Keihinpw20hov carb
 

I am trying to rebuild a keihin 20hov carb and have a number of questions. First the serial on the engine is ca95e-3103499 although the stamp on the carb is simply ca95. I ordered a ca95 kit but parts were different from mine. Carb has a 105 main and 35 slow jet. Would a 100 main and 40 slow work? Would it require a different needle? Does the hole in the slow jet go all the way through? If so, the jet on mine is clogged. The floats had a hole in them and although I can solder them, I'd prefer to replace them but I am having trouble finding replacements. Finially I was following the carb rebuild on the forum, but the link to part two seems to be broken. Any help here?
Thanks in advance,
Waltw

Quote:First the serial on the engine is ca95e-3103499 although the stamp on the carb is simply ca95. I ordered a ca95 kit but parts were different from mine.

Ordering wrong carb kits for these bikes is a chronic problem. I wish my shop were together so I could give you part numbers, but I'm still rebuilding it due to a move so I only give direction at this point.

Go to Hondarestoration.com and get the parts blow up for your carb.

Honda still sells the float valve, the most key part. You can call your local Honda dealer to order it. About $15.00 and a perfect fit.

You will find new floats on eBay. Search "CA95 floats" I am pretty sure you can get them from Honda as well.

Quote: Carb has a 105 main and 35 slow jet. Would a 100 main and 40 slow work? Would it require a different needle?

Jetting is a science of its own IMO. Usually jetting changes are made due to elevation of your home state. I can't say what the difference would be and if there is a difference the two air adjustments on the carb would make up the difference. If your asking about needing a different needle at the throttle slide because of the 100 main and 40 slow jet, the answer is no. Although it may need to be set higher or lower at the "c" clip

I have cleaned and reused original jets without any issues.

Quote:Does the hole in the slow jet go all the way through? If so, the jet on mine is clogged.

The best way to tell if an air jet is clogged is to use light pressure compressed air. Another great trick suggested by another member is to use scrap guitar strings to clean out jet passageways.

I cannot stress enough the value of cleaning the carb body. You (we) have two major challenges rebuilding these carbs.

1. Getting a bowl gasket. You cannot buy the proper bowl gasket although you can cut your own out of fuel resistant material. I like to broadcast the greatest gasket company on the planet. Bowling Green Rubber & Gasket in Bowling Green, KY. These guys do gaskets for everything. I know them and have had gaskets made with great success. Call them for advice.

2. Make double sure that you set the float level perfectly. Generally speaking from the many carbs I have done, adjust the level close to the max measurement but never at the high spec.

Thank you for your advice. I am aware of the gasket problem and have been looking for specs for the float setting. Can you say more about where I might find instructions for setting the float level.
Thanks,
walt

My manuals are still packed away otherwise I would scan in the page with the float adjustment specs. Somewhere in this forum are downloads of the CA95 manual. I hope some of the more knowledgeable members will chime in and provide the answer.

The manuals are in this ZIP file.

Within the file, navigate to the Service manual, then open the PDF file named "01.Engine.pdf". Pages 64-69 cover the carb, with illustrations, jetting, adjustments all covered. Cheers.

Many thanks
 

Thanks to all replies. I'll let you know how things work out.
waltw

Step 1 -it runs
 

Followed your advice, I completely cleaned the carb, got new gaskets, and adjusted the float (actually I had to solder holes in the old float).
Now it runs -maybe not well but this thing has been sitting for over 40 years, and someone left gas in the tank. Only has 400 miles on it but... I changed the oil, but suspect that there is a lot od gunk in the rings maybe. I have a video of it running if I can figure out how to post it. New problem though, the clutch is frozen in the engaged position. Any ideas of how to fix this would be appreciated.
Walt

Assuming your clutch cable is not bound,

You will notice a rather large slotted adjustment on the left side of the engine. This is your clutch adjuster. I suspect that the adjustment actuator may bound up with dirt and old grease. Remove the side cover that houses this adjuster, remove the adjuster assembly from the housing and solvent clean it.

While your in there, you will see a push rod. Pull the pushrod and clean it as well and reassemble and adjust the clutch by turning the slot until you feel pressure, tighten the 10mm bolt and further adjust the clutch at the side cover housing and handlebar to the point that the clutch does not slip and you don't grind gears.

Another avenue is your clutch plates are glued together with old burnt oil and rust. Pull the right side engine cover to expose the clutch basket. You may want to do this at the same time you clean the clutch adjuster.

Unscrew the 4 bolts on the clutch "pressure plate" and remove the plates and discs. Try to record the sequence of the clutch plates as you remove them.

Clean the clutch plates and scuff them with 150 grit w/d sand paper (wet) You might even be able to reuse the clutch plates if they look good (meaning they have some definition between the keystone pattern tabs).

Finally, use non detergent 30 wt oil. Do not use Chevron 30 wt oil. The Chevron 30wt oil glued my clutch plates tight and I had to do the above step.

You may need a gasket for the right side engine cover. If not, Permatex Ultra Black Gasket product works well.

Good Luck!

Thanks, I'll give it a try.

new problem
 

pan head screws are really stuck to the clutch housing, and I had to drill out some to get it off. Now I need new pan head screws and no one around here seems to carry them, best place to get them?

Hey Walt,
I'm in Oz, but I'd look at Westernhills Honda first, followed by cmsnl.com
Kev

Your Honda dealer will have the screws. In a pinch you can replace the bad pan head screws with hex head metric screws usually found at any good hardware store.

[ New problem though, the clutch is frozen in the engaged position. Any ideas of how to fix this would be appreciated.
Walt[/quote]

I have encountered frozen clutches before and what I try first is warming up the bike in Neutral (so it will start easy), then restarting in 2nd gear with the clutch pulled in, and needless to say, me on the bike pointed in a safe clear direction. Usually a quick blip of the throttle when I'm moving is all that's needed to free up a stuck clutch disk. This trick assumes a working clutch that has pull resistance at the lever.

Don't ca95s have voodoo screws where the thread pitch is different from modern metric screws found at the hardware store? I ordered exhaust studs for my painfully slow benly refubishing project and they are different from all the nuts filed in my coffee can of metric nuts and bolts.:confused:They didn't fit the treadserts that I was trying to use either. curses, foiled again!

The engine fasteners (screws & nuts) are mostly modern pitch metric type. There are some 1.25's "voodoo screws" like your exhaust manifold studs, handlebar control casings and tank badges. The exhaust studs I believe are 1.25 pitch in the cylinder and 1.0 pitch at the nut end....I have to check my spares....