Camshaft Top End Rattle

[tkent02]

Neither rings or cylinders are aluminum, something else is going on here. Pretty large chunks it looks like. WTF?

 

[hampshirehog]

As it only makes the noise on tickover I'd still be looking at the cam chain (when it's 'slack' and not being pulled tight by the motor spinning fast). Maybe it's catching in the rear tunnel or down at the bottom end. I can't remember - did you use the original 550 bottom end or are you running a bigger sprocket down there? Plus did you double check that the front guide slotted in properly at the bottom?

 

[Suzuki_Don]

As it only makes the noise on tickover I'd still be looking at the cam chain (when it's 'slack' and not being pulled tight by the motor spinning fast). Maybe it's catching in the rear tunnel or down at the bottom end. I can't remember - did you use the original 550 bottom end or are you running a bigger sprocket down there? Plus did you double check that the front guide slotted in properly at the bottom?

Wally, The bottom end is original 550 suzuki, the bottom sprocket is cast on the crank and is the same at 15 teeth. I did replace both of the traansmission shafts and the selector forks, but everything else in the lower half of the crankcase is original except for new seals and gearbox sprocket. The only stuff I changed were the pistons, cylinders, head, cams, and carbs. I think the front guide is in correctly as it is held in place at the top by the valve cover and it is all the way down and flush with the top surface of the head.

 

[49er]

Don, that's a lot of ali in your oil. If you can eliminate the possibility that particles dropped down into the crankcase when fitting the bigger jugs to the 550 cases, then it's time you started pulling it back down.

The pics of ali show thin particles, probably consistent with the cam chain making contact somewhere.

I'd drop the sump cover and check for more particles in this area. If there's more in there, it's a fair indication that they are coming from above, not the clutch or starter clutch areas.

You may be able to check that the rear chain guide is fitted properly too. I don't know how they're located on the 550's, but it's not possible to fit the jugs in place on the 850's unless the guide is bolted in correctly. If this is the problem area, you will need to pull the jugs again to remedy the fault.

 

[49er]

The bottom end is original 550 suzuki, the bottom sprocket is cast on the crank and is the same at 15 teeth. I did replace both of the traansmission shafts and the selector forks, but everything else in the lower half of the crankcase is original except for new seals and gearbox sprocket. The only stuff I changed was the pistons, cylinders, head, cams, and carbs. I think the front guide is in correctly as it is held in place at the top by the valve cover and it is all the way down and flush with the top surface of the head.

Don, just saw this.

I'm now picking that your problem will be in the replacement of the transmission shafts. The series of washers/spacers on each shaft control their endfloat and correct gear messing positions. If the clearances at too tight, you will get the sort of temperature related symptoms after the warm up period. Without the correct clearances, ali will have been shaved off the case housings.

If you check the Alpha schematics, you'll see that the spacer washers are listed with a series of letters after the part numbers. These letters represent the range of thicknesses available at rebuild time.

 

[Suzuki_Don]

Don, that's a lot of ali in your oil. If you can eliminate the possibility that particles dropped down into the crankcase when fitting the bigger jugs to the 550 cases, then it's time you started pulling it back down.

The pics of ali show thin particles, probably consistent with the cam chain making contact somewhere.

I'd drop the sump cover and check for more particles in this area. If there's more in there, it's a fair indication that they are coming from above, not the clutch or starter clutch areas.

You may be able to check that the rear chain guide is fitted properly too. I don't know how they're located on the 550's, but it's not possible to fit the jugs in place on the 850's unless the guide is bolted in correctly. If this is the problem area, you will need to pull the jugs again to remedy the fault.

Ian, I split the cases to rid the engine of all aluminium particles that were the product of the grinding process when fitting the barrells. Washed everything out a number of times, including both crankcase halves, crankshaft and all other associated bits. So there would be no debris from there.

I plan to drop the sump cover and check in there as well. I removed the headers tonight as they prevent the removal of the sump cover. And will remove the sump tomorrow arvo.

The rear chain guide is fitted correctly as it bolts to the rear of the crankcase (same as 850), and both the guides, front and back prevent the chain from rubbing on the front and rear faces of the cylinder surfaces. But if the chain was out of alignment it could be possible for the sides of the chain to rub on the side of the cam chain tunnel. I will have to remove the head to check this out.

