Topic: Looking for press-in pilot jets for PD Carbs: Bumping up from my 35s. WHERE?

[DoctorMuffn]

I just got back from Mexico. I spent 9 weeks down there learning farm work, construction, doing hard manual labor, and of course immersing myself in Spanish. I'm back and I'm about to go get my CB from a friend's house today. The problem of snap throttle cutout or lean hesitation (or whatever it's called) which I had before leaving roughly 2 months ago persists. And in working with some folks here I've concluded that changing out the pilot (or idle) jets was the next best thing to try to see if it remedies my problem. I'm trying to change the low speed jets from 35s to 40s or 42s; they're the jets in the middle - not the idle mixture screw and not the big jets center bowl with the needle down the middle of them.

They're press-in jets and I'm looking for press-in upgrades. Where can I get them?

Thanks

[Jiminy Indy]

Check my post from earlier this morning and the replies..

Found them at Sirius.

[Jiminy Indy]

http://www.siriusconinc.com/pro-detail.php?pid=&product_id=1107

Martin

For more parts visit: www.siriusconinc.com 
(no eBay fees means 10% lower prices and 10% lower shipping for you!)
For accessories visit: www.siriusmotosportsinc.com

Sirius Consolidated Inc.
44 Saltsman Dr, Unit 8
Cambridge Business Park
Cambridge, Ontario N3H 4R7
Canada

FAX: 888 894-2755
sci@siriusconinc.com

TUES - THURS 9-6
FRIDAY 9-1
SAT - SUN - MON ON-LINE SHOPPING

[Jiminy Indy]

BTW - this LINK I just posted is for the stock #35 jets.

[lucky]

I just got back from Mexico. I spent 9 weeks down there learning farm work, construction, doing hard manual labor, and of course immersing myself in Spanish. I'm back and I'm about to go get my CB from a friend's house today. The problem of snap throttle cutout or lean hesitation (or whatever it's called) which I had before leaving roughly 2 months ago persists. And in working with some folks here I've concluded that changing out the pilot (or idle) jets was the next best thing to try to see if it remedies my problem. I'm trying to change the low speed jets from 35s to 40s or 42s; they're the jets in the middle - not the idle mixture screw and not the big jets center bowl with the needle down the middle of them.

They're press-in jets and I'm looking for press-in upgrades. Where can I get them?

Thanks

If you give me all the info about your bike it would help me to help you with getting your motorcycle to run right.

Facts:
1977-78 CB750. (press in idle jets)
Intake type?
Exhaust type?
main jet size?
Needle position if it is a 1977.
If it is a 1978 it has a non adjustable needle on the slide.

HAs the float needle been replaced in the last two years?

[DoctorMuffn]

Yeah, Lucky, you were helping me out with it before... I checked my private messages after posting this and saw you there. Unfortunately I can't search and find my old thread where I gave you all that info, but (I think) you and I pretty much concluded that going from 35s to 40s or 42s was the way to go. I also upped the needles by placing washers under their C-clips but that didn't help much to improve the low speed throttle-on or off-idle throttle response. Then I couldn't locate the pilot jets before I had to leave so here I am now that I'm back. In the pm you sent me you were focussing on the accelerator pump restrictors which I'll take a look at next if changing the pilot jets don't help.

And thanks, Jiminy Indy, I'll check out that link right now. I'll let you guys know if I find what I'm looking for.

Thanks to all

[DoctorMuffn]

Found all sorts of the friction fit/press fit slow jets on that site. Thanks, Jiminy Indy.

[lucky]

Yeah, Lucky, you were helping me out with it before... I checked my private messages after posting this and saw you there. Unfortunately I can't search and find my old thread where I gave you all that info, but (I think) you and I pretty much concluded that going from 35s to 40s or 42s was the way to go. I also upped the needles by placing washers under their C-clips but that didn't help much to improve the low speed throttle-on or off-idle throttle response. Then I couldn't locate the pilot jets before I had to leave so here I am now that I'm back. In the pm you sent me you were focussing on the accelerator pump restrictors which I'll take a look at next if changing the pilot jets don't help.

And thanks, Jiminy Indy, I'll check out that link right now. I'll let you guys know if I find what I'm looking for.

Thanks to all

Ok...Sounds like you have a plan. The needle on the slide only controls 1/4 to full throttle. The idle jet and mixture screw is what controls throttle from 0-1/4 turn.

[DoctorMuffn]

Bumped up from the 35s to the 40s thanks to Jiminy Indy for suggesting Siriusconinc and lucky for his advice. I noticed an immediate difference in the throttle response off idle and at speed as well as a reduction of flatspots throughout the powerband. The bike is too fast for the brakes now and in 5 gear breaths and fuels so well it slips the clutch; the clutch does have 60k miles so it might be time to change it out anyway. And now I believe that bumping up to the 45s might make for perfect running conditions at all throttle positions including, and especially, off idle full-throttle goose.

Thanks for all the help! It's great addressing and fixing a problem and having some logical rational to back up why it works.

And thanks to Bob Wessner for his search function sticky. Nice to find my threads again.