Camshaft Top End Rattle

[Nessism]

Hi Don,

That pin hole in the cylinder wall doesn't look good, although I'm not sure how serious it is. I'd take a very close look at the rings in that hole to see if you can tell if they are hanging up. Also, have you pulled the valves out of the head yet? I'd do so to make sure none got bent from the cam chain episode. It's possible you have just enough bend to cause noise, but not leak. Again, just thinking out loud... Hope you find the problem.

Ian, funny thing was when I pulled the oil pump apart to clean it out, there was nothing to clean out. It was as clean as a whistle. No debris at all. And from my reckoning the oil gets sucked from the sump straight through the oil pump before going to the filter.very strange. Looks like I may have been chasing my tail.

Good observation about the exhaust leak. i saw that but thought nothing of it.

I have also wondered about the misalighnment of the primary crank gear and the clutch basket gear and wondered about how to correc the misalignment. But have not been able to work it out and the motor seems to operate OK without any real probs.

A picture for those that don't know what we are talking about.





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[49er]

Don, shame you haven't found anything defining the cause of that noise. It has given you a chance to review everything though and make some minor changes.

It's a good bet that the ali material has been removed when the cam chain was flailing around without tension.

I just looked again at your other post on reusing your head gasket. The pic there of the head shows that you had a leaking flange gasket on #3 exhaust, enough to stain the ali surrounding that port. The sounds on your your early video clips indicated that the engine noise was more pronounced near the #3 header.

I wasn't aware that the 550 cranks were fitted with straight cut primary gears. Some of your engine noise may be a result of this feature. The meshing of the driven gear with the crank gear, shows that they mesh off center. This may cause extra noise too!

Even if you can't completely eliminate the noise, you'll sleep easier knowing it won't be terminal for your engine.

Motor Checked, Cases back together

The crankcases have been split, the crankshaft, gear shafts have been removed and no wear marks have been discovered. Have taken the grinder to some parts in the crankcase to ensure enough clearance exists.

I found this when checking the cylinders in #4 cylinder, what do you think. It is a pinhole in the cylinder bore.




This picture shows score marks in the clutch cover but they appear to be running the wrong way.





These grind marks are between the two bearings adjacent to #1 cylinder. I think they are factory marks. I still need to check the clearance here now that the crank is back in place and the cases buttoned up again.





When riding the bike on the road I found it extremely hard to find neutral so I checked out the spring for the detent and found that it was extremely weak compared to a similar item off a GS650 motor, so I swapped them around. Hopefully find neutral a bit easier now. Old spring on the right, new spring on the left.





I also filed down the heads of the screws holding the oil baffles in place in the lower crankcase half to provide more clearance.





Crankcase ready to go back together.





Crankcases back together.





Now for the tedious task of fitting the cylinders back on the pistons.

Ah Well here goes again. Hopefully won't break any rings this time.

cheers.

[Nessism]

I have lifted the crank out of the top case after removing the pistons. Spun each main and conrod and no perceptible play and all turn smoothly.

Ed what do you mean by the clutch hub, is that the basket?

Yes, the clutch basket. It's an assembly with springs to reduce shock loads input to the transmission. On the larger bikes the springs develop slack or can even break which causes noise at low speed. Just grasping at straws here, trying to give you more things to check. Hope you figure it out.

I'm really interested in findin out whats the cause of the noise. I've got the same noise on my 850 and my 650 started making a similar noise. Have you made any headway?

Sorry you didn't find the smoking gun Don.

Looks like those metal flakes came from the cam cover, when the cam chain was flopping around. Kind of back to the beginning about the noise though. Did you turn each crank bearing and rod to check for smoothness? At this point I'd go though every single part as you build the engine back up, to make sure you didn't miss anything the first time. Another thing to check is the clutch hub since they like to make noise at low speed.

I have lifted the crank out of the top case after removing the pistons. Spun each main and conrod and no perceptible play and all turn smoothly.

Ed what do you mean by the clutch hub, is that the basket?

