Honda-SOHC
SOHC.co.uk Forums => CB500/550 => Topic started by: masonmart on July 28, 2016, 05:01:12 PM
-
Just finished assembling a CB500 engine. I'd had to change the crankcases because they were cracked and I couldn't get the right main bearing shells for the replacement case/crank match. Anyway, what I've found is that even with no plugs in it's difficult to turn it over on the kick start. I can turn it over by hand using the generator. I had the casings all Cerakote coated and I have a horrible feeling he may have done the insides and the mains and camshaft bearings are gripping but maybe not. It has a 605cc kit fitted but it was never run.
This is my first build and I'm sure that the gearbox is fine and the valves and everything else does what they're supposed to do but is this something that can be seen on rebuilds and are there any fixes
-
did the crank turn easily before you fitted the pistons and barrels?
-
Did you plastigauge the shells and make sure all clearances were correct ?
How did you get it clean to Cerakote coat the engine ?
-
I once made the mistake of using Loctite bearing fit to the shells and that made the crank very stiff to turn. After scraping the stuff off, it was OK.
-
did the crank turn easily before you fitted the pistons and barrels?
John, it seemed to turn nicely before I put the top end on but I didn't check it again until I'd finished installing the top end. I improved it a bit by taking the head cover off and rubbing down the camshaft bearing surface a bit but still not enough improvement.
-
Did you plastigauge the shells and make sure all clearances were correct ?
How did you get it clean to Cerakote coat the engine ?
No I didn't measure the clearance, I measured the crank dia. and case dia. and they were the same for the ones I couldn't get the correct shells for as the ones I could so I assumed it was OK.
The exterior was shot blasted to clean the alloy for coating but I asked him to mask off the inside which I believe he did. Looks great but I was a bit careless in how I got it done.
I believe that I need to take the engine out again and rectify the problem properly. Shame because on the bike it's in I have to put the bike on it's side and take the frame off the engine.
-
Sounds a bit weird that it will turn by hand but, not on the kick, when your body weight is a lot more force. Are you sure that the kick start is not jammed ?
-
Sounds a bit weird that it will turn by hand but, not on the kick, when your body weight is a lot more force. Are you sure that the kick start is not jammed ?
Sorry trigger, I'm turning the kick start by hand not foot as the bike is up on the ramp. Normally with the plugs out it is still easy on most bikes.
-
I find it is stiff by hand .!!!
did I really say that ?????
let me rephrase it,
the kickstarter is for feet !!
see what it feels like with the plugs out ??
-
;D ;D ;D ;D Naughty boy John.
Trig says he wouldn't be able to turn the engine over by hand with no plugs in if the engine is good and tight. He says it's not a cranking handle, it's a kick start, the clue is in the name ;) ;). Unlike my 400/4 which he fires up using the kick start by hand ::) ::)
-
Ah but does he manage to start you by hand as well as the bike (Sorry couldn't resit that one Julie!)
-
Ah but does he manage to start you by hand as well as the bike (Sorry couldn't resit that one Julie!)
:o :o :o :o :o
Back to original thread me thinks ;D ;D ;D ;D
-
Ah but does he manage to start you by hand as well as the bike (Sorry couldn't resit that one Julie!)
:o :o :o :o :o
Back to original thread me thinks ;D ;D ;D ;D
good idea !! how about you leave the plugs out,squirt some light oil onto the piston ,then kick it over a few times,and if that
feels a bit better,spin it on the starter ,also check you have oil pressure,maybe remove a couple of tappet covers to see the oil
in the top .
wen you use the starter,do it for arround 5 seconds at a time,so you don't overheat it
-
The bike is on the ramp and not wired up yet so I can't try the starter. All of the rotating bits were oiled as assembled. I've tried taking off the head cover to unclamp the camshaft and that eased it off a good bit.
-
Are all the tappetts set right? Or might it just be the effort to turn over and compress valves. It is easy to catch the rockers against the valve stems when putting the cover on. It does seem the problem is top end related. I'm a bit dubious that the rockers would make it that hard to turn over if everything was right, pretty sure mine turn over ok on the kickstart even only turned over by hand, though a good kick has always been the requirement for starting it. Turning it over on the electric start does not require any more wiring than a jump lead to earth and another to the starters lead or just wap it onto the battery positive terminal as long as you are prepared for the sparks, it works fine.
-
I think you may be worrying too soon. If you can turn the full engine by hand on the crank your probably good to go. The kickstarter is quite high geared to spin the engine fast enough to start it. The starter shaft only turns half a revolution with a kick but spins the crank enough to fire. Most newly built four's won't turn by hand with the kicker unless your a Russian shot putter.
Sent from my Nexus 7 using Tapatalk
-
ive just rebuilt my cb500 with rebored barrels and new piston&rings, i struggled to turn engine over to start with and its still hard after 600 miles btw i'm 101/2 stone wet through
-
Thanks gents. I have taken the top cover off, put some good cam lubricant on the mating surfaces and put it back on with the bolts toward the lower end of the recommended torque to avoid pinching the cam hard and it's much better. Probably just how it should be. I can get all 5 gears too so looks as though I may have got the assembly OK. Had a potential disaster in that I'd obviously not got the circlip on the end of the kick starter shaft in properly and as I was doing the above turnover all the springs and gears came off the shaft into the sump. Luckily just managed to reassemble it with the bike on the side via the sump.
-
Had a potential disaster in that I'd obviously not got the circlip on the end of the kick starter shaft in properly and as I was doing the above turnover all the springs and gears came off the shaft into the sump. Luckily just managed to reassemble it with the bike on the side via the sump.
I had exactly the same thing happen to my CB550 yesterday. Had just fitted the kick start lever and Graham pushed down on it (it's on the workbench still on an engine stand) the kick start went down (yes, Graham can get the kick start down by hand on a newly rebuilt 550 ::) ::) ::))and, clatter, clatter, we heard a load of bits fall into the sump. Turned engine over onto her back, took sump pan off and the little circlip on the end had fallen off along with some other bits on the shaft. Easily rectified by putting all the bits back on and securing the circlip with some retaining gluey stuff just to make sure it doesn't come off again. If the engine had been in the frame and full of oil, I doubt we would have heard the clattering on the first kick !!!