Also if you read earlier posts you would know that I had a cam chain tensioner problem and lost the large knurled knob and had to ride the bike a few kms with the cam chain slapping around. I posted pictures of the wear marks on the valve cover. I don't think the ali in the oil filter is from that experience, there seems to be too much of it. What are your thoughts?

 

[Suzuki_Don]

Don, just saw this.

I'm now picking that your problem will be in the replacement of the transmission shafts. The series of washers/spacers on each shaft control their endfloat and correct gear messing positions. If the clearances at too tight, you will get the sort of temperature related symptoms after the warm up period. Without the correct clearances, ali will have been shaved off the case housings.

If you check the Alpha schematics, you'll see that the spacer washers are listed with a series of letters after the part numbers. These letters represent the range of thicknesses available at rebuild time.

Ian, on both of my transmission shafts there is a large ball bearing pressed onto the shaft and the outer shell is located in the crankcase via a large "C" ring. So the way I look at it the shaft has no end play except for any clearance in the bearing, (C1, C2, etc). The only washers are thrust washers between the smaller roller bearings on the other end of the shaft and the adjacent gear and these do not appear to come in differing sizes. In fact there was nothing in the transmission fiche for my 550 that had a range different sizes. Can you check and clarify for me please?

 

[49er]

Ian, on both of my transmission shafts there is a large ball bearing pressed onto the shaft and the outer shell is located in the crankcase via a large "C" ring. So the way I look at it the shaft has no end play except for any clearance in the bearing, (C1, C2, etc). The only washers are thrust washers between the smaller roller bearings on the other end of the shaft and the adjacent gear and these do not appear to come in differing sizes. In fact there was nothing in the transmission fiche for my 550 that had a range different sizes. Can you check and clarify for me please?

My apologies Don. I've re-checked the 550 fiche and the washers had model number applications, not thickness ranges. All the transmission parts seem to have them.

It's possible that your cam chain could have left that much ali in the filter after the auto tensioner failed. The spare 850 head I'm working on has nice deep grooves in the cam chain tunnel from a PO's similar experience.
These grooves are around 2 mm deep each side. If you ran yours several kms with the tension slacked off, it's possible that the tunnel area is quite heavily grooved. Could be the source of all that ali. The chain will have received a bit of grief during that incident. But that still doesn't answer the "where's the knock coming from" question.

 

[Suzuki_Don]

My apologies Don. I've re-checked the 550 fiche and the washers had model number applications, not thickness ranges. All the transmission parts seem to have them.

It's possible that your cam chain could have left that much ali in the filter after the auto tensioner failed. The spare 850 head I'm working on has nice deep grooves in the cam chain tunnel from a PO's similar experience.
These grooves are around 2 mm deep each side. If you ran yours several kms with the tension slacked off, it's possible that the tunnel area is quite heavily grooved. Could be the source of all that ali. The chain will have received a bit of grief during that incident. But that still doesn't answer the "where's the knock coming from" question.

No need for apologies, I am appreciative of all advice given. I re-visited the pictures of the valve cover where the chain has been touching and the chain had only been kissing the valve cover surface. I think that there are more serious things happening inside my engine. Particularly after what I found when I dropped the sump last night.

I think the time for diagnosis is over. It's time to rip the engine apart again. My suspicion is that the problem is going to be in the cylinder head, barrel part of the engine. Another thing I intend to check is the width of the new heavy duty cam chain I purchased from Z1 just in case it is wider than the original and causing interference. There are some big flakes of aluminium coming off the inside of the engine.

 

[Nessism]

Keep your head up Don. I think you will fly second time though the engine since you now know every nut, bolt, shim etc.

Good luck and hope you figure it out.

 

[Suzuki_Don]

Keep your head up Don. I think you will fly second time though the engine since you now know every nut, bolt, shim etc.

Good luck and hope you figure it out.

Thanks Ed. I need that sort of encoragement. I have just come back from looking for a cliff to push it over.

The only thing I am really dreading is getting those cylinders back on. That was such a headache for me.

 

[Suzuki_Don]

Another short update.

I collected the debris from the sump cover and found that there were a few small pieces of rubber in amongst the aluminium shavings. I guess we can read: Bits of Cam Chain Blade/Guide.

After removing all the debris from the sump and seeing all the smaller bits of aluminium grit in the oil filter I was expecting to see this stuff all through the motor requiring a complete tear down again. I thought it would be through the crankshaft bearings, embedded in the clutch plates, transmission gears, etc.

