Pressed in #35 Jet center passage size

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Bill Kemp
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Pressed in #35 Jet center passage size

Post by Bill Kemp »

Hello all. Back to the experts for some help.

I have removed the pressed in jets and cleaned them but I am troubled by the size of the hole that runs through the center of the jet towards the 8 emulsion holes In the lower section.

The center passage hole after I cleaned it out appears to be almost the same size as one of the 8 holes in the lower section. Is this correct or do I still have a blockage of the center section of the jet.

If it is a size 35 jet what size drill bit should go through it to make sure it is properly cleaned out fully.

I had to remove them a second time as I forgot to clean the center passage. (I know how dumb). It was fully clogged in all of them. Not a little bit of light shone through.

Anyway. I appreciate your help on the matter and want to be sure they are cleaned out fully before I install them again.

Also: when I took the carbs apart there was no rubber plug covering the pressed in jet tube. (I see this rubber plug on the parts diagram but it was not on any of the 6 carbs). I am positive these have never been apart so I am thinking they might not be on a 1980 Carb set???

Looking forward to hearing from you all

Thanks again for the assistance

Bill

daves79x
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Re: Pressed in #35 Jet center passage size

Post by daves79x »

No rubber plugs in the '80-'82 carbs. The #35 jet holes are tiny. The smallest wire jet gauge I have just goes through. You can heat the jet with a propane torch to crystallize the tar plugging it.

Dave

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CBX-tras
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Re: Pressed in #35 Jet center passage size

Post by CBX-tras »

I drill them out to a .38 anyway. These where lean to begin with. Will help with starting and overall performance. (Just my professional opinion).

Even some of the smallest CC Honda's use a #35 pilot jet.

I use an extended length #79 bit and a pin vise to drill these by hand.

Bill Kemp
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Re: Pressed in #35 Jet center passage size

Post by Bill Kemp »

Thanks guys. That hole is very tiny. I have a pin vice drill bit set but did not want to use it until I heard from the experts on this forum.

I used a high e string guitar wire to clear the holes but they look very tiny



🤠🤠🤠

Bill Kemp
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Re: Pressed in #35 Jet center passage size

Post by Bill Kemp »

I know this is a silly question but is it wise to increase the size of the pressed in jet by using a #79 bit. I know we are talking minute differences but how will it effect the running of the bike.

Will it foul the plugs or cause starting issues.

I just want to be cautious so I don't make any errors.

Have many of you increased this jet size by using the drill bit

Bill

Ps. If you don't want to respond on an open forum would you send me a pm expressing your thoughts

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Re: Pressed in #35 Jet center passage size

Post by NobleHops »

We did the #38 pilots in a mostly stock CBX and it started and idled really notably easily, stunk like it was rich, and was not as crisp in throttle response. YMMV.
Nils Menten
Tucson, Arizona, USA '80 CBX, sort-of restored :-)

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Re: Pressed in #35 Jet center passage size

Post by CBX-tras »

I did one CBX that wanted #42 idle jets. And everyone knows what it takes to tilt the motor, remove the rack, extract the jets, modify them and put it all back together. Did it twice to get there, first the #38's, during a normal rebuild, then up to #40's, again to #42's.
So, I don't say this as a casual thing to do.
If you want to stay on the side of caution, use a #80 drill. Or, better still, BUY new #35's and install those. That way you won't have to worry if you used the drill properly.
Sirius is on your side of the lake, they stock them.

BTW, the typical air density % in Tuscon is over 6000 ft. on a warm day whereas Toronto can be around MINUS 100 ft. Many things affect tuning and how an internal combustion motor performs. Another reason YMMV.

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