1978 gs 750e cafe racer rebuild

[drivera84]

hi guys,

I took off the gauge cluster yesterday...it was broken. I like how it looks without it...is there any danger in leaving it off?

Not much progress in the engine...I keep on spraying it and adding diesel. I took off the crash guards and was going to take the engine guard off but the bolts were very rusty so I gave em a little squirt with penetrating oil before I try to remove them....luckily patience is on my side...

thanks!

[Hoosier Daddy]

....luckily patience is on my side...

Atta boy!
Slow and steady will win this race.

[verde]

hi guys,

I took off the gauge cluster yesterday...it was broken. I like how it looks without it...is there any danger in leaving it off?

Nope, I don't think losing track of the miles will hurt your resale value on this at all. A good electronic speedo will run you $100+, I just use a bicycle speedo:

http://www.aerostich.com/sigma-speedometer.html

Double check the threading if you have to go this route, but I believe it was a standard size M18 oil pan drain plug from the auto parts store I ground down to plug my leaky tach drive. (pull the unit off, push the drive shaft out, plug and reinstall. I had to grind the bolt shorter and take down the shoulder of the bolt to clear the cam chain bulge in the case. A little redneck, but if you do it cleanly it looks good. Maybe just special order a nicer looking bolt)

Awesome.

[TheCafeKid]

It's a good thing that the deal for the '80 750 motor fell through because it wouldn't have fit in that frame without mods. They're completely different motors/bikes.
When hunting for parts, be aware that 77-79 750s will all have compatable parts, while any 750 after 79 will likely have very few direct swap parts.

If you're hunting for a larger motor, a GS1000E motor will swap with some minor modification to the frame mounts but no other motor will be a direct bolt in besides a first gen 750 motor.

Good luck with your project.

[drivera84]

Nope, I don't think losing track of the miles will hurt your resale value on this at all. A good electronic speedo will run you $100+, I just use a bicycle speedo:

http://www.aerostich.com/sigma-speedometer.html

Double check the threading if you have to go this route, but I believe it was a standard size M18 oil pan drain plug from the auto parts store I ground down to plug my leaky tach drive. (pull the unit off, push the drive shaft out, plug and reinstall. I had to grind the bolt shorter and take down the shoulder of the bolt to clear the cam chain bulge in the case. A little redneck, but if you do it cleanly it looks good. Maybe just special order a nicer looking bolt) .

good thing you mentioned this...my gauge cluster had no tach...so I dont know where the cable plugs into the engine...could you please elaborate on this.... If you have pics it would be awesome!

[drivera84]

It's a good thing that the deal for the '80 750 motor fell through because it wouldn't have fit in that frame without mods. They're completely different motors/bikes.
When hunting for parts, be aware that 77-79 750s will all have compatable parts, while any 750 after 79 will likely have very few direct swap parts.

If you're hunting for a larger motor, a GS1000E motor will swap with some minor modification to the frame mounts but no other motor will be a direct bolt in besides a first gen 750 motor.

Good luck with your project.

thanks for the input! I feel better about fixing the original engine that came with the bike anyway!

I dont know if I want a bigger engine...I think the 750 is plenty power!!!

maybe in the future Ill see if I get my hands on a full dressed 1100...someday...

[verde]

good thing you mentioned this...my gauge cluster had no tach...so I dont know where the cable plugs into the engine...could you please elaborate on this.... If you have pics it would be awesome!

No tach from the factory or missing the tach? If they made a lower trim model without a tach, then maybe you already have some sort of factory plug there.

As for pics, you're in luck. I just snapped a pick of the leaky one on my '79 I haven't addressed yet. That screw at 8 o'clock holds a little retainer in a grove in the drive housing. The o-ring on the housing was fine on my '78, but the seals for the tach drive shaft were shot. You have to pull the whole housing out and then you can push the drive shaft out and either replace seals or just plug it.


And you're extra in luck because the bolt on my '78 has the threads printed on it. Note, as you can only get a few threads deep, I had to very carefully grind down the length and clen up the leading thread with a trangle file. Install with your choice of o-ring, silicon, sealing washer, whatever. Don't over tighten since there are so few threads and it's aluminum.

[drivera84]

No tach from the factory or missing the tach? If they made a lower trim model without a tach, then maybe you already have some sort of factory plug there.

thanks man...this is just what I needed....the bike was crashed before it was put in storage....the tach was broken and the cable removed.

Now that I see the little hole I dont remember seeing it in my engine...maybe it has already been plugged...I will get back to you guys no this...

[drivera84]

Hi guys,

While I wait for the engine to unstick...Ill begin working in the head. When I took it off about 5 years ago all I did was take it off and put it in a box. It has very little if any surface rust. What should I check?

How can I tell if the valves are good?

thanks

[240punk]

Check spring length per manual and the valve guides for wear.
Check valve clearances as well.

[drivera84]

Check spring length per manual and the valve guides for wear.
Check valve clearances as well.

is this all on cliffs page?

this would be the first time I do this so I will need detailed info on how to do this....If someone has done this before and has pics it would be great.

thanks to all you guys for your help...if it werent for this forum I wouldnt be doing this for sure!

[TheCafeKid]

It may not be on Cliffs site itself but likely he has a link for a downloadable shop manual which will have all tolerances and specs in it.

Inspect for rust, surface rust can be ok as long as it's not pitted the metal on moving/wear surfaces. Cam lobes, bearings, journals, just about any moving part needs to be free of pitting.

I'd be concerned about rust in the crank bearings. These are roller bearing motors, and of course any pitting on a bearing surface is bad but, roller bearings will pit with even the slightest amount of rust. A tiny pit will quickly grow.

With you being unsure how the motor is internally, I'd suggest breaking the entire thing down. Ive cracked a motor open before that I thought was a goner looking at the jugs. But the rings sealed, no water made it into the bottom end or not enough to do damage, and since those parts are in constant contact with oil, they tend to become a bit impregnated with it and makes them somewhat less vurlnerable.
I have a few spare motors laying about that are no good except for parts. If you need valves or such, let me know.

[drivera84]

That's as good an idea as any. WD40 isn't going to be a huge help, but maybe combined with diesel it'll be ok.

Remove the timing cover which is on the right side case cover. That should give you access to the end of the crankshaft which is where you should attempt to turn it from.

At least that's how it is for my 450 but I'm pretty sure the bigger ones are the same...

Hi guys, i took the left side cover tonight...it was pretty clean inside. This is the cover where the stator is located. I noticed a bolt right in the center and figured this would turn the crankshaft....i tried moving it and it felt like i was loosening the bolt. Am i turning the right bolt?

My bad....just noticed I took off the wrong cover....

[drivera84]

Hi guys,

I took the other cover off...there was a "double bolt?" i turned it and the crankshaft moved just a bit...i tried to rotate it the other way and the bolt began unskrewing.

Im sorry to sound like a complete newbie but I am...


What am i doing wrong?

[TheCafeKid]

Turning it the wrong way?
Use the 19mm ignition side bolt. On the end of the crank, on the right side of the engine if you were sitting on it. Small round cover. Remove it. Don't force anything if it really feels like it doesn't want to go.

Pulling a spark plug or four out will help too, as you won't be turning the engine against the compression that way. Motor spins clockwise (forward) from that side.