1985 GS550ES Knock When Hot

[Guest]

I have a 1985 GS550ES 16v. When the engine is cold it is dead quiet. But after it warms up it starts to knock more of a tick. I can feel the knock when I put a screw driver on the stator cover. Starter seems to work fine, does hang for a second after the engine starts through.

A little background, I did swap engines for a similar knock. The original engine was knocking again only when warm. I thought its it was rod knock due to the knock going away when unplugging the cylinder 1 spark plug wire. But this other engine is the exact same. I find it hard to believe that both engines have a worn cylinder 1 rod bearing.

Both engines have around 20k on them. Could it be the camshafts endplay like the 8v engines?

Any ideas?

[tom203]

Yes, seems strange for both engines... But humor me....if you use the kickstand,before your next cold start leave bike on centerstand,or propped up so oil is more level in crankcase before startup.

" starter does hang for a second after the engine starts through." Is the starterclutch sticking, or is the starter motor solenoid sticking "on"?

[Curtie94]

I think it's the starter clutch since the starter on the old engine didn't stick on.

I'm replacing the stator right now bike is on center stand so I'll let you know when I start it if it knocks.

[fbody_mike]

Swapped engines same noise..... are you sure it isn't an exhaust leak?

[Steve]

Make sure the starter clutch is tight against the back of the rotor.

.

[Curtie94]

I don't have the tools to pull the rotor. But I can't move the starter clutch by hand.

Any tricks to remove the rotor so I can check the bolts? I can get the bolt off with my impact

[tom203]

Ok, you got the bolt out, does your rotor have an internal thread? My 650 rotor has a 16-1.5 (?) internal thread. If so, get the right size and length bolt that screws in there and will push on end of crankshaft as your impact blasts away!

[Curtie94]

My rotor only has external threads. The service manual says to use a slide hammer with the correct adapter. The thread pitch looks to be 30mm x 1.5. I may try to order a puller with that thread pitch and see if I can make it work.

[tom203]

Something like this (with right size) is gentler than slide hammer fun. Try borrowing one, a local shop might have one

https://www.ebay.com/itm/1980-1982-SUZUKI-GS-1100E-1100-E-1983-1100ES-ES-G-FLYWHEEL-ROTOR-MAGNETO-PULLER/322546115460?epid=1744889838&hash=item4b193f2384%3Ag%3ANVIAAOxyjK1RB%7EGr&_sacat=10063&_nkw=1983+suzuki+gs1100+rotor&_from=R40&rt=nc

[Curtie94]

yeah I was looking at those on eBay. I may go see my local shop and see if I can borrow

[Curtie94]

So today i installed a 4 into 1 exhaust and used new gaskets.

I had the bike on the center stand during this, engine was cold.

I checked the oil level, and started the bike. Nice and quiet. Let the engine warm up for a minute still quiet. Went for a spin around town and I could start hearing the same tick. As the engine got hotter the tick got louder.

The tick gets faster with more rpm and doesn't go away. It almost sounds like valvetrain.

I can hear the tick just about anywhere on the engine and doesn't seem louder anywhere I check except for the stator cover.

My puller will be in tomorrow so I can check the starter clutch.

Anything else it could be? I checked and the timing chain tensioner is quiet.

Could it just be the valves being loose? I would think the valve lash would make noise when cold, not hot though.

[TxGSrider]

After the motor cooled off did the noise go away?

[Curtie94]

Yes on a cold start its quiet.

[TxGSrider]

Yes on a cold start its quiet.

Then it may be your valve lash is loose. They loosen up a little when they warm up... Your oil also thins out as it gets hotter which might cause the valve lash to make more noise.

[steve murdoch]

Did you change the exhaust gaskets when you installed the new pipes?
It MIGHT just be an exhaust leak.