Dyna-S ignition system (now cam end float thread)

[royhall]

Thanks guys. Sawdust in the gearbox, I had forgotten about those stunts.   Not too sure where i'm going with this to be honest. As the knock is only present when the engine is warmed up shouldn't I be going for a heavier oil not lighter to stop the knock. I've strayed into a subject here that I know absolutely nothing about.

[royhall]

Had another word with the MOT guy over a pint last night. This is the oil he's talking about, reasonable price as well. What's the verdict guys.   https://www.ebay.co.uk/itm/Quality-German-Fuchs-Titan-HD-Universal-15w-40-Oil-5LTR-15w-40-/122808657692?_trksid=p2385738.m4383.l4275.c10

[kevski]

But is it wet clutch compatible?

[Bryanj]

That is what used to be transfleet oil and is all i ever use, but i have still got 40 ltr of transfleet left!!

[royhall]

That is what used to be transfleet oil and is all i ever use, but i have still got 40 ltr of transfleet left!!

So you reckon the Fuchs Titan oil is good with the clutches Bryan?

[Bryanj]

All I can say is the Transfleet is fine and when i asked Silkolene now Fuchs they told me the Titan was the replacement, nowhere does it say it is synthetic so it should be OK. You can still get Tesco Mineral oil from petrol station forecourts but not the stores for some reason

[royhall]

All I can say is the Transfleet is fine and when i asked Silkolene now Fuchs they told me the Titan was the replacement, nowhere does it say it is synthetic so it should be OK. You can still get Tesco Mineral oil from petrol station forecourts but not the stores for some reason

Thanks Bryan will give it a go. It's had a hone and new rings so will use use the 10w-40 oil thats in at the moment for a couple of hundred miles. I shall report back in Spring if this oil makes the cam knock go away.

[royhall]

Just a quick update. The oil change did not make a scrap of difference to the cam knock situation. Going to whip the cam cover off and have a little look.

[McCabe-Thiele (Ted)]

That oil in the  link is listed as Mineral - I used Fuchs Titan Unimax UltraMC 10W/40 in our old Jeep - trouble is its synthetic so could cause clutch issues.

Only thing I have used that has ever quitened an engine noise on an engine (Alfa Guiletta Sprint GT back in the 1960's) is Molybdenum Disuphide (Molyslip) it makes the oil more sticky - looks horid as it is black. It takes a good 15 minutes to circulate & coat everywhere  - in reality hides the problem so I doubt that would not suit you Roy.

[royhall]

The Fuchs Titan oil is fine with the clutch. I would be very reluctant to use a Molyslip type oil as that will cause clutch slip, if it was a dry clutch it would be going in right now. The cam end float on Suzuki GS is a very common problem and causes no engine damage long term, I was just trying to tone it down a bit.

I really don't like the idea of the so called repair in the above post. The reason the cap is stepped back from the cam is to allow the oil flow to lubricate the cam lobes as there are no drillings to do that job. On the "fix" you are making the end float bearing face continuous which then becomes pressure lubricated like a shell bearing and prevents end float, but it will starve the cam lobes of oil and eventually cause engine damage. I will have another look and check the cam chain pulley sideways action whilst I'm in there.

Shame really as it's the only problem on the bike. The thing is reliable, starts at the touch of the button, runs well and goes like stink, and also sounds awesome with the Delkevic 4 into 1.

[K2-K6]

Same here with molyslip,  view it as accumilative for clutch friction and should be avoided.

It'll be interesting to see what you can find regarding cam movement Roy when you have a look inside.

[K2-K6]

Just a thought Roy, categorized as "GS cam end float" are you certain of that and have you tried loading transmission with is held on rear brake to observe if if changes at all when pulling slightly?   

What I'm getting at is that it's assumed to be that stated reason,  but is there certainty in that diagnosis that's floating about?

[royhall]

You may be correct there. I shall try loading the engine and see if it stops.

The cam end float I have measured previously. It was 6 thou on the intake and 5 thou on the exhaust, roughly the same as the guy in the "fix" had measured. I measured this with the head removed and the camshafts just sitting in the head. I set up a DTI and whilst pushing the cam one way I zeroed the dial then took the reading pushing the other way. So the clearance is 2.5 to 3 thou per side. There are visible marks on the head surface where the cam has been running for 55,000 miles but you cannot feel any of them with a finger nail. I think that clearance is what Suzuki intended as when it heats up the steel cam will expand by more than the aluminium head. I would love to know what the clearance is meant to be but cannot find that information anywhere and nobody appears to know.

I think I may be looking for something else as I have just rebuilt the top end and it has been perfectly quite for 300 miles. The knock came on suddenly after a long hot run rather than a gradual increase. I used Graphogen compound on the cam bearing faces during the rebuild but I doubt any of that would still be in after 300 miles of hot running. The oil in it at present is Fuchs Titan 15W40. The clutch basket was rebuilt by Grumpy1260 with welded rivets (the usual Suzuki mod) so will check that is still tight, there was a new starter sprag clutch fitted so I will also check all that is still tight. I will take the cam cover off and re-check the shims as the valves were re-ground and the seats re-cut so they could have closed up. Also as mentioned earlier in the thread (although the GS1000 does not have tensioner wheels) I will have another look at all the cam chain parts (cam chain itself is new), plus the auto tensioner appears to be working okay.

Then after that I'm stuck. If I can get it quite enough I will part exchange it for a new 1200 Triumph Bonneville. Happy days.

[K2-K6]

"I used Graphogen compound on the cam bearing faces during the rebuild but I doubt any of that would still be in after 300 miles of hot running. "

Had a bit of a think while wandering around today 

That's really interesting. OK a speculative theory, the camshaft rotation of valve buckets I doubt they have used in that geometry as it requires thrust faces to resist. And so it must be running a non biased lobe to bucket geometry from original design with no attempt to turn the buckets for evening of wear characteristics.

But, and it's a big but, if through mileage it's created a wear pattern on one or more of the load faces such that it now tries to rotate that bucket,  then the contact point initially of the cam as it comes onto the static face will now attempt to prescribe an arc in spinning the bucket (still with me?) Which will shunt crossways load onto the camshaft to give longitudinal travel "knock" just as it flicks the camshaft left or right. 

This the graphogen may have prevented as that's what it's supposed to do. Now fully removed into the oil, including remnants in the surface texture,  it has seen a rise in stiction just sufficient to flick the cam.

Testing;- put some more graphogen on each cam load site and run it again to see if it improves.  Further action,  inspect all the buckets for flatness to see if you can observe any discrepancy.

[royhall]

I think I'm with that? The problem with the wear theory is that this is a shim over bucket design and all the shims are new giving a fresh flat face. I can easily check what wear is on the old shims that I took out. My first target when the top comes off is to check the new shims as there could be a faulty one not heat treated correctly or something. It will be a few weeks before I can open the engine up as I have house renovations to do now (on threat of castration if it doesn't happen).