TOPIC:

If you search for "passage plug" on Z1 Enterprises, they have three different ones that are completely rubber. I was going to order a package of those tonight (something like $8 I think) because I am 90% sure they will be fine. I can let everyone know how those fit, although that might not be until middle of next week.

Going back to the question about the jets - can I just swap in the jets that are better for top end, or did those bikes come from the factory with better headers and/or different air box design? I do have an N10A needle.

7-Fiddy LTD wrote: If you search for "passage plug" on Z1 Enterprises, they have three different ones that are completely rubber. I was going to order a package of those tonight (something like $8 I think) because I am 90% sure they will be fine. I can let everyone know how those fit, although that might not be until middle of next week.

Going back to the question about the jets - can I just swap in the jets that are better for top end, or did those bikes come from the factory with better headers and/or different air box design? I do have an N10A needle.

You won't gain power by just throwing in larger jets (on a stock bike). You will get worse gas mileage though.

7-Fiddy LTD wrote: If you search for "passage plug" on Z1 Enterprises, they have three different ones that are completely rubber. I was going to order a package of those tonight (something like $8 I think) because I am 90% sure they will be fine. I can let everyone know how those fit, although that might not be until middle of next week.
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Did that and they were fine for about a week and then they fell out. Bike wouldnt even start.

Nessism wrote: You won't gain power by just throwing in larger jets (on a stock bike). You will get worse gas mileage though.

The goal would not be to "gain power", more to shift the power band. The question was more a) can I swap the jets without swapping my needle, or do I need to swap the needle as well? And b) The KZ750E with the 62/125 jets - does that have a different airbox/exhaust as compared to a KZ750H LTD that would have the 65/90 jets, or were the jet differences to change the power band?

JR wrote: Did that and they were fine for about a week and then they fell out. Bike wouldnt even start.

Why did this happen? Did the rubber relax or did the rubber become stiff and brittle? Do you know if you bought the 4-5mm taper or the 5-6mm taper? A week seems like a pretty short time for rubber to relax, and I would bet the rubber compound is made to be in gas, so I can't see them becoming brittle... The plugs with the 5.5 - 6.2mm taper seem like they would have enough compression - about 6%.

I'm a little perplexed by the difference in the jetting between the E and H model bikes. The only real difference I'm aware of between these models is the exhaust system. Regardless, engine powerbands are not tuned by tweaking jetting. The air fuel mixture is adjusted to meet the demands of the engine and that's the extent of it.

Regarding those plugs again, the original plastic plugs stick up pretty high because the float bowl holds them in place. If anyone wants to use a rubber plug they need to be sure they stick up high enough to be pressed into the hole by the float bowl, otherwise it will fall out. The Z1 plugs are too short.

E1, E2 and E3 have the same jetting as H1, H2 , H3 and H4. If my memory does not fail, N1, N2 and F1 are the ones with different jetting and needles.

E1, E2, E3, H1, H2, H3 and H4 use N01A jet needle with 3 jets: #35 #62 #125
N1 and N2 use N10A (part 6009-1118) jet needle with 3 jets #35 #65 #95
F1 use N10C jet needle (part 16009-1142) and only 2 jets: #35 and #100

Nessim, here you can see the N01A vs N10A needle:

undiablo wrote: E1, E2 and E3 have the same jetting as H1, H2 and H3. If my memory does not fail, H4, N1, N2 and F1 are the ones with different jetting and needles.

Ah, okay then. I'm not going crazy after all!

I'm almost done rebuilding a set of these carbs. Waiting on some float bowl O-rings and float needles.

Other than the FB O-rings I've gathered all the various O-rings for these carbs in bulk. It might be fun to try to make a float bowl O-ring out of cord stock, gasoline isn't something to mess around with though.

New question for you guys familiar with these Keihin's...

I'm trying to remove the needle out of a slide. There appears to be a threaded plug holding the needle in place but that darn plug won't budge after turning with a screwdriver. I'd normally try some heat on the fastener but don't want to burn the diaphragm. Am I correct in assuming that plug unscrews? Any suggestions?

Wish I could help but I never figured out how to separate the needle trom the slide. I chickened out of using force.
Interested in an answer - if there is one - also.

Nessism wrote: New question for you guys familiar with these Keihin's...

I'm trying to remove the needle out of a slide. There appears to be a threaded plug holding the needle in place but that darn plug won't budge after turning with a screwdriver. I'd normally try some heat on the fastener but don't want to burn the diaphragm. Am I correct in assuming that plug unscrews? Any suggestions?

Yes it definitely unscrews. I had to replace mine because of fitting a Dynajet kit (that I bought from you Nessism, LOL) I didn't have to use too much excessive force to get mine to break loose, but I definitely would be wary of using heat on those. The diaphragm seems like it would be easy to burn. this is one of those cases where you need to make sure your screwdriver fits perfect in the slot. Don't just use any one you have laying about, find one that is nice and tight in the slot and you will have a lot less chance in stripping it.

I guess worst case if you do damage the diaphragm there is a company that makes new replacements, although pricey at $20 a pop

jbmindustries.com/Keihin_diaphragm.html

Yes, that bronze plug is threaded. I know it because I took them out to install de Dynojet needles.
Big plain screw driver that fits really tight is all you need. You can use some penetrant oil also. We have nothing else than WD40 here in Argentina, but I keep reading great reviews about Kano Kroil oil in the USA.