pilot jet question?

[Buck Naked]

I see in the how to section that he uses a series 21 pilot jet, would that be better than say a oe pilot jet from the dealer? I assume that there is no difference but....


Thanks,
Keith

[2004exrider]

I think the series 21 pilot is the Keihin #42 pilot jet (stock is #38), so ya it makes a difference because it starts up a lot easier.

Jimmy

[RangerRick]

When I ordered my pilot jet from Dennis Kirk awhile back it was 21 series or 22 series.The difference is they fit different types and sizes of carbs I believe since I ordered a 22 and it didnt fit so I ordered a 21 and it did.You can get any size from like a 30 to a 50 or something in either seris from them.Hope this helped some.

[Buck Naked]

I got my 42 from the dealer and installed it yesterday but have no idea if it was a series 21 or not and I was wondering if there was a difference between a series 21 and an OE Honda jet.

[RangerRick]

Oh sorry about that.No there is no difference since Keihin makes the 21 series as far as I know and that is the brand of the carb.

[GPracer2500]

Among Keihin pilot jets there are several (8) different "series". The difference between them is the shape of the jet and the location and size of the threads on the jet. Different styles of Keihin carbs require these different series. All of that is different from the "size" of the jet (e.g. 38, 40, 42, 45, etc.) which is the size of the hole in the jet which meters fuel.

The 400EX carb uses a series 26 pilot jet (the OE jet is a series 26, #38). However, a series 21 pilot jet is also compatable with the 400EX carb--meaning either series will fit the carb without issue. The only difference between a series 21 and 26 is the length of the jet from the threads to the end that has the screwdriver slot on it. A series 26 is a little shorter that a series 21. AFAIK, both series perform identically in a 400EX carb. The only thing you'll notice is that an installed series 21 will stick out a little farther.

In my experience, series 21 pilots seem more common than series 26 when you go to buy them.

[Buck Naked]

Originally posted by GPracer2500
Among Keihin pilot jets there are several (8) different "series". The difference between them is the shape of the jet and the location and size of the threads on the jet. Different styles of Keihin carbs require these different series. All of that is different from the "size" of the jet (e.g. 38, 40, 42, 45, etc.) which is the size of the hole in the jet which meters fuel.

The 400EX carb uses a series 26 pilot jet (the OE jet is a series 26, #38). However, a series 21 pilot jet is also compatable with the 400EX carb--meaning either series will fit the carb without issue. The only difference between a series 21 and 26 is the length of the jet from the threads to the end that has the screwdriver slot on it. A series 26 is a little shorter that a series 21. AFAIK, both series perform identically in a 400EX carb. The only thing you'll notice is that an installed series 21 will stick out a little farther.

In my experience, series 21 pilots seem more common than series 26 when you go to buy them.

Awesome. Thanks. I noticed in the How To section about it, that the new series 21 jet was longer than the stock 38 and when I installed my 42 it was the same length as the 38. I thought I bought the wrong jet. Once again thanks for the info.