Tensioner rattle

[gs750e]

Hello GS resources,

My 1978 GS750 is making a rattling noise when running stationary at 2100 rpm and continues to do so from there on in the rev range. When I looked under the right-hand side of the tank I noticed the end of the cam tensioner was vibrating. So the tensioner itself is creating the noise, also there is not a lot of pressure on the spring I think. Who knows what to do? Here is a picture: http://img705.imageshack.us/img705/7439/ccty.jpg

Thanks,
Jim

[Nessism]

Sounds like time to pull the tensioner and make sure it's working properly. This may help...http://www.bwringer.com/gs/camchaintens.html

I suggest removing the valve cover and putting the engine at 1-4 T (TDC) before removing the tensioner. After reinstalling, and releasing the set screw, double check cam timing before turning over the engine.

Needless to say, you might want to check/adjust the valves while you have the cover off. Please tell us you believe in maintenance rather than waiting for the bike to falter before doing anything.

Good luck.

[gs750e]

Allright, this was the answer I was hoping for. So I'm ordering a new head gasket and tensioner gasket, and a good second hand tensioner. And when the head is off I'm gonna check the valves. Am I missing something that I have to replace when the head goes off?
Thanks for your input,
Jim

[azr]

No need to buy a second hand tensioner, you just clean and rebuild the one you have. If you look at the link Ed posted earlier it shows you how to do it. And just so you don't get mixed up when ordering your parts, you are not buying a head gasket, you are buying a valve cover gasket.

[Nessism]

EDIT: azr posted while I was typing...

Jim,
You need a valve cover gasket, not a head gasket. Do not remove the head. Remove the valve cover.

Going through that used tensioner and refreshing the seals sounds like a good idea. That way you can keep using the bike and then just swap out the refreshed tensioner for the old one with minimal down time. Of course, you can rebuild the old tensioner too. Just don't buy a used tensioner and install it as is. Go through one or the other and make sure everything is in proper working order before you install it.

[gs750e]

Alright guys thanks a lot, much appreciated

[gs750e]

Oh yeah, I red somewhere that you can also use a tie-wrap to hold down the chain, instead of setting the timing to TDC. Like this :

http://byfiles.storage.msn.com/x1pGHpas_o48llbuchw4yeq28EMpjyCNJgcjfhTDK2jOPBKIU4ZQ-lYd-drTGKWgthh9jmUtKgYv4uZjew6QEU1mdqvoRk5NJr589WF-VVcvelojQD0izJ2-OB6CHsw_mZM3egb8u-W4t9YjcRgDR-SP_uVagRkX5U4

Is this a good idea? Asking this because I've never adjusted the ignition timing before, and this seems foolproof

[gs750e]

A little update:

I Rebuild the cct, adjusted the valve clearances, replaced the ignition points and staticly adjusted the ignition, changed the air filter, put stainless brake lines on her, revised the calipers, renewed some gaskets, polished the cam chain cover, replaced the cam end seals, had new front fork seals put in, installed a new turn signal relay, brake pads, chain and sprockets, sporty handlebars and I painted some stuff.
The GS starts way easier, runs stationary at 1500 rpm instead of 2100 to keep it from randomly stalling, and there are no rattles coming from the engine. Next is synching the carbs and getting the ignition set up with a stroboscope. I learned a lot, thanks for the help.

Some pics:



DIY carb syncher:

[tkent02]

The GS starts way easier, runs stationary at 1500 rpm instead of 2100 to keep it from randomly stalling, and there are no rattles coming from the engine.

You are getting closer. The correct idle is around 1100 RPM, but it should be able to idle down to about 500 - 600 if it is all working well. You might look for air leaking around the intake system someplace, or some partial clogging or other problem in one or more of the carburetors besides just synching them.

[gs750e]

You are getting closer. The correct idle is around 1100 RPM, but it should be able to idle down to about 500 - 600 if it is all working well. You might look for air leaking around the intake system someplace, or some partial clogging or other problem in one or more of the carburetors besides just synching them.

Oh alright, I'll set it to 1100 as soon as I warm it up all the way. The first ride is gonna be a very short one to the shop where they have the stroboscope to adjust the ignition properly. Don't want to risk running the GS lean for too long.

[Steve]

Setting the idle to 1100 RPM will not make it run lean.

.

[gs750e]

Setting the idle to 1100 RPM will not make it run lean.

.

Sorry what I meant: I have only set up the ignition staticly, I heard that adjusting without a stroboscope is not precise enough and that the ignition will aways be a little early, so the bike will run lean. I only made a short testride with it for this reason, so the choke hasn't even come off, I will adjust the idle to 1100 when I warm the bike up on a longer testride.

[Steve]

, I heard that adjusting without a stroboscope is not precise enough and that the ignition will aways be a little early, so the bike will run lean.

Changing ignition timing won't make it run lean, either.

Setting your timing without a strobe can actually go either way.

To make it run lean, you need to add more air without adding more fuel.
Either air leaks or not changing the jets when you add a header or pods wiill make it run lean.

.

[gs750e]

Oh nice, then I don't have to visit a shop. I'm just gonna make sure the air filter is clean, there are no leaks and work with the carb settings and jets from there, thanks.

[koolaid_kid]

You will eventually want to put a timing light on it to fine tune the ignition timing, but it is not imperative that you do this immediately.