'75 CB550 locked up
- Thread starter Burr550
- Start date
you bent someting in the stator cover most likely so that it is pushing hard enough on the crank end to cause the problem stator rotor scrubbing against field coils
first thing to do is remove everything form the left side all the way down to the bare crankshaft end and check that for runout with a dial indicator
as you are taking it all apart look for the obvious damage,ditorted cracked case etc
first thing to do is remove everything form the left side all the way down to the bare crankshaft end and check that for runout with a dial indicator
as you are taking it all apart look for the obvious damage,ditorted cracked case etc
Hot500
New Member
Will the motor move at all? Even a little bit. Is the gear lever bent from the fall?
Its possible the gear selector shaft that runs across the transmission from the gear lever to behind the clutch basket has been dislodged and is now pushed into the back of the clutch basket jamming the transmission. There's not a lot of room back there and a fall onto the left side most probably impacted the gear lever in some way.
Put the bike in gear, pull in the clutch and try to move the bike. If the back wheel is locked up, so is the transmission. If it rolls OK, then its only the motor thats jammed.
Its possible the gear selector shaft that runs across the transmission from the gear lever to behind the clutch basket has been dislodged and is now pushed into the back of the clutch basket jamming the transmission. There's not a lot of room back there and a fall onto the left side most probably impacted the gear lever in some way.
Put the bike in gear, pull in the clutch and try to move the bike. If the back wheel is locked up, so is the transmission. If it rolls OK, then its only the motor thats jammed.
Burr550
New Member
The engine will not move. It bounced up off of the, still in parked position, kickstand and landed directly on the stator cover and foot peg. Gear shift lever is okay and bike will roll but I cannot put it in gear and push start the engine. We pushed the bike on my trailer to get it home then a day later I tried kick starting, not locked at that point, then tried the electric starter and it fired and ran good in the garage a minute before I shut it down. Next day I tried kick starter again, after about 3 attempts it just locked solid.
Hot500
New Member
OK, so Im a little confused. The bike would roll and start OK after the fall. The motor turned over at least three times when trying the kickstarter, then locked up.
So, have you tried the roll test after the lockup, because it still sounds to me you have a transmission lockup, not the motor.
I doesn't make sense that the motor would run OK, and then lock because you were using the kickstarter. My money is still on something jamming the trans. and the most likely thing is the clutch basket not being allowed to rotate causing a total lockup of everything.
So, have you tried the roll test after the lockup, because it still sounds to me you have a transmission lockup, not the motor.
I doesn't make sense that the motor would run OK, and then lock because you were using the kickstarter. My money is still on something jamming the trans. and the most likely thing is the clutch basket not being allowed to rotate causing a total lockup of everything.
Burr550
New Member
I don't know how or why (until I get it opened up) but the engine did not lock until the day after the wreck. Immediately after I got it back up I looked it over and tried to start it, I was uncertain how much damage was done so I just pushed it down the slope in gear and let the clutch out. Did not start but turned over a little on the slow down hill.
Got a helper to bring it home on a trailer then sat in the garage with it hating myself for awhile then tried kick starting to no avail. Came back a few hours later and kicked it again to start. Now I'm not as worried so call it a night, next morning no start and locks up on about the third try.
From recent posts, the stator is most quickly accessible so I'll start there.
Moved it out of the way then filled garage with lumber and siding, need to get that out of the way so I can go to work on it.
Got a helper to bring it home on a trailer then sat in the garage with it hating myself for awhile then tried kick starting to no avail. Came back a few hours later and kicked it again to start. Now I'm not as worried so call it a night, next morning no start and locks up on about the third try.
From recent posts, the stator is most quickly accessible so I'll start there.
Moved it out of the way then filled garage with lumber and siding, need to get that out of the way so I can go to work on it.
ok good work so far.take a file dress down the rotor untill it has no knurled-high spots
then look for high spots inside where it runs close to the field colis.
are any of the locating dowel/bushings fitting loose now? any cracks at the locating ponits ?
what you have is a pretty darn precision assembly with certain air gap that needs to be maintained concentrically even
look at where the field coil attaches inside the outer case for damage or shifted mounting points...
befor putting anything back together,try spinning over the engine( pull ot spark plugs) and look at the rotor :-/ if is bent or not running concentric you should be able to see it with the naked eye..better yet is a dial indicator just barely contacting the rotor and turn the mototor slow and observe any runout ...also you could use a felt pen sharpie/crayon/chalk to see the runout like checking a wheel fertrue
this is the stuff you should do first
it is possible that just a chunk o metal got knocked loose and wedged ,that is what locked it without damage to the precision alighnment of the mounted assembly this would be the good luck
try putting the case on and turning it over slow ,maye winde a couple layeres of electrical tape around the rotor then it will act as a witness,getting wadded up if the shits is whacked off center form each other
if you can get ait all back together like it should be you better check the charging cuase on some of the hondas like the cb900f a lil tipover and shit get shorted-out and the shit dont make elec-'tricity no mo
then look for high spots inside where it runs close to the field colis.
are any of the locating dowel/bushings fitting loose now? any cracks at the locating ponits ?
what you have is a pretty darn precision assembly with certain air gap that needs to be maintained concentrically even
look at where the field coil attaches inside the outer case for damage or shifted mounting points...
befor putting anything back together,try spinning over the engine( pull ot spark plugs) and look at the rotor :-/ if is bent or not running concentric you should be able to see it with the naked eye..better yet is a dial indicator just barely contacting the rotor and turn the mototor slow and observe any runout ...also you could use a felt pen sharpie/crayon/chalk to see the runout like checking a wheel fertrue
this is the stuff you should do first
it is possible that just a chunk o metal got knocked loose and wedged ,that is what locked it without damage to the precision alighnment of the mounted assembly this would be the good luck
try putting the case on and turning it over slow ,maye winde a couple layeres of electrical tape around the rotor then it will act as a witness,getting wadded up if the shits is whacked off center form each other
if you can get ait all back together like it should be you better check the charging cuase on some of the hondas like the cb900f a lil tipover and shit get shorted-out and the shit dont make elec-'tricity no mo
Burr550
New Member
Put the cover back on, the engine turns but as I push kick lever down with one hand I can feel, with my other hand on the cover, a point in rotation where there is rough contact/tightness somewhere inside. Tried tape on rotor, it did not wad up but did show contact. Pic does not reveal the marks well. Tested the field coil and stator, they are bad. I'll have a replacement this week.
