Topic: New Guy Here

[summitwrx]

I thought the same thing when I opened it up. He must have had it apart and didn't want to sell it in parts so he just threw everything in as quick as he could; some bolts were loose including a head bolt, he put the longer head bolt in the front in one section. Cant believe I paid this guy 600$!!

I have a couple of dumb questions (don't flame me):

1.I never would have thought the cam was in backwards buying it from someone who told me it runs, what could have been damaged by turning it over with the cam in backwards?

2. Are there supposed to be bearings for the cam, it can't possibly just sit in the head journals can it?(there were no bearings)

Heres what I got done today. Do i need to tear it apart further or should the bottom end be okay?







Dumb question but how do I get this chain guide/protector out of the jugs?


If anyone can recommend a good shop in Denver/Metro area that will clean/deck/valve seat the heads I would really appreciate it!

[calj737]

To remove the cam chain tensioner, there's a 10mm nut in a stud on the backside (carb side) of the jugs. Remove that nut, push the stud inward, and withdraw the tensioner up and out thru the slot in the jugs.

The cam bearings should be installed on the lowers of the journals in the head. Can't tell from your pictures, but if there wasn't a bearing, then the journal would be badly toasted as would be the cam.

Getting it to run installed backwards? Can't imagine. The intake and exhaust lobes have different profiles. Maybe it might start, but can't believe it would actually "run". Possible damage? Exhaust valves smashing into pistons sounds quite possible.

Send a PM to Hondaman or place a Services Needed ad looking for advice and recommendations on a machine shop in Denver.

You may not want to hear this, but if it were me, given what you've found already, I'd tear that motor all the way down! The potential for gasket goo to have gotten into the oil passages is too great, even if the PO never touched the lower end. His reach may easily have exceeded his touch.

$600 isn't too bad if the bike is otherwise solid. Besides, you're getting all this experience for free now rebuilding your bike!  and that's priceless!

[summitwrx]

I got the tensioner out already. what I am talking about is a plastic piece in the jugs, no bolts, its loose, but I can't seem to twist it sideways enough to get it out.

Im going to go ahead and say the valves definitely hit the pistons:







Sad day. Would it be cheaper to source a known good used engine? My wallet hasn't dared let me walk into Honda to price out oem stuff; if they even carry anything for it anymore.

I do enjoy turning wrenches and learning the bike but Im thinking I might enjoy a nice motorcycle ride in the mountains to see the fall colors a bit more 

[calj737]

The cam guide will wiggle out, just takes some fiddling.

You can't buy a new/rebuilt engine form Honda. You can find them around sometimes, but mostly, they are all going to need some rebuilding. It shouldn't cost too much if you do a clean rebuild of the jugs and head. A machine shop local to me charges me $400 to tear down, and reassemble, fully torqued and guaranteed. Boring costs extra, and any milling, but it's reliable, guaranteed, and right. Parts cost extra which I source and provide to them.

Certainly there's a decent ship within an hours drive of you that can be trusted to help you do this quickly and within a reasonable budget.

[summitwrx]

I appreciate all of your input!

[754]

Plus one on tearing it down due to he is excessive. Sealant..  If he did not split cases,  you may he able to leave lower end intact..

[summitwrx]

Can't be certain if the PO did this or the one before him... Either way, one of the more serious hack jobs I've ever seen. Is there any method to flushing the case out while I have the top end off? Probably best to just pull it apart and clean it. Trying to build it on a budget... Budget and build never seem to like each other.

[spdygnzlz]

Hey Summit, I have some 650 engine parts in a bin if you need anything. I have most of the bottom case and internals minus the crank still in a bin.  I took the top end off for my 550/650 motor hybrid which involved the crank, rods, cylinders and head.  Also have some extra rockers and covers though.  Good luck on your build!

