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Resurrecting a 79 CB750F SS

Trying to figure out which is the main and which is the primary jet. The PO had the 98 size jet in the upper port/hole.

jets.jpg

I was able to read the numbers at work today.

The primary, upper one, had a 98 in it and the lower one had a 120. I guess that's because it had pod filters on the carbs.
 
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Thanks! I've been reading that for most of the day... I'm still a bit puzzled about the jets though. It looks like the PO moved the secondary 98 to the main and installed 120's in the secondary position. So instead of 68/98 it's 98/120. Does that sound like something a person would do when adding pods?
 
75-115 works good on a podded headered DOHC and 120 is too big for a stock muffler. The guy was flopping around like a dead fish trying to rejet for the pods. Maybe 72-102 for stock mufflers, just a guess but should be close. You may well be happy at the OEM jets and many are. When they rejet up for CVs (a no-no anyway) and they don't get a good result then they jet up more being completely lost on how the CV's work.

Carb bowl #2 just has to drop straight down to clear the pump shaft. The shaft simply goes into the guiding hole and bowl goes straight up when reinstalling it.

Yank the plugs, with the jets fallen out likely the plugs are wet fouled and you will not start like that. The plugs have to be dry. I use acetone myself, or let them sit in alcohol a minute then dry. Whirl starter over a bit with plugs out to dry the cylinders out a bit. Better result to let bike sit a day to air them out.

Helicoil is the fix for the stripped VC bolt. People just can't grasp the concept of a hit solid and stop bolt like used there, they keep thinking they have to torque it and the ones with VC gasket leak that think you overtighten the bolt to stop a leak? Well, they are forced to buy whopping numbers of broken parts over. I see people breaking that type bolt all day long on cars, they are much easier to work with but just trying telling people that. No, they only accept things being harder and not finding it so make it so.
 
Thanks for the info AMC. I checked for spark today. No spark on 1 and 4. Spark on 3. So it looks like the left coil is shot. I'm going to pursue this later. Right now I have the carb apart and they are a hot mess.

You're right about the dead fish part. The screw on the bowls were in horrible shape. I'm going to order new screws and O rings from Sean soon.
 
They don't go bad often, swap the two and see if the spark issue changes pairs. The only thing that will spit them out fast is to use less than 3 ohm resistance coils, which will kill the main ignition transistor in them really quick. Too much amperage.

If they have melted the potting compound out of the bottoms, that is no evidence of being bad, the early ones did that all day long and wrong choice of compound used there, Honda figured it out and changed them. It's a tar which pretty much still coats the crucial parts even if most of it has dripped out. I've used them for years like that.

People rave about these and far cheaper than any OEM solution...............that's a PAIR of them at that price.

http://www.procomeng.com/estore/featured-products/pe-c-mh900-a.html

Yes they fit the DOHC 750.
 
Where is a good place to get jets? I plan to go back to stock, 68 and 98. I was ready to order from jetrus but that 8 bucks for shipping pissed me off. I've tried several searches with no luck.
 
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