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Blood Sweat Tears and Grease => Engines => Topic started by: ryan_289 on Jul 11, 2018, 00:09:55

Title: Just picked up a cb360. Stuck engine help.
Post by: ryan_289 on Jul 11, 2018, 00:09:55
I just picked up a 76 cb360 from a guy at work. He claimed he picked it up in a package deal and the engine is stuck.  I got it home tonight and the po had filled the crank case with what smelled like transmission fluid.  I stuck my cord camera down the spark plug holes and they were dry. I filled the cylinders with corrosionx and will rock it around over the next few days. If that doesn't work are there any other suggestions to help unstick it?   Here are a few pics. Excuse the mess, I'm in the middle of a few projects.  My goal is to end up with a tracker/scrambler type bike.  This is my first motorcycle in about 20 years!(https://uploads.tapatalk-cdn.com/20180711/95bfe03889054dd73075a2dfd34b7cf6.jpg)(https://uploads.tapatalk-cdn.com/20180711/9575ee25eaa1241626f365c2181e3406.jpg)(https://uploads.tapatalk-cdn.com/20180711/799807f2d69a00a3aa092896167a8bf5.jpg)(https://uploads.tapatalk-cdn.com/20180711/a13a0e3ee3e00b82f335feeb9b5b4646.jpg)

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Title: Re: Just picked up a cb360. Stuck engine help.
Post by: Spoonz on Jul 11, 2018, 00:43:48
If itís stuck, once you get it unstuck you are probably going to need to rebuild the topend at least.
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: advCo on Jul 11, 2018, 02:25:43
ATF and acetone 50/50 in the cylinders. Fill em up. Wait a week. See if it turns over. Donít force it either way.

Like spoonz said youíll probably want to rebuild the top end, at the minimum rings and a hone on a stuck motor...so you can just pull the head off, break the jugs free with a rubber mallet or deadblow, place some blocks underneath to raise it off the crankcase and then tap the pistons down with a block of wood.


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Title: Re: Just picked up a cb360. Stuck engine help.
Post by: MiniatureNinja on Jul 11, 2018, 03:02:35
If the engine is stuck, there are bare minimum things that you will need to do... go ahead and pull the motor, take it apart. You can free pistons with a good soak of marvel mystery oil, just let them soak in there for a few days. Rock back and forth gently, motor like to spin counterclockwise but a few degrees back wont hurt it.
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: ryan_289 on Jul 11, 2018, 17:05:59
Any recommendations on rebuild threads or videos?  I've never been into a motorcycle engine.

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Title: Re: Just picked up a cb360. Stuck engine help.
Post by: MiniatureNinja on Jul 11, 2018, 17:57:20
Sderbyshire thread just below yours, pjcrazy tons of info, mine in my signature, trek, there really are a ton of them on this forum alone
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: ryan_289 on Jul 11, 2018, 22:51:31
Success!  Went out to the shop and put it in high gear and she broke loose.  Still may need a top end rebuild but now it will be easier to take apart.  I'm going to at least try and get it to fire off first though.

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Title: Re: Just picked up a cb360. Stuck engine help.
Post by: MiniatureNinja on Jul 11, 2018, 22:55:31
Success!  Went out to the shop and put it in high gear and she broke loose.  Still may need a top end rebuild but now it will be easier to take apart.  I'm going to at least try and get it to fire off first though.

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if the engine was stuck, you run a pretty serious risk of grenading it - it turns over, that's great... is firing it up worth it?
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: trek97 on Jul 11, 2018, 22:57:45
I'm going to at least try and get it to fire off first though.

I would pull the head cover and make sure everything is working smoothly, cam is turning, all valves working, tons of lube...etc.  check valve clearance.
Then fire that thing up.

