Worth restoring?

[garp]

I bought a non-running 1979 Suzuki GS750L. It had been sitting for what looked like a few years at least, although the seller told me it was running last summer (yeah right). The oil had been drained, so I filled it with clean oil. The battery was dead, so I charged it. I put in the charged battery but the starter wouldn't work, just the solenoid clicked. The headlight was also dim and the horn was weak and eventually stopped working, which led me to believe the battery wasn't charged enough. So it is now charging some more. While it was charging I decided to check the compression by pressing my thumb on the spark plug hole and cranked the engine with the kickstart. To my horror there was no pressure. I'm not an expert so I don't know if I'm falsely testing the compression.
Now, is this bike worth working on any further? What's the worst and best case scenarios.
I'd just like to know if I'm wasting my time with this.

[Clint]

I'd guess the battery is junk. Try jumping it off a non-running car. However, if you were able to crank the bike fairly quickly with the kickstarter and felt no compression, you're right... it's toast.

Welcome. Do you ride anything else?

[AZRyder]

Originally Posted by garp

I bought a non-running 1979 Suzuki GS750L. It had been sitting for what looked like a few years at least, although the seller told me it was running last summer (yeah right). The oil had been drained, so I filled it with clean oil. The battery was dead, so I charged it. I put in the charged battery but the starter wouldn't work, just the solenoid clicked. The headlight was also dim and the horn was weak and eventually stopped working, which led me to believe the battery wasn't charged enough. So it is now charging some more. While it was charging I decided to check the compression by pressing my thumb on the spark plug hole and cranked the engine with the kickstart. To my horror there was no pressure. I'm not an expert so I don't know if I'm falsely testing the compression.
Now, is this bike worth working on any further? What's the worst and best case scenarios.
I'd just like to know if I'm wasting my time with this.

I think it all depends on how far you want to go to restore it. If there's no compression, changing the rings may be all it needs. Also, depending on what cylinder you were checking it on, a compression check via a kickstarter may not be accurate. If it's been sitting that long without oil, you may want to get a little marvel mystery oil and pour just a teaspoonfull or so in each cylinder via the spark plug hole. If there's no oil in the cylinders cranking it may damage it further.

Those older engines are pretty simple to replace the rings etc on. (I rebuilt my gpz 750 engine and while it was tedious, wasn't too difficult after reading up on it).

Of course you could always look for an engine on Ebay if the rest of the bike is in good shape. I've bought numerous heads etc. for my old gpz cheap.

[Apertureguy]

I hope you didn't pay too much. Although...that sounds like a fun challenge, it's not something I'd have the time for...maybe after I retire.

[DrBob]

I looked it up, and in in good, running condition the bike is worth $850. Subtract what you paid for it, and if will cost more than what is left then you are better off parting it out.

[garp]

I'm looking around the house for the jumper cables I swear I saw a while back in a box somewhere, which means I'll have to pick up some new ones tomorrow and try starting it that way. I haven't tried putting any oil down the cylinders. I'll try that next.
Does anyone know of a good material to make your own gaskets for cylinder heads and carbs? Ordering gasket sets is expensive.

[AZRyder]

Originally Posted by garp

I'm looking around the house for the jumper cables I swear I saw a while back in a box somewhere, which means I'll have to pick up some new ones tomorrow and try starting it that way. I haven't tried putting any oil down the cylinders. I'll try that next.
Does anyone know of a good material to make your own gaskets for cylinder heads and carbs? Ordering gasket sets is expensive.

You definitely don't want to make your own head gaskets. Definitely something that has to be pre made. Cometic makes the best after market gaskets. They're a little pricey but well worth it. I'm trying to remember where I got em for my GPZ. I'd keep an eye on Ebay, usually you can get good deals there.

[DrBob]

I agree- you need store-bought head gaskets, which have to be the correct thickness after they are torqued, and usually ave metal or other material embedded in certain areas for strength. Other gaskets can be cut yourself, using inexpensive rolls of gasket material from the local auto parts store. There are several different types (paper, cork, high-tmep, etc), and each roll will have suggested applications for that type of material.

[garp]

Thanks for the gasket advice.
So I picked up some jumper cables with the hopes of starting the bike, but it resulted in slight disaster. I followed the instructions to the tee. I used my car battery for the jump. Hooked up the positives in order then the negative and grounded it to the bike frame. No lights came on (which they did previously with dying battery) then the jumper cables started smoking and the rubber melted off the cables in a matter of seconds. I promptly disconnected them then had a stiff drink while contemplating my failure. This is driving me nuts.

[AZRyder]

Could be a shorted battery. I would try getting a new battery for it. Also check your fuses. I hope you didn't short anything out in the bikes electrical system.

[mike-s]

another thing to think about, it may just need top end cleaner put in the motor, a mate bought a zxr250 which had started to show really bad compression. He put in subaru's top end cleaner as per instructions and left it for a few days, came back, changed the oil, and it showed signs of improvement, went from showing compression of 90/100/70/70 per cyl up to 150psi for every cyl. also remember there'd be bugger all seal at the moment due to the engine being stationary for so long. id spray a light bit of lube down the spark plug hole first as well as maybe pouring some oil in the top end for lubrication purposes.

but yeah, check your battery, also perhaps go over the bike with a multimeter to make sure things aren't grounding where they ought not to?