CB360 overheating and locking up temporarily

G

Gimpy Joe

New Member
I have a '76 CB360 that starts out running great. However, after about 20 minutes the motor starts to bog down and a few minutes after that I end up on the side of the road. When this happens, the motor completely locks up (yes, it's in neutral for sure). I can't even get it to turn over. After cooling for about five minutes, I can kick it over, but there's still tons of resistance. To get running again, I have to sit there for 20 minutes letting the damn thing cool down, and then it starts right up and I can ride home. I've never even heard of this happening, and I have no idea why the bike does this.
Any feedback or advice would be welcomed.
 
You need to pull clutch cover and check pump pick up plus spring loaded oil feed in clutch cover.
It shouldn't happen, the cam normally seizes before pistons, chrck in points cover, it's probably full of oil,(sure sign cam has seized and trashed head)
You may need new motor
 
There's no oil in the points cover at all. I don't know what's going on with this. When it's running it doesn't smoke or anything, so the rings are still good, too.
 
Oil level is OK?
Your not screwing dipstick in when checking?
It should rest in position but not be screwed in.
Still need to pull clutch cover and check pick-up.
You can't see any silicon around any covers? (base/head/cam cover)
 
Sorry to hear about your problem. I'll assume you have oil in the engine, and that the oil pump is working. Could be a dirty oil filter. Have you checked your air cleaner? Dirty, clean? Have you made any modifications to bike (cam, exhaust, K & N air cleaners?) I ask, because jetting may be wrong. Check spark plugs, if they are white that indicates a lean mixture. Carb manifolds might be cracked, or loose. Check slide needle in carbs to make sure it's not loose, or ignition timing is off.
Wow, thats alot isn't it :eek: Better get to work, Saturday is only 2 days away.
 
Thanks interceptor.
I think you're right about the bike running lean. I'm going to try some new air manifolds and switch from velocity stacks to filter pods. I'm suspecting the manifolds, because before I bought the bike from a friend, he ran the bike as it is now and didn't have any problems.
 
Gimpy Joe said:
Thanks interceptor.
I think you're right about the bike running lean. I'm going to try some new air manifolds and switch from velocity stacks to filter pods. I'm suspecting the manifolds, because before I bought the bike from a friend, he ran the bike as it is now and didn't have any problems.
Click to expand...

Sounds like it is a lean issue to me. What plugs are you running? You may want to use a colder plug to deal with the issue. The stock plugs on a cb360 are NGK B8ES. You may want to get NGK B9ES or even B10ES depending on how lean you are running. They are $2.00 a peace. Could be a cheap solution to your problem.

I would also give her an oil change, clean out the cintrificult filter and the oil pump screen at the bottom of the crank case.

Keep us posted.
 
your running stacks without re-jetting ::)
no wonder it stops
it will do same with pods.
It will never run completely right without stock airbox as the parts you need don't exist.

PJ
 
My buddy had a very similar problem on his harley. Different bike but the principles are the same. It turned out there was too little tolerance between the jugs/rings.
 
Any progress? I also thought of a couple other things. Have you checked your brakes to make sure they are not grabbing while riding. (Would put a heavy load on engine) Have you looked to see if fins on jugs aren't clogged with shit, wouldn't be 'cool ' if they are. ;) Maybe a locked up or bad wheel bearing. Lastly, I don't know if this would cause any overheating problems, but maybe chain is not lined up properly or may be too tight. Good luck man, keep us posted. Well, even if it isn't any of these, at least you get to make sure everything on your bike is working properly. ::)
 
Sounds like a hot seize to me. Running too lean, pistons expand due to high temps and they seize. Rings may or may not seize too. Engine cools and you can fire it up again. You might be lucky and your rings might not be frozen. Check your compression and rejet. If youre compression is below min. then you'll need to rebuild the top end. Same thing happened on my 450.
 
sounds like your oil pump is fried and the pickup screen is probably clogged with shit, there might not be oil in the points housing because there's no oil in the head
 
interceptor said:
Sorry to hear about your problem. I'll assume you have oil in the engine, and that the oil pump is working. Could be a dirty oil filter. Have you checked your air cleaner? Dirty, clean? Have you made any modifications to bike (cam, exhaust, K & N air cleaners?) I ask, because jetting may be wrong. Check spark plugs, if they are white that indicates a lean mixture. Carb manifolds might be cracked, or loose. Check slide needle in carbs to make sure it's not loose, or ignition timing is off.
Wow, thats alot isn't it :eek: Better get to work, Saturday is only 2 days away.
Click to expand...


Check you oil filter. See if you have oil in the filter when this locking up happens. Sounds like your oil pump is shot or clogged. You might try flushing the motor with tranny fluid or something real thin. Do you have the correct oil filter? Is there even an oil filter in place?
If you try the tranny fluid run the engine for a little bit. Dont rev it up because the tranny fluid is cleanning everything out. Its not the best lubricant. Change the fluid and fill with the correct oil. CHECK THE OIL FILTER FIRST. It sounds like the oil isnt getting back down to the sump. Just like in a car. You have a pick up. If yours is like my 400 the oil comes in through the filter and up into the motor. It its not getting back down then you are slugged up or your returns are blocked. I'm not familiar with your motor but the principal is the same.
 
Mustang, it isn't what your used to.
The oil filter is centrifugal sitting on end of crankshaft.
It's just a 'cup' and almost impossible to block.
The oil pump pick up does get clogged pretty easy, particularly when people cheap out and use silicon sealer on gaskets.
It's more than likely a combination of things and needs a good going through.
The trochoids in pump can crack but most common problem with 360 is cam bearings seize up if oil pressure gets restricted or if they are operated at high rpm for extended periods.
Running modified exhaust and pods is going to be lean and cause extra heat which makes partial seizure more than possible
 
Crazypj,

What jetting would you do if you go to straight pipes and pod filters?

I have the same setup and am trying to get my 360 running right now.
 
83scrambler said:
Crazypj,

What jetting would you do if you go to straight pipes and pod filters?

I have the same setup and am trying to get my 360 running right now.
Click to expand...

You'll need a minimum of 112 secondary main, 115 or larger may be better.
It will run like shit mid range when top end is right.
I make air correctors for screw in type carbs but haven't found a simple solution for the pressed in type air jets
You can re-set float level to 20mm which helps slightly.
DO NOT SHIM NEEDLES
It would also be a good idea to extend head pipes at least 6" ~ 8" as they will be too short to work effectively
 
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