[Nessism]

Sorry you didn't find the smoking gun Don.

Looks like those metal flakes came from the cam cover, when the cam chain was flopping around. Kind of back to the beginning about the noise though. Did you turn each crank bearing and rod to check for smoothness? At this point I'd go though every single part as you build the engine back up, to make sure you didn't miss anything the first time. Another thing to check is the clutch hub since they like to make noise at low speed.

Regarding not finding anything so far, one way or another your engine is spitting out lots of shrapnel and you need to keep disassembling until you fine the problem. If the top end looks good the problem has to be on the bottom end.

Well, the cases are split and still nothing.








Any other suggestions?


P.S. Any suggestions what to get the 3M sealant between the cases off with quickly? Can't use gasket remover as it will lift the paint on the cases.

Billy, I will check when I have the head apart for loose guides, collets, and good sealing of the valves in the head for any leakage and will check the valve guide seals for damage before replacing them. The bike was not blowing any smoke in the 100 miles I covered on it after the first rebuild. So probably the seals are OK.

The bike also had plenty of power (probably due to my first ever cam degreeing exercise), and this would not have been the case if a valve collet was not in place or the valves were not sealing correctly. Anyway all these things will be checked when the head is disassembled.

Thanks everyone for all the good ideas, it keeps my head ticking over with ideas to consider when trying to fathom this problem out.

I do have another head I can have the machinist hot tank and reface the seats to replace the existing one if it all goes back together and ends up with the same problems. The head on it now is a Series I and the replacement would be a Series II.

Also thought I might check the cams clearance in the head while the head is disassembled. Mount the cams in place with the cam caps torqued to spec. And with a dial gauge check if there is any up and down movement that might be causing a knocking sound. Can't be done with the valves in place as the spring pressure is always pushing the cam upwards and cannot get a good measurement.

EDIT: P.S. I had planned to pull the oil pump apart to check for any debris in there.

Does the oil go through the pump before it reaches the filter?

Yes it does, so plan on disassembling the pump for inspection and cleaning. If it were me, I would split the cases and clean everything. Even if the problem is found elsewhere. The engine seals are reusable (just rotate them) and it will only cost you some time and case sealer....Billy

Billy, I have all new valves in the head and the head was done up by a local machine shop owned by a Harley rider (but we won't hold that against him). He faced the valves seats for me and fitted the valves and tested for leakage. I assembled the head myself with new valve guide seals. I had the valve stems faced off to provide clearance for the buckets, shims. The only thing I did not do was replace the valve guides.

The valve seals were not Geniune Suzuki Parts (GSP), but from a kit I bought on Ebay. The head gasket was Geniune Suzuki.

What sort of problem would I be looking for in the head that would cause this noise/issue?

Hey Don, What you would be looking for is a possible valve guide that has come loose in the head or anything that could have beat up a valve seal. Were the seals black, like the debris ??....Sticking with the fact that the problem is more evident with a fully warmed up motor, the cylinder head, which gets the most heat, seems a good place to carefully inspect.....Billy

Thanks Wally, I pull the motor from the frame tomorrow and split the crankcases probably Monday as I have some time off from work next week. The only thing I have not been able to check up to this point is the inside of the crankcase for score marks and the transmission shafts.

Then I plan to disassemble the head and check things out in there and replace the after market valve guide seals with genuine.

If I don't find any marks inside the motor where the aluminium scraps came from then I don't know what I'll do. It's like someone just threw a handful of shrapnel into the crankcase oil filler. The only place it has been found to this point is in the oil filter and lying in the bottom of the sump.

BTW another good suggestion from you on the valve collets, will definitely check that when I get the head apart.

[hampshirehog]

Billy got me thinking again (always dangerous). Maybe a cotter or two jumped out and is sat under one of your valve buckets?

Nothing yet

Well I pulled the generator cover, starter reduction gear, clutch, oil pump, etc. and have found no evidence of scored aluminium cases or any more debris.

Does the oil go through the pump before it reaches the filter?