Camshaft Top End Rattle

[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.

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?

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?

[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.

[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.

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.

[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?

[tkent02]

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

Thanks Ed for the suggestion. It is something I can check as I have the old 550 and another set of 650 cylinders so can take measurements off both and compare.

I drained the oil last night to be able to check in the clutch area for any looseness from the clutch basket, etc. I found a fair amount of particles in the oil filter when I removed it. The particles all seem to be aluminium.

So what opinions do you have? Is this amount of particles normal for a rebuilt engine on first oil change or excessive and the result of the knocking noise inside the motor. The only bedding in that was required was the rings and bore (I think), all the bearings in the motor were existing so were worn in.

Opinions please?






The aluminium particles are for the full length of the paper filter.








BTW the motor has only done 80 odd miles plus the running in the shed on startup and looking for this problem.


Thanks

I have used standard Suzuki pistons on 550 rods and a genuine Suzuki 650 head gasket. I will do the test as Billy says and if necessary remove the head if the results are negative....................

I think your suggestion of just running it until failure sounds more exciting than pulling head again. Unfortunately, I understand your frustration and desire to solve the problem, I spent a couple months playing with my 550 before I got it running correctly.

Is there any way that the connecting rods were interfering with the cylinder sleaves? I am sure you removed material in crankcase to fit sleaves, if the cylinder was slightly positioned too far forward or aft is it possible that you have a clearance issue with rods? I don't know how you would check this but it may make this knocking noise in the lower end. Really just guessing and most likely way off base as usual.

BBB, that's a good call about the piston hitting the head gasket.

That scenario is certainly possible after mismatching components. It could fit the symptoms of the noise only surfacing once the engine has reached running temperature too. The resulting expansion could cause the piston to protrude slightly out of the hole, while the gasket edge expands into the bore.

I have used standard Suzuki pistons on 550 rods and a genuine Suzuki 650 head gasket. I will do the test as Billy says and if necessary remove the head if the results are negative....................

Hey there Don, just re-read this whole thread and this just has to be resolved. Are you using a stock or manual cam chain tensioner.???....If you are using a stock one maybe try reloading and setting the tensioner with the valve cover on....Or did you already do it this way ??...The noise sounds more deep than I would expect from a top end noise. Try pulling one spark plug at a time with the motor running and see if the noise changes more notably on a certain cylinder (use insulated pliers for this). Is it possible a piston is nicking the compressed portion of the head gasket. If it is the "cadence" will typically double in frequency when you pull the right plug wire.....Keep pluggin away, Its probably conversion related....Billy

Hey thanks Billy for the reply. Yeh I agree this has to be resolved. I am not far from either giving up or just riding the bike and waiting for it to get worse and eventually something will fail and I will know what it is.

I am using the stock cam chain tensioner which has been completely rebuilt as per BWRINGER's instructions. I did fit the tensioner before fitting the valve cover, but remember I did lose the large spring and knurled knob and lost all the tension on the chain and had to ride it home with the tensioner not working. If I was to remove the tensioner and reload it I would have to remove the carbs and a lot of other stuff to do it. Remember the 550 frames are a bit smaller than the frames for the larger bikes and everything is very tight.

A good idea to pull the spark plug wires in turn to look for change in noise. I will try that when I get a chance.

Thanks for all your helpful comments Billy.

[49er]

BBB, that's a good call about the piston hitting the head gasket.

That scenario is certainly possible after mismatching components. It could fit the symptoms of the noise only surfacing once the engine has reached running temperature too. The resulting expansion could cause the piston to protrude slightly out of the hole, while the gasket edge expands into the bore.

Is your exhaust sounding good & your valves set right? My 750 was making a top end rattle (sounded like a really loose valve) & I figured one of the adjusters had come loose......

Turns out 3 or 4 valves were out of tolerance at 0.2mm (spec is 0.09 - 0.13mm on this bike) plus a loose exhaust header which was amplifying the noise (I needed to snug up all bolts, I'd actually lost a couple too).

Dan

Thanks Dan for your comments. I had just tightened the header bolts before I took the video so i know they are OK.

And I had just checked the valve clearances before refitting the valve cover and then removing the tacho gear. They were as follows:

Exhaust:
1 (0.10), 2 (0.07), 3 (0.09), 4 (0.08)

Intake:
1 (0.08), 2 (0.08), 3 (0.10), 4 (0.08)


I like the clearances a bit on the loose side, particularly with a rebuilt motor as things will settle down a bit and the clearances will probably close up a bit.

thanks again Dan for the advice.

Hey there Don, just re-read this whole thread and this just has to be resolved. Are you using a stock or manual cam chain tensioner.???....If you are using a stock one maybe try reloading and setting the tensioner with the valve cover on....Or did you already do it this way ??...The noise sounds more deep than I would expect from a top end noise. Try pulling one spark plug at a time with the motor running and see if the noise changes more notably on a certain cylinder (use insulated pliers for this). Is it possible a piston is nicking the compressed portion of the head gasket. If it is the "cadence" will typically double in frequency when you pull the right plug wire.....Keep pluggin away, Its probably conversion related....Billy