Stupid CB360! I've got 99 Problems and Bad Weather Ain't One

MiddleClassChops

MiddleClassChops

New Member
So my build has been basically done for a while. I put some harley take off mufflers on the bike so I have nice long exhaust now. Sent my carbs out to PJ and he did an awesome job. The bike fires on the first kick now and idles great. I still have my cheap pods on and need to replace them but I think I have a whole different issue now. Started up the bike and let it get ward. Burped the throttle and it sounds like it will surge to about 1600 RPM or so and will stay there until I either put it in gear and let out the clutch a bit or mess with the mixture screws. At the point when it surges and level off, I can rev it up and it will return to that high idle....then it seems to get pretty hot. I shut the bike off and heard a hissing noise which when I looked into it was coming from the seal at the kicker. hot oil was wanting to pump out. Also had a bit of a marble in a can sound occasionally when I took it around the block. I'm afraid it may not be getting oil in the top end. What do you guys think. Wanting to get some opinions before I pull the motor and start going through it.

BTW, I did the squirt around the intake to check for vacuum leaks and found none. Man I love fabrication but can't seem to keep a motor running to save my life!

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Sounds like the top end is starved for oil... which is a common thing for these bikes. I had a 360 do the same thing and it was oil starvation...you will have to get a new/used cam, rockers and head if its too far gone. It doesn't take much for the top end to fry. Bad engine design...I got rid of mine and will never own another again. Hope this is not the problem with your bike...good luck!
 
PJ did my camshaft and so far I havent had issues but still check to make sure a problem isnt slowly coming up.

PM him and ask about the oil channel mods he suggests, might fix the issue without too much pulling apart
 
As the owner of more grenaded 360 motors than running ones, my first worry would be that top end. Check to see if your getting oil up there and if not, you have a few options.
 
Remove a valve tappet cover while its running and see if oil is plashing around. That would be the least intrusive method.
 
Well I thought I would follow up with you guys and give you are current status. I did check that oil is getting to the top end. Oil continues to hiss out the seal at the kicker and since I'm cheap and impatient I cleaned it real good, coated it with black RTV and re installed it. Hopefully it holds up. Still confuses me why it would be hissing out with such pressure.

I ended up removing the timing advance and cleaned it real good. Replaced the springs with new XS650 springs from Mikesxs. Also put a new set of points on. It now fires up real nice. It still wants to surge a bit when it's standing still but not to the extreme that it was happening before. I gave up on the surge issue and hit the streets with it and it runs perfect on the road. I guess I can live with the weird issues at a stand still if it continues to run great on the road. Maybe I'll eventually figure it out but for now I'm just glad I can ride it.
 
Your breather tube may be blocked - is it difficult to unscrew the oil plug when the engine has been run for a bit?
 
Rich Ard said:
Your breather tube may be blocked - is it difficult to unscrew the oil plug when the engine has been run for a bit?
Click to expand...

I haven't tried unscrewing it but I thought it might be a breather issue. Is there a breather on the crankcase (cause I haven't found one) or just the one on the valve cover up top?
 
One of my biggest frustrations right now is not being able to find a vacuum leak but having the surge issue. Well I guess it's not really a surging issue, It's more about the lag in returning to idle. Stupid issue that won't go away.
 
Looked over the bike yesterday and found that my breather was blocked with something. Got that cleaned out and low and behold, no more oil leaks. Took it out for a ride and got about a half mile down the road, downshifted and the back wheel skid momentarily. That of course ended up killing the motor and I couldn't get it restarted. I did start it later that day but now it won't idle at all.

Couple thoughts. I probably need to check my jets to make sure they aren't clogged. My points screws are really stripped so there may be a chance that the points moved if they weren't tight enough. I don't really understand why the wheel locked up on me when I downshifted though. Always a mystery with this bike.
 
Well for whatever reason I decided I wanted to take a look at my top end today. I'm guess I'm glad I did. I have pulled out the cam shaft yet but I already know that I'm going to need a new head and rocker cover. Take a look at these pics.

Looks a lot like the left cylinder bath was pretty dry. The second lobe didn't have any oil on it.

I don't know. Part of me feels like the 360 motor is more trouble than it's worth. I saw a couple cool xr600 swaps done but here in idaho, finding a cheap xr500 or xr600 is near impossible.

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Thats seen some heat alright! Did you do any of PJ's oil mods? I was pretty concerned with oiling problems so I did them and so far the lobs have been wet and actually in better condition than when I installed it (go figure!). There are details of them in someone's build thread and they are pretty easy.
 
Nope. didn't do any oil mods. This is the first time I've had the top end apart. Guess I should have waited cause now I need a new one.

So I'm about to buy a new head off ebay. Does anybody have some advice as to what procedure I should go through in checking the oiling system before I install a new top end?

I know I need to find the thread with pjs oil mods too.
 
Cut the neck off, roll a CB350 into your garage, and weld the neck onto it. Boom, problem solved.
 
Like the 350 with it's tiny plunger pump didn;t have any top end oiling problems?

Hell, roll in a Virago and weld the neck to it....Viragos never break down or lose their bearings or anything.... 8)
 
Wow with friends like you guys! Thanks for the encouragement. I ended up finding a complete head with rockers and cam on ebay. The bike it came off of sat for 20 years in a barn so the outside is real dirty but the insides are awesome (like me). Anyway $55 later. Can't beat that. Guess I need to gen on buying some new gaskets and stuff. I'll go ahead and document my head rebuild here so people as dumb as me can have some pictures to follow.
 
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