my SG just fine.
I thought the same thing a few years ago too. I put a lengthy thread about it too.