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Title: Re: Just picked up a cb360. Stuck engine help.
Post by: ryan_289 on Jul 11, 2018, 23:28:08
if the engine was stuck, you run a pretty serious risk of grenading it - it turns over, that's great... is firing it up worth it?
Are motorcycle engines that delicate?  I've unstuck old flathead jeep engines before and fired them off with no issues. Serious question, I've never worked on a small engine.  I guess they are running quite a bit faster than an old jeep with smaller parts to boot!

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Title: Re: Just picked up a cb360. Stuck engine help.
Post by: irk miller on Jul 12, 2018, 00:01:39
They aren't that delicate, and they're not necessarily that precise.  I'd pull the top end off (tappet cover and head) and assess the damage.  A stuck engine is not necessarily pistons. 
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: MiniatureNinja on Jul 12, 2018, 01:42:06
No, they are not any more delicate than other over head cam engines, but take a look at some of the build threads to see what happens when they dont get proper lubrication or cam chain tensioner failure (something these engines are very prone to)

As irk said: at the very least pull the top cover off and make sure things spin correctly.
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: ryan_289 on Jul 12, 2018, 11:46:48
Yea I will for sure take a look.  Ill probably end up rebuilding anyway.
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: ryan_289 on Jul 12, 2018, 11:52:33
Are there any recommendations on engine parts and gaskets?  Honda only or will aftermarket be ok?  I want to keep costs at a minimum but I do not want to skimp when it comes to internal engine components.
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: advCo on Jul 12, 2018, 13:31:27
Honestly, I know people who have had stuck pistons, got em free and ran the motors for thousands of miles. I'm not saying its a good idea, and they've probably been lucky with just a little bit of rust on the rings, but its been done before. If it were me, I'd definitely want to check it out if you're planning to keep it.

For gaskets and stuff, I would always go with Honda OEM. You can get a complete gasket kit for the 360 for around $50.

Whatever you do, make sure the oil slinger inside the right hand cover is clean, as that is a primary cause for oil starvation to the head.

As for tensioner failure, check your engine number for a punch mark above and below the "-" in the engine number. These will indicate that factory recall work has been done including the tensioner fix.
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: ryan_289 on Jul 12, 2018, 14:59:10


For gaskets and stuff, I would always go with Honda OEM. You can get a complete gasket kit for the 360 for around $50.

Whatever you do, make sure the oil slinger inside the right hand cover is clean, as that is a primary cause for oil starvation to the head.

As for tensioner failure, check your engine number for a punch mark above and below the "-" in the engine number. These will indicate that factory recall work has been done including the tensioner fix.

My engine has no punch marks but the serial number is 2218613.  I think that is over the serial number range that was affected, its a 1976.

Where are you finding OEM gasket kits for $50?
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: advCo on Jul 12, 2018, 15:02:46
My engine has no punch marks but the serial number is 2218613.  I think that is over the serial number range that was affected, its a 1976.

Where are you finding OEM gasket kits for $50?

Woops, its not OEM but I'm pretty sure I used aftermarket. I can't remember now. $35

https://www.ebay.com/itm/Engine-Gasket-Set-Kit-Honda-CB360-CB360T-CL360-1974-1976/192035680930?hash=item2cb637f2a2:g:DP8AAOSwL9pabK1Q:sc:USPSFirstClass!79356!US!-1

Common motor has them for $50:

http://www.common-motor.com/honda-cb360-overhaul-gaskets
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: trek97 on Jul 12, 2018, 17:55:58
Yes 1976 was safe after the recall. 

I like Vesrah gasket kits.
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: irk miller on Jul 12, 2018, 19:33:02
I like Vesrah gasket kits.

+1

They're mostly what's available, they're mostly cheap, and they're probably the exact kit everyone else sells just repackaged with their name.  LOL
Title: Re: Just picked up a cb360. Stuck engine help.
Post by: trek97 on Jul 15, 2018, 08:10:37
+1

They're mostly what's available, they're mostly cheap, and they're probably the exact kit everyone else sells just repackaged with their name.  LOL

+1 +1   ;D