How far down the rabbit hole will I go... `78 GS750

[Tech73]

I am having some trouble putting the base cylinder on. I can't squeeze the rings together enough by hand to slide the cylinders down. I may have to go to crappy tire and see what they got that I can use. I need to find an oil filter anyways. Any suggestions would be real welcome.

I know some people that used hose clamps on the pistons to get the cylinders on. They were very very carefull when doing it and didn't hurt anything but I'm not sure I'd do it.

[Nessism]

I strongly advise you to remove the valves and replace the valve stem seals. Check Basscliff's website for a valve removal tutorial using a cheap C-clamp and piece of PVC pipe.

[bottobot]

I strongly advise you to remove the valves and replace the valve stem seals. Check Basscliff's website for a valve removal tutorial using a cheap C-clamp and piece of PVC pipe.

I got the base cylinder on, which was super difficult but luckily a friend randomly stopped by and we were able to work in unison to sweet talk those pistons into the cylinder. So now I am definitively gonna look at that tutorial.

[bottobot]

Use a popcycle stick or a piece of plastic.

Eric

I ended up using some plastic razor blades. Worked really well in conjuction with some gasket cleaner to get the rest of the gasket off. Then I was able to use them to get the rings on. The guy at Lordco was super helpful.

[bottobot]

You may want to check the diameter of those pistons and maybe the lift on the cams. Those look like Yoshimura pistons. Do they say POP Y on the side next to the wrist pin bore. The pistons look to have more dome than stock. If you have a stock head gasket it may not fit the bore. The cams look like they have some serious lift also. You just may have yourself a hotrod.

I didn't see this post. It could very well be that I have a hotrod. The pistons do say POPY on the side. Wierdly enough I did compare the gaskets to make sure they were the same thickness, and they are. Whats interesting is that the carbs have been re-jetted and there is an Dyna RPM Limiter on there. This bike has definitely been "raced out" a bit. After I clear out my build queue, you can see it in my forum sig, I am going to re-aproach this bike and re-do it properly. There is just so much wrong with it cosmetically that I don't have time for right now. I've more or less made the decision to put it back together and do a few more maintanence issues, like brake fluid flush and fork oil, and oil filter and strainer. Then call it a day and move on to the next. I need a couple more running bikes in my stable before I can spend the time on this one that it really deserves.

Here is another project that is active right now where a guy and his dad are restoring the same bike as me and doing a really killer job. Its making me super jealous and I want to do a lot of what they are doing to this bike too. Its hard to reconcile that I just don't have the time/money and tools to make it happen. Maybe in a few months. For now I will soldier on a get this bike running.

Your words of wisdom and encouragement have been very helpful to me everyone! I'm just an inexperienced backyarder trying to take it to the next level and it feels overwhelming sometimes.

[TeamDar]

Not gasket thickness, but bore diameter. If you put a stock GS750 head gasket with a 65mm bore on those 69mm cylinder you will have problems.

[BigD_83]

IF you need to get any machining done, I can recommend the guys at Alec's Automotive. Good shop, decent rates.

[bottobot]

Not gasket thickness, but bore diameter. If you put a stock GS750 head gasket with a 65mm bore on those 69mm cylinder you will have problems.

Ah ok.. I realize what you mean now. I just checked the old gasket and its a 65mm so I think I'm safe. Thanks for the good tip though. Always better to be safe than sorry.

[bottobot]

IF you need to get any machining done, I can recommend the guys at Alec's Automotive. Good shop, decent rates.

I've heard good things about those guys. Paul at Motomethod recommended them to me. When I do my next teardown and resto/mod of this bike I am going to get the to do a few things for me.

[bottobot]

Put it all back together today and it won't start. ****....

I'll pull the carbs off tomorrow and double check all the settings.

[bottobot]

So I've checked a bunch of different settings and tried a variety of configurations. No luck. The bike turns over but doesn't fire except when it makes a hella loud backfire. Had to check my ears once to see if they were bleeding. A backfire in an enclosed space is no party.

I'm pretty stuck here. I've check and re-checked the tutorials and pretty much ruled out everything I can. There is spark, I am pretty darn certain there is compression but I will double check it later, and there is definitely fuel and air but I have no idea if I have the right settings.

If anyone wants to chime in their 2 cents I am happy to hear it. Its a 4-1 exhaust with #127 main and 17 pilot with pods.

Before you give me grief about the set up please be kind, the PO did this and if I could put it back to stock I would in a heartbeat.

[BigD_83]

So I've checked a bunch of different settings and tried a variety of configurations. No luck. The bike turns over but doesn't fire except when it makes a hella loud backfire. Had to check my ears once to see if they were bleeding. A backfire in an enclosed space is no party.

I'm pretty stuck here. I've check and re-checked the tutorials and pretty much ruled out everything I can. There is spark, I am pretty darn certain there is compression but I will double check it later, and there is definitely fuel and air but I have no idea if I have the right settings.

If anyone wants to chime in their 2 cents I am happy to hear it. Its a 4-1 exhaust with #127 main and 17 pilot with pods.

Before you give me grief about the set up please be kind, the PO did this and if I could put it back to stock I would in a heartbeat.

Those numbers for your main and pilot seem about right based on what I've gleaned from other people's experiences. Maybe MisterCinders would be able to provide more insight. He's done extensive work on his '78 750 with 4 into 1 and pods.

What are the valve clearances at the moment?

[bottobot]

That's next up. After dialing the pilot air and fuel screws way out I'm getting really close. It actually fired up for a brief second. I am off to Lordco to get a battery as the battery I inherited is pretty weak it barely starts the bike even while connected to a charger

[BigD_83]

That's next up. After dialing the pilot air and fuel screws way out I'm getting really close. It actually fired up for a brief second. I am off to Lordco to get a battery as the battery I inherited is pretty weak it barely starts the bike even while connected to a charger

Before you hit Lordco, call Modern. Murray has/had motorcycle batteries at a pretty decent price.

[bottobot]

Before you hit Lordco, call Modern. Murray has/had motorcycle batteries at a pretty decent price.

I just tell Lordco I'm with the City and I get a pretty good price.