Cb360 Reassembly Help

Leave the valve stem nut off if your going to off road it. It allows stem to creep into tyre instead of tearing out of tub plus you can see it tilt if tyre creeps on rim.. Your property looks fun to ride on .Glad you got stopped OK, could have been real serious if you had been in a corner at the time. I've only ever had one tube blow without warning, luckily I was only doing about 20mph at the time. Still damn scary in traffic though
 
Not really, It's something I learned when doing Enduro's back in the 80's. Even with double rim locks the 490 Maico would spin tyre on rim. . The valve stem isn;t designed to stop tyre moving, in fact, I never could get a straight answer from Dunlop or Avon. Seems it's just there for assembly and to prevent valve stem centrifuging into tyre at high speed? I didn't use them on off road or MX bikes and never went more than finger tight on street bikes. You can see some wear on tube after a couple of thousand miles, but,I usually fitted new tubes every month (or more often) when racing., punctures were kinda common when going gets real rocky ;) I always had to find out WHY something failed then find a cure.
 
Just to be different, I put the nut on loosely and then tighten the valve cap and run the nut back up to act as a locknut against the cap.

It's not strictly necessary but on a race bike I like the extra security and I also like to see if the tire has crept around the rim.

So, what is it good for? To stop the valve stem from disappearing inside the tire when the tire is being fitted.
 
At one time I did the same for the same reason (run nut up to valve cap) I stopped doing it as it is extra weight to centrifuge inwards. (the brass nuts are relatively heavy for their size) Switched to all metal valve caps with o-ring. Looked into making some extra thin 6061 nuts but special Schrader tap was £112.20 at the time (1980's) I found some online recently for cheap, around $20.00 from China so got a couple. I'm going to make some new fittings for the Chinese gas shocks I bought few years ago Shrader uses a special thread diameter and pitch, it's close to 5/16x32 TPI but not close enough
 
You can get cheap Chinese anodized alloy valve caps at your local auto supply store.
 
Some of them are real crap, plastic valve cap with an anodised ring pushed on. Need to check them out before buying. Stuff like that wasn't anything like as available ~40 yrs ago and quite expensive for what it was (anything 'racing' extra 100% ;D )
 
I'm lucky enough to have a friend who's an aviation mechanic, so he loads his buddies up with these. They change them like every maintenance cycle or something, so they get changed a lot and they're plentiful. The metal is brass, so you can remove the powder coat and polish them up nice. They're awesome.

s-l500.jpg


https://www.ebay.com/itm/AIRCRAFT-HELICOPTER-PLANE-VALVE-STEM-TIRE-WHEEL-COVER-CAP/302984084292?hash=item468b423b44:g:tn0AAOxyJs5RaiC4
 
Having what I believe to be some carb problems. At idle the bike pops out of the right side exhaust pipe. All goes away under throttle, when riding the bike runs perfect. Revs fast and goes as fast as I want it to. Timing is spot on.

Something else weird is the idle adjustment screw isn't working. Idle doesn't change no matter what I do. I can take it for a ride and ride around about an hour and it still runs wonderful, but when it gets warm after a while it doesn't like to stay running during idle.

Any thoughts?
 
Non-functioning idle screw is often a symptom of incorrect ignition timing. That said, I know you've checked it, so maybe an air leak somewhere?
 
I sprayed with carb cleaner to see if anything would idle up, nothing happened. Are there any other ways to check air leaks?
 
Make sure you check around the rubber intake manifolds as well as the throttle shafts (the seals can sometimes leak there, too).
 
Could be sync as well. Since the butterflies are just barely open at idle, the symptoms are more evident then.
 
cb360j said:
Having what I believe to be some carb problems. At idle the bike pops out of the right side exhaust pipe. All goes away under throttle, when riding the bike runs perfect. Revs fast and goes as fast as I want it to. Timing is spot on.

Something else weird is the idle adjustment screw isn't working. Idle doesn't change no matter what I do. I can take it for a ride and ride around about an hour and it still runs wonderful, but when it gets warm after a while it doesn't like to stay running during idle.

Any thoughts?
Click to expand...
Throttle cable too tight and holding butterfly open? Have you checked carb sync? You are turning throttle adjuster and not fuel screws?
 
So I am finally going to make my own exhaust and wanted to ask a question or two before I ordered materials. I have everything sorted I think except how it will mount to the head.

Will I need to make something like what is stock? Basically a shoulder that uses those exhaust collars? Is there any easy way to make those shoulder pieces?

The idea I had was to weld a tab at the same distance as what the collar is, just high enough where those collars can be used in the same manner, would this work?
 
Nevermind, I am dumb. Just going to use a flange and weld it to the exhaust.

A better question now, will I need to sort of flare the header opening so it mashes against the gasket? Or just go with the straight normal tubing to the head
 
I use a thick washer and weld it to pipe for the flange. Fender washers may work but I wanted extra thickness in case of distoryion. Never found flaring to work too well. Last 360 system I made, I used some alloy tube slid onto pipe before welding on flange instead of the split collets and original heavy duty tube. I cut some 1/2"6061 plate to bolt to head, just used an original collar and drilled mounting holes then a hole saw for the middle.. Not as pretty as it should have been but it works and doesn't leak
 
Haven't been doing much in the way of motorcycles other than riding since PRS matches picked up.
One problem I have been having with the cb360 is the battery will lose charge in less than 24 hours, just sitting with everything turned off. One time I even rode it somewhere, parked for maybe an hour and came back to a dead battery which was really irritating because of course my seat is bolted down and I didn't have a tool to take it off with in order to ask someone for a jump start.

Any particular place I should start looking to find the problem?

Thank you
 
Parasitic loss is not a terribly common problem and can be difficult to track down, but luckily the troubleshooting is usually straight forward.

1.) Grab your multimeter and set it to read DC voltage. Then disconnect the negative terminal of the battery from the ground strap (or equivalent).
2.) The everything switched off, read voltage between the negative terminal of the battery and the cable you just disconnected from it. If you get around 12V, you have a parasitic loss. If your reading is only very small fractions of a volt or you have no reading at all, then the problem is the battery.
3.) We're going to assume you have a parasitic loss and continue the troubleshooting. Nine times out of 10, the issue is with the regulator/rectifier. As a quick test, disconnect it from the harness and repeat your measurement from step two. If the voltage loss has gone away, it's time for a new R/R (assuming it's wired correctly, that is).
4.) If the R/R wasn't the problem, it's time to start following all of the wires and cables you may have connected to the positive battery terminal. Start disconnecting things one at a time (followed be repeated measurements) until you find the culprit. The underlying issue might be something hooked up to power from the battery when it needs to be hooked up to power after the main switch.
 
When measuring dc in your step 2, what happens if I read higher than 12 volts? (This hasn't happened, I havent gotten to check things yet, but just wondering).
 
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