Can't get my '82 GS750T started...

[froldt]

I bought her a couple of weeks ago, rode for about a week, and now she won't start. For a couple of evenings, she wouldn't start, and I thought that she was just cold natured and needed a new set of plugs/carb rebuild. Then she wouldn't start at all. The next morning, she fired up first try, no problem, barely any choke needed. Rode to my girlfriends house, and she's been there ever since.

Press the start button, and she turns over, but that's it. I checked, and each of the spark plugs fire. Replaced them with new ones (the old ones looked pretty good, I'll brush them up, regap and save them for spares).
Gas coming out of the tank, so it's at least getting to the carbs.

One thing that I realized this evening, is that I was using the petcock wrong. I mis-read it and was using ON as Off, and PRI as On. I'm sure that didn't help anything. Probably explains why she was a bit erratic sometimes, as well as why I got some horrible gas mileage. Yes, I know I goofed, but I definately learned from that one, and hopefully no other newbies will do the same thing!

I've taken the tank, battery, airbox, and some other goodies off. I'd already ordered a chain/sprocket set, carb kits, and petcock kit. Soon as I can find a gasket, I'll check the valve clearances, while I've got it apart.

Anyway, does anyone have any suggestions? I've got a sort of journal going, here, and I've received many helpful suggestions already. I did just think of the fuel valve mis-hap tonight, and thought that I should post here to get further advice.

[Nessism]

The PRI (prime) position allows gas to flow at all times, even when the engine is shut off. The ON position only allows gas to flow when the engine is running since vacuum from the engine is required to pull the diaphram open. In either case, it's your float needles that control how much gas is allowed into the float bowls. Leaving the petcock in the PRI position in effect forces your needles to control this flow even when the engine is turned off - which should be no big deal assuming they are functioning properly.

Just a guess on your problem but most likely you have gunked up carbs causing the problem. Clean them and then see where that leaves you. Also, check the valve clearances, ect. before expecting too much from the bike. After all the basic maintainance is done and if it still doesn't run right, that's when you need to start thinking about what to do next.

[Magoo]

I had a similar problem. I would check your battery, because it ended up when I had the problem the battery levels were really low. I added more liquid and charged it up and haven't had too bad of a problem since.
perhaps.

Christopher Magoo

[omaharj]

Just a thought. Since you're messing with the petcock,do you have more than the reserve amount left in the tank? (I always hope it's the simplist thing):-D

[tconroy]

Check your crankcase for gas.if you left it on prime chances are you have filled up your crankcase.your not trying to start it without the airbox are you?Try a little starting fluid in the first plug and see if it will fire.if so you probably have a carb issue.

[QuaiChangKane]

Have