long main jet

I just started to do the dave's mods and when it came to change the main jet I noticed that it is a lot longer than the stock one,It screws right in but reaches down almost to the bottom of the float bowl(the float bowl still closes tough)can i use it?the part # from keihin is 17-1460-158 and I got it from dennis kirk,if not wich would be the corect part #?

The main is 99101-393-___

I did dave's Mods too, and ended up with a long jet. It blew me away just how few shops actually stock jets. Calling/asking around town fro them, you'd think I was asking for some type of 'unobtanium'.

So, I ended up with the long one (was jonesing to get it started to test the mods) and figured I'd get the 'S' one when the opportunity permitted.

As far as I can tell, yes, it does obviously extend deeper into the carb bowl. But since you never want a jet to suck air, this made little consequence to me.

Who knows...longer wheelies? :thumbsup:

Monte,

If you want to go with the Honda jet, it is part #99101-357-1750 (for the 175 size. The 172 has 1720 for the last 4 numbers) from Service Honda. It is shorter and may work better with the little bowl (Jet Holder) that goes around the main jet.

I found the jet (i bought an 155 and an 160 wich is the one I finally used)in a scooter retail store,go figure.Went to the Honda shop and they only carried stock sizes.I did'nt went with the long main jet because since it extends almost to the bottom of the bowl it might suck any dirt that may find it's way down there.Upon dissasembling the carb I found some black silt in the bottom tough not that much to worry,I just put an inline filter to cure that.The mods really gave life to the bike.That,the desnorkeling and an aftermarket filter makes a BIG improvement.3rd gear wheelies :ride: and a throaty sound from the intake.That's just from a little trip round the block.Tomorrow I'll try the top end.Also i did the de-smoggin wich is pretty easy even without the kit,in fact it can be done with only 10 cents :thumbsup: just get two nickels file a little on both sides until it fits between both bolts and tighten it up.Put a little dab af silicone or epoxy if you're worried about leaks tough mine did'nt leak.I removed it latter because I was able to fabricate the plates.LOOKS like an engine now,HEY!there's an engine in there. :applause: .Some other mods includes a new chain(7 1/2 K miles on the stock one)new bars(Moose aluminum atv bend) Acerbis brush guards and universal mirrors from engo (6$ each). :applause:

It blew me away just how few shops actually stock jets. Calling/asking around town fro them, you'd think I was asking for some type of 'unobtanium'.

I'm probably one of the few people around anywhere that has Keihin main jets not only in half sizes, but also with a .250" hex (non-metric). :thumbsup:

I'd just trim a jet that was too long if the metering orifice was high enough to allow it.

What's an example of a "half-size" jet?

A jet with an orifice size between, say, a 165 and 166.

A jet with an orifice size between, say, a 165 and 166.

Interesting. Who manufactures those? Are these Keihin series 357 (i.e. "hex head") style mains your talking about?

Do you know how Keihin's main jet sizing scale correlates to actual oriface dimension? For example, I know Dynojet mains are sized by the diameter of the metering orifice in mm (e.g. DJ150 = 1.5mm diameter on the threaded end of the orifice), and Mikuni mains are sized based on flow per minute (e.g. M150 = 150cc of flow per minute), but I've never gotten clear answers on what Keihin's sizes correlate to.

thanks

I'm probably one of the few people around anywhere that has Keihin main jets not only in half sizes, but also with a .250" hex (non-metric). :thumbsup:

I'd just trim a jet that was too long if the metering orifice was high enough to allow it.

I checked the jet and the trimming could not be done because of what you said,the bottom part of the jet has a bigger hole in it and goes all the way up,maybe 3/16'" from the top also theres a countersunk hole on top wich leaves you with only 1/8" of true jet size.Maybe is the same you have since it also haves an hex head (p#17-1460-158)anyways I heard that it can be used regardless off it almost reaching the bottom of the bowl.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now