[calj737]

If you do need to avoid splitting the cases and completing a full tear down, then do the following:

Pull the oil pan off the bike.
Inspect the oil filter and pick up for sealant goo.
Pull the oil pump out and inspect it.

If no sealant present, you are probably good to put the pan on, pump in, and rebuild the top end. But if you find and red bits in the oil pan or pump, break her all the way down.

Good luck! Maybe there's some small amount of hope.

[summitwrx]

Thanks calj737. Im in the process of sourcing a full used motor to rebuild. The more I look into things the more I am sorely disappointed. A lot of the valve cover bolts were wrong, and he wedged spring like metal material into the holes for the bolts to thread up on. Probably best to just start over.

[calj737]

Yeah, sounds sketchy. Most of the holes in the head are 6mm 1.0 pitch. Sounds as though they all need to be tapped and cleaned up.

Stainless steel bolt kits with Allen heads are available to replace the stock bolts and screws. A complete kit is about $30 should you need to go that route.

[summitwrx]

Any websites that sell those kits? Also looking for a website to purchase new valves from.

[calj737]

http://alloyboltz.com/catalog/index.php?cPath=316_358_377&osCsid=a9fj9nrag7hqclh1poifvvu5o2


http://stores.ebay.com/cruzinimage-co1484/Pistons-/_i.html?_fsub=1783269011&_sid=526414511&_trksid=p4634.c0.m322

http://dynoman.net/engine/pistons/dp-CB550.html

[754]

I have a brand new head,but there are two types.

[summitwrx]

The only marking on my head says "on14".
Having a heck of a time finding anyone that carries pistons, valves, and cam bearings. Maybe I should just buy a 750 and swap it in if there are no fitment issues.

[calj737]

A 650 frame won't hold a 750 motor. It will hold a 550 motor though. It won't be a problem to ship oyur head out to a competent machine shop and get them to service it. Mile Rieck is excellent, and there are others.

Pistons and rings are best replaced with oversized kits- cost is the same.

[seanbarney41]

I would not spend another dime on that motor.

[summitwrx]

seanbarney41 Sarcasm?

[seanbarney41]

absolutely not...that motor is ruined.  Find another one...one of the worst bases for a project I have ever seen on the interwebs or the real world...just my opinion and my advice to you

[summitwrx]

So far the bottom end looks clean. Im hoping to find a good price on a big bore kit, machining the jugs it has now, and replacing the head with a used and then re-seated head. Though it would be nice to find a full motor for the right price...

[summitwrx]

http://www.ebay.com/itm/HONDA-CB650-CBX650E-CBX650-POLICE-RC13-PISTON-ASSY-O-S-0-25-13102-ME5-000-/271402381396?pt=Motorcycles_Parts_Accessories&hash=item3f30d7b054&vxp=mtr

These would be awesome if they weren't 40$ in shipping from Malaysia.

[summitwrx]

I found a very clean top end from a 1980 cb650c,(my bike is 1981, made in 79, cb650c) where intake runners different dimensions, should my cv carbs fit the head?
Ive read there are 2 different heads in the same era for the different carbs...

[summitwrx]

Got a new head, unfortunately it won't line up with the carbs. Can I use sightly longer rubber boots to make them fit?


The head that came on the bike has this in nearly every hole, they drilled them out and put a spring like material. More than half of them are toast and won't work.

[Jerry Rxman Griffin aka MuthaF'er]

Don't take this personal but you need some help. Have you tried to get in touch with CB650? aka Terry, he lives in Hudson, just up I-76. He knows 650's inside and out and probably has some needed parts. Good guy too 

[summitwrx]

Not taken personally at all...I'm on this forum for that reason; help. I do appreciate all the help I've received from the members on here!

Figured out these are heli coils, I bought a heli coil kit and am going to re-heli coil the bad threaded holes.

I don't think the 650s had actually journal bearings as the three bikes I tore into at the salvage yard didn't have bearings, the journals on the head are just machined smooth for the camshaft.