81 GS750E garage rebuild thread...

[PsychoRallye]

Hi all-
I've only introduced myself here but thanks for all the warm welcomes. I figured it'd be fun to show my progress (or lack thereof lol) on the bike rebuild I'm doing over the next few months this winter on my newly acquired 1981 GS750E...

I don't yet have an actual vision for the bike other than reliable, looks like it should, and keep people asking "how old is that?" or "wow I haven't seen one of those since..." etc...

When I started the bike had some quirks:
One crash bar (left) had a stripped screw on the shared motor/frame mount hole...
The bike had issues starting when cold
The bike wouldn't idle property once warm unless you turned the air idle up a bunch
The bike's mileage wasn't great (but wasn't horrible either)
The tank has a minor dent
The front end makes an intermittent "whirring" noise (the best I can describe it which is regardless of road speed of the bike
The front fork/dampers are useless and have a seal leak
There is oil coming out of lots of places on the engine
There is some minor surface rust on lots of the chromed/coated parts
The mirror mount on the right side is stripped out
The throttle control rotates semi-freely over time on the right control
The choke cable sticks


Ok, not much for a 30 year old bike, eh?
To work! I took a photo or two before, and after a few hours on two consecutive days. I'll try to take photos more often...

Cheers all

 

[PsychoRallye]

Day 3, about 6 hours in

Day 3, about 6 hours in

Just the bottom end, trans and fork on... everything else is in baggies or boxes...
Personally I like how it's upside down. Hopefully most photos won't be

 

[PsychoRallye]

First small issue...

First small issue...

Is this normal wear & tear on the cam? I feel no grooving...

Oh, and the tach gear is annoyingly chewed up. The tach still worked fine on teardown... should I leave it alone? Replace the cam? Replace the gear to drive the cable? The cable itself? Could this be related to my front end whirring which is intermittent and appears to have nothing to do with road speed (I can't remember if it is related to engine speed in any way) -- but the noise DEFINITELY comes from the cluster area, not the engine... unless it works like the soup can radios

 

[Nessism]

Sorry to say but that tach gear is done for. Shouldn't be too hard to find a new one...although that model 750 has oiling system problems so maybe it will be. Hope not anyway.

Oh, and nice thread. You might want to up load your photos to photobucket.com or similar and then link the code here so the photos show up in high resolution.

Good luck and keep going...

 

[rapidray]

I just tore down a 750 engine & have a good exhaust cam if you need one. Ray.

 

[PsychoRallye]

Thanks guys for the feedback... so Ed, if there are known oiling issues with this engine, can I drill some additional feed holes or in any way redirect to get rid of the flow issues? Other than the tach gear being messed up a bit, it doesn't seem that there is any scoring, pitting or other wear (that I've seen yet anyway) anywhere in the engine...

Ray-
Thanks a bunch! I was about to post in the wanted section... let me know what you want for it and we'll go from there !

Justin

 

[81GS750]

cams from an 1100 will work too. I had the same problem with my tach gear. Same year and model bike as yours. I bought cams from a GSR member.

 

[MAdams450]

My 750 had the same whirring sound when I got it. We had to lube up the tach cable over and over and just clean everything we could until it freed up. May not be the same issue, but it's worth a shot.

 

[81GS750]

How is the build going? Any progress?

 

[Nessism]

Shimming the oil pump pressure relief spring is a popular fix for the oil system issues. Please do a search in the archives for more details on how much to shim.

 

[Hoosier Daddy]

Yes, How's it going?

 

[PsychoRallye]

Hi y'all... thanks for checking in on me! I've had almost no time, with the holidays and all... but some has been done. I will check into shimming the oil spring, great idea... The frame is now almost completely naked.. .but I don't think I have a tool that will pull that slotted nut (wrong name?) off the steering bearing stack... what can I make to do it or can I get one cheap somewhere? There is a photo in the album of the "nut" I'm talking about...

From there, the frame can go off to get cleaned and painted... maybe powdercoat?

Anyone know of any places in the greater NYC area which will do media blasting and/or soda/sand blasting to clean all the irregular surfaces? Or alternatively, anyone know of a good place to go get a relatively inexpensive media blasting cabinet & system so I can do it myself, either as a rental or purchased?

GS750EX Restoration photo album

 

[Texas Don]

You need an adjustable spanner. I picked up one off flea bay for $6.99 including shipping. Go for an older one, not a new one. These wrenches rarely fail because they really don't see much use anymore. The proper size is 3/4 to 1 1/2 inch.
Don

 

[Bimota SB4s]

Sometimes a schock absorber preload ajustment tool will do it.

 

[PsychoRallye]

Just ordered some replacement stuff from Babbitt's - I guess we'll see how they do on availability

New Athena gasket set is here... does anyone have a suggestion on better head gaskets ? Or valve cover gaskets for that matter... They don't look "bad" but they are just that paper stuff with some metal on the head gasket...

Thanks...

 

[Hoosier Daddy]

I am a relative "Noob" here but have already read numerous posts to use OEM (Suzuki) Head and base gskts for their reliability.

 

[81GS750]

OEM Suzuki gaskets all around. I'll use aftermarket on the valve cover though.

 

[DanTheMan]

Use RealGasket on the valve cover. BassCliff's welcome has the link for it. It's silicone and can be used over and over again without leakage.

 

[Larry D]

Use RealGasket on the valve cover. BassCliff's welcome has the link for it. It's silicone and can be used over and over again without leakage.

NO !!!!!!!!

DO NOT use a RealGasket on an engine that has the tach gear in the valve cover !!!! A 16V 750 is such an engine !!!!

The added thickness of the RealGasket prevents the gears of the tach from meshing properly and will eat it up in no time.

 

[PsychoRallye]

Should I just make my own gasket using a thin bead of RTV or use the Athena one then? Interesting that it negatively affects the mesh of the tach gear -which makes sense... but I would not have thought of it. Sounds like personal experience

Oh, and what's your thoughts on gasket sealer or some other lubricant or adhesive or sealant on the various engine gaskets... I've heard differing schools of thought on automotive (read: car) applications depending upon the gasket... experience/thoughts?

Thanks guys...