Top end oiling issue

[headsbikesmopars]

Larry D, sorry about your situation with your bike. My son has a 1981 GS750E 16 valve motor, when he picked up used , it had 27000 on it. It also had a ticking under the valve cover. It had the same oiling issue, oil starvation at the number 1 journals, int. and exh. Both cams were trashed and so was the head. It ran but wouldn't rev above 4000. I replaced the head (used) did some port work while it was down and did a radius valve job and back cut the stock valves. The flow numbers are 75 cfm @ .350 lift. These are in the GS1100 16 valve range. Not bad for a 750. Took .010 off the head, new valve seals. We went with stock GS1100 cams , they are a drop in deal, and a give a good hp pick up with the head work. They were free I had them on the shelf. We replaced all the rod and main bearings the rods and the crank were in excellent shape. Cylinders only had .001 taper in the bore. We honed the bores, installed new rings std. bore size. (OEM). Cleaned out all the oil galleys, flushed and cleaned the cases, new oil pump, new cam chain, and a complete gasket set. With all the new parts including the cost of the used head, we have around $600.00 in this engine, doing all the work ourselves. Suzuki rated this engine @ 79 hp. With the head work along with the cams and V&H 4 into 1, I would put this one in the low 90 hp range 90-92 maybe. I know it is one of the hardest pulling 750's I have ever ridden. Larry,...we had to rebuild the engine so we just looked at it as an opportunilty to make the changes he wanted to make while it was down. You might not choose to or need to go thru the whole rebuild thing. Anyway..good luck on your bike Larry.

Terry

[Larry D]

Cleaned it up some.

Pulled the carbs and removed the cam chain tensioner. Moved the camshaft out of the way and had a look. Here's what I found. Again it's the #1 intake and that camshaft end. Not good.....










In the last the last pic you can see the tiny port where oil is supossed to come out below the cam lobe. I took a small wire and did some probing. It feels like the hollow rod has a slot below that hole to let the oil pass. Didn't feel obstructed.....

Seems a new camshaft is in order. Do they need to be replaced in pairs ? Also, anything I can do about the scoring on the camshaft end journal ?

It appears my riding is done for awhile....

[almarconi]

Hey Larry, Sorry to hear about your bike. Maybe would be a good opportunity to replace the 750 with an 1100. Probably cheaper than rebuilding the engine you have.

[Larry D]

This would be a good opportunity to replace the 750 with an 1100. Probably cheaper than rebuilding the one you have.

Bwringer and I discussed that last night. Just want to get down to brass tacks and see what else....if anything.... I could do.

At this point I'm at the proverbial crossroads. I have revived this particular bike and would hate to abandon it. Swapping an 1100 engine in there is an option. The other is finding another '80-'82 750 engine or at least the top end, and replace that.

It doesn't appear to me to be a repair, replacement seems the only option to ride this bike again. Don't really want to part it out and get another bike but, I suposse, that's an option as well.

[TheCafeKid]

Bwringer and I discussed that last night. Just want to get down to brass tacks and see what else....if anything.... I could do.

At this point I'm at the proverbial crossroads. I have revived this particular bike and would hate to abandon it. Swapping an 1100 engine in there is an option. The other is finding another '80-'82 750 engine or at least the top end, and replace that.

It doesn't appear to me to be a repair, replacement seems the only option to ride this bike again. Don't really want to part it out and get another bike but, I suposse, that's an option as well.

Larry, If you want another motor to use for parts, or it might even be good to go itself (I have not checked it out) MRiddle has a 80-82 750 motor sitting in my garage that is a spare. He may be willing to get rid of it fairly cheap. I also have a motor, but its more or less suffered the same fate, so I couldnt in good consience sell it, but if you simply WANTED it, i would toss it to you for coming to get it...

[blowerbike]

i'd start looking hard right now at other engines...
you may find one for as little as a 100 bucks..
just ask the owner the right questions and pull the VC and oil pan and have a look.
walk away from what you have right now,
if you dont you'll always be wondering in the back of your mind when it will happen again.

[Larry D]

Larry, If you want another motor to use for parts, or it might even be good to go itself (I have not checked it out) MRiddle has a 80-82 750 motor sitting in my garage that is a spare. He may be willing to get rid of it fairly cheap. I also have a motor, but its more or less suffered the same fate, so I couldnt in good consience sell it, but if you simply WANTED it, i would toss it to you for coming to get it...

Thanks Josh. Not real sure what I want to do yet. But, I'll shoot MRiddle a PM. Brett mentioned that Rob at CRC2 has one too, which would be easier to get my hands on and transport.

I feel like I'm wandering around looking for something I lost......

[TheCafeKid]

Thanks Josh. Not real sure what I want to do yet. But, I'll shoot MRiddle a PM. Brett mentioned that Rob at CRC2 has one too, which would be easier to get my hands on and transport.

I feel like I'm wandering around looking for something I lost......

Sucks dude. I feel bad for ya. I dunno what Id do if i only had one ride. Well, untill i get these others running again, i do, but there are at least options if something got seriously blown up. Keep your head up bro. If you decide to get another bike, give me a shout this fall/winter. Im slowly coming to the realization that Im going to have to get rid of something at some point, or im not going to be able to store it all...Dunno what that will be yet, but we'll see...

[Larry D]

Sucks dude. I feel bad for ya. I dunno what Id do if i only had one ride. Well, untill i get these others running again, i do, but there are at least options if something got seriously blown up. Keep your head up bro. If you decide to get another bike, give me a shout this fall/winter. Im slowly coming to the realization that Im going to have to get rid of something at some point, or im not going to be able to store it all...Dunno what that will be yet, but we'll see...

Thanks for the support. Two bikes are always better than one !

The wife asked how much it was going to cost to fix. I told her I wasn't really sure yet.

She says. "If it ends up costing too much, just go buy another one."

I love that woman !!

[almarconi]

Since you have put a lot of time and money into the bike you have, I see no reason to get rid of it. The bike is after all in really good condition. After the shock has worn off, you could take the top end off and see the extent of the damage. At that point you could make a more informed decision.

The L models can be had relatively cheap so getting an entire parts bike or another engine should not be a problem. If it happened on my 750L (I stopped keeping track of how much I've spent on mine), I'd replace it with an 1100 and keep on riding it.