This does not seem to be the case at the present time, who knows what I will find as I get deeper into the motor. I have removed the valve cover and the clutch cover and have found no evidence of debris in either of these areas.

I am halfway through getting the carbs off and then the head will be coming off after removing the cam chain tensioner and the camshafts.

Does anyone know if the rear cam chain guide can be removed without completely removing the cylinders. By lifting the cylinders enough to undo the bolt holding the rear guide in place and then lifting the guide up through the cam chain tunnel in the cylinders? So alleviating the neccessity of having to refit the cylinders over the pistons and rings again.

I am hoping that the aluminium cam chain guide that is screwed onto the lower crankcase half is not what has been chewed up by the cam chain as these are unavailable any more and it means splitting the cases again (a last resort).

 

[hampshirehog]

Don - have a go at removing that rear tensioner without pulling the cylinders but I don't think you'll do it.

If that thing has chewed up let us know. I'm pretty sure I've got a few decent ones kicking around you can have for nothing and I bet a few others on here have as well.

 

[Suzuki_Don]

Don - have a go at removing that rear tensioner without pulling the cylinders but I don't think you'll do it.

If that thing has chewed up let us know. I'm pretty sure I've got a few decent ones kicking around you can have for nothing and I bet a few others on here have as well.

Thanks Wally for the kind offer. I have the original somewhere as I put a newie in there when I rebuilt the motor. I will have to check on it's condition.

The thing I am really worried about is the bottom aluminium chain guide, I hope it's not all chewed up. If it is I have to find another (not an easy job) and split the cases again.

 

[Suzuki_Don]

So far i found absolutely nothing

So far i found absolutely nothing

OK I pulled the cams, head and cylinders tonight and so far have found absolutely nothing wrong. No scoring or marks on any aluminium surfaces. Not on the head, cylinders, or in the crankcase as far as I can see inside.

I was relieved though to note there was no evidence of aluminium bits around the crankshaft or around the cams and cylinder head. The oil filter did a pretty good job of filtering out all the foreign objects.

But I am still no closer to finding out where the ali debris came from and the knocking noise.

Next job will be to pull the motor from the frame and split the cases again and hope I can find something in there.

There was no damage of any kind to the chain guides.

The following link is to pictures of the condition of the head, cylinders, guides and crankcase.


http://s226.photobucket.com/albums/dd105/donclifton/Engine Teardown2/http://s226.photobucket.com/albums/dd105/donclifton/Engine Teardown2/


Any suggestions?


EDIT: I just had a thought that it would be a good idea to pull the clutch and oil pump and see if there is any debris in the oil pump and to see if I can see through into bottom of the crankcase under the crankshaft and look in there for other debris.


.

 

[Suzuki_Don]

Have been trying to fathom where the rubber pieces would have come from that were found in the sump with the aluminium debris. It does not appear to have come from the front or rear cam chain guides as they are both in excellent condition with no bits missing.

I can't think of anything else in the bottom end (around crank, transmission or clutch) that is made from rubber that could have released these rubber bits.

The rubber bits are the black bits in the picture. Only small but are definitely chunks of rubber.

The only other place I can think of where there are rubber backed bits are the two top cam chain guides. One in the valve cover and the other is an insert in the top of the head supporting the cam chain from underneath.

Any others suggestions?

I am getting the feeling I will split the cases again and find nothing and what do I do then? If the motor is still knocking and shearing off aluminium.

 

[Nessism]

How does your clutch basket look Don? Salty Monk's GS1000 had a clutch cover bolt sticking though too far and hitting the basket. 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.

 

[Suzuki_Don]

How does your clutch basket look Don? Salty Monk's GS1000 had a clutch cover bolt sticking though too far and hitting the basket. 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.

Thanks Ed. I was just thinking that there is no evidence of chips of ali in the base of the engine under the transmission gears and clutch basket, so maybe nothing is coming from that area. The only place I had not thought about so far was the generator housing and it's contents. Maybe that's an area to look at. There are a few cogs flying around in there that could cause some damage if contacting softer metals. I'd be sickened if it was something in there and I have pulled the top end off the motor.

 

[49er]

Don, most of those pieces look like ali that has been subjected to heat through friction. They appear to be very thin and irregular shaped.

I doubt that they have come from the clutch, but the starter clutch side??

I still think you'll find its expansion related, due to the noise appearing after the engine has reached normal running temps.

 

[Suzuki_Don]

QUESTION: What parts in the starter are spinning while the motor is running.