Topic: Where can I find low speed jet's for 78 CB750?

[UPHOTO]

My mechanic is having a tough time finding these and I thought I would ask around too.

40's is what I need for the low speed's.  Everything we've found is for the earlier threaded style and not the push in's.

Anybody have a source for these?

[UPHOTO]

Another question too.....

Anybody ever heard of taking these press in style carbs and tapping the pilot's to accept the screw in types?

That's something he wants to do if we can't find the press in's.

PO mangled the low speed's big time.

[mick750F]

  AFAIK press in jets are made of unobtanium. This site has the right jets I believe but they are threaded. They suggest that they can be used as a press in using something like Loktite in the threads because the diameter is the same.

http://www.motorcyclecarbs.com/

Mike

[UPHOTO]

Thank you Mike.

Got some threaded ones right now and trying to figure out the best way to do this.

loktite idea scares me......what is you have to replace them again? 

Looking into either tapping them or creating a sleeve for them.

[brewsky]

This site lists them as available, sometimes you have to read the detailed description to see all the models they fit.
http://www.siriusconinc.com/pro-detail.php?pid=&product_id=1807

[Tintop]

Would highly recommend Sirius.  Have bought a number of carb parts for my 550 project from them.  If you order from their site using Paypal, it ships next day.

[manjisann]

If Sirius doesn't have them I've had some really good experience with jetsrus.com. I'm not sure if they have the press in's though. One thought, what about spinning the threads down and creating a groove with an oring in it. I'd be a bit hesitant to tap the carbs, mostly because I hate alterations to such things that can't be easily found.

Brandon

[eurban]

Sirius has press in pilots which is the way to go.  Why do you think you need #40's? The stock #35s are more than adequate for most (including performance oriented) applications.  Most of the time the issue is that the stock jets and associated passages aren't properly clean.

[UPHOTO]

Thank you everybody.

eurban, I think I agree with you.  My mechanic keeps saying that's the way it needs to go.

[mick750F]

   Didn't know Sirius carried them now. +1 on what eurban says.

Mike

[eurban]

Thank you everybody.

eurban, I think I agree with you.  My mechanic keeps saying that's the way it needs to go.

Seems to be an abundance of the bigger is better thinking out there.  Fact is less is often more! . . .Start with clean stock size jets and properly functioning carbs. This means that things like the accelerator pump must be working, pilot circuit most be properly clean and in general all the bikes systems up to snuff.  If you find that off idle performance continues to improve with each additional 1/4 turn out on the idle mixture screw and you have reached 3 (or so) turns out, then it would be time to up to the next size larger pilot which is probably a 38.  Throwing a #40 at it "just because" is going to be a mistake which you actually paying money for.

[TwoTired]

I agree with eurban.

Another issue with running the pilots too rich is cylinder wall washing that leads to early ring/cylinder wear.

Early carbs have no choice (without an accelerator pump).  But the PD carbs were used so that the idle could be lean, and the accel pump restored good throttle response (if it is working correctly).

Cheers,

[UPHOTO]

Awesome info everybody!

Good news is that the bike is running great without the new pilot jets so no major rush and also proof that the stock size is good (still have a turn in a half left of adjustment).

They are mangled and crooked so it will only get better with the new jet's.

Thanks again brewsky for the great find.

[brewsky]

Awesome info everybody!

Good news is that the bike is running great without the new pilot jets so no major rush and also proof that the stock size is good (still have a turn in a half left of adjustment).

They are mangled and crooked so it will only get better with the new jet's.

Thanks again brewsky for the great find.

No problem... I thought I was going to have to replace mine after they gave me a fit trying to remove, but finally got them out without major damage.
I've bought other stuff from Sirus and was pleased.