Topic: Engine Suspicions

[rb550four]

  I've been here for a while. Have heard all kinds of ways to free a really stuck engine after years of sitting out in not some of the best conditions.
   It has occurred to me on more than a few occasions that once broke free, that some owners would run it. Not for just a little while, but run it until they think the inside is clean. Am I right in suspecting that this actually happens?
   I've seen the "Ran it til the smoke cleared up" or "it took a couple months to get the smoke to clear and the rings to get loosened up enough to seal". in threads before and thought surely these engines must have been broken down, cleaned out, at least honed and re-ringed. I thought someone must have been kidding. Lately I've been thinking breakdown doesn't happen as much as I think, could that be true?
   I ask because every motor that comes in my garage gets torn down once it's free. I've found most every ring is compressed and rusted tight to the piston and usually rusted to the cylinder walls, that in all cases require a hone or a bore. Most times it takes some real careful work to get the rings off and sometimes they don't come off. Half the valves are usually stuck in either open or an un-sealable positions and will  require at least a good cleaning and oiling and in most cases a light lapping just to be sure they will seal on their own. Cases are always split, rust and clutch dust removed, parts inspected,chains replaced, oiled while assembled, cylinders honed, rings gaskets and clutch... because that's the way it's done. It's all lots of fun  and I know what I got in the end, I 've never done it any other way. I treat these engines like I would a truck engine, that's the way I was taught and can hardly believe that there is any another way to do it that could skip any one of these steps.
  It  could quite possibly be just in my mind but,I think I've understood some threads as just cleaning the carbs and using the motor oil as a douche to clean up the rest of the problems....just drain it in 100 miles?.....well, I just don't know....  this idea is so foreign to me  that I can't understand why those motors would stay running for any period of time without further damage.
  This is only a reality check for myself. I need to know what the rest of the world is doing, definitely not trying to belittle anyone or their style of build...  maybe I'm not reading deep enough into some threads or some things automatically happen and deserves no discussion or pictures... I don't know  but, does what I suspect  really happen?
 
   

[dave500]

my thoughts exactly,if its been stuck its got to come apart,i wouldnt be happy otherwise,ive also found terrible internals like you describe.

[bill440cars]

  I agree, if it's stuck, I'm going into it and see just what's going on in there. It actually doesn't take much to stick an engine. But, I will check and do whatever it takes, to get it going again, if it's worth it.   

[seanbarney41]

disagree, and have several bikes to prove it.  Obviously, an engine that sat out in a bush on the top of a hill next to a river for 30 years is totally different from an engine that has one stuck ring from 5 years in a damp basement or garage.  They both won't turn over when you get them, the only difference is the magnitude of the internal damage.  The only way to see how much damage there really is, is to tear it down.  As soon as you pop that head off, you are into it, at least for $150 gasket kit...you better believe I'm gonna ride the #$%*er until it is noticeably lacking power, or making bad noises, or using impractical amounts of oil.  If these were as cheap to build as a chevy smallblock, I would probably have a different answer for you.  If it ain't broke, don't fix it.

[faux fiddy]

Fresh bored motors with new pistons are a nice starting point. 


I figure of  my 450s, I will split and  build the one that's worst off. That would be the one that is stuck and has the shift lever welded on, so it will involve some additional  effort to split the cases.

[MoMo]

I have done it both ways, and not had a problem.  All depends on the customers budget as to what I do, Larry

[tomkimberly]

That many of these bikes are able to start and run after un-sticking gives much credence to the original Honda designs.

That being said, for myself, if it's stuck it gets a complete rebuild.


Tom

[faux fiddy]

I have done it both ways, and not had a problem.  All depends on the customers budget as to what I do, Larry

I figure if there's any chance of the running when parked stuff that spins over I'll save it for later and fix the parts motor.

I was able to spend a weekend at Barber swap meet with about $400 and got a 'dixie' brand NOS piston kid 1.0mm over, wrist pins rings and all for well under $100. And I forget what the 'complete' gasket set was. Probably I need several seals and a shift shaft and lever for sure for the cl.  The tortion bar valve parts are a hard item to find. I never projected a budget but looked at anything that worked with the cl450  or 350f.  I  Should have bought the NOS fenders in the wrapper to resale  fund a motor. It changes a bunch what you find  each year, but one guy has a thirty year penchant for the twins. 

[fmctm1sw]

I've actually been very unlucky with unsticking them.  Therefore, all the stuck ones have had to come apart.

[faux fiddy]

I found this thread after years. I have one of my 450's and the motor was never stuck and always turns over. It has sat for over a year and I believe the rings have stuck into the grooves.

It has spark, valves are adjusted but because it turns over so easy it makes me believe the rings are stuck in the groove. Again, never any problem turning it over.  I haven't done a compression check on it, but probably if it is  ring (s) stuck  in the groove it would be a reason why it turns over so easy as if low compression.

Anyone got any ideas for loosening it up? I started with PB and liquid wrench, will do ATF and acetone. What else other than tearing into it?

It ran fine, was doing the hiway  speed limit when a plug shot out. I limped it home and parked it and now apparently no compression.

Any suggestions? Tow it until it pops and hopes it runs until hot and then loosens up?

I was  thinking take it to the next race and borrow some rollers to start it...Anything but have to tear into it,it ran fine and doesn't even leak.

[chewbacca5000]

What do you mean the plug shot out?  I use Kroil to try to loosen rings.

I have found there are several levels of "stuck".  On the 450 you have to have a cam chain tool which sucks imo.  You could also try just doing the 3,000 mile tune up.  Could be a valve or something simple.

Partially stuck rings will pop out with some heat and running.  Fully stuck in their groves will need a teardown.


As far as freeing totally stuck engines.  The piston position matters.  Ideally 2,3 will be on the bottom.

Severe rust is a deal breaker.  You are better off disconnecting the rods and save the jugs.  New bolts will cost $70 and is the easiest path for a total rebuild.

[faux fiddy]

What do you mean the plug shot out?  I use Kroil to try to loosen rings.


Partially stuck rings will pop out with some heat and running.  Fully stuck in their groves will need a teardown.


As far as freeing totally stuck engines.  The piston position matters.  Ideally 2,3 will be on the bottom.

Severe rust is a deal breaker.  You are better off disconnecting the rods and save the jugs.  New bolts will cost $70 and is the easiest path for a total rebuild.

I've got a complete stuck motor with new pistons chain and gaskets but I don't have time to tear down right now and I have to focus my studies on #$%*ry right now. Even though I have entered a default judgment in my favor, I have to defend a kamakazi attack this Monday in court and who knows how long after that before we're done.

I was on I-35 when the spark plug rattled loose and blew out, and I rode home in about 7 miles in limp mode. It was towards the end of the season and the bike needed other maintenance so I swapped the insurance to the other one. Now it's got new tires and sprockets but from just the "short"  time  it seems like a ring must be stuck on the piston.  It just kicks over too easy and no pop at all. Plenty of spark from coils off a running bike.

I adjusted the valves according to what team Hanson specified on twins.net, It's always worked before but I will sure check that again before any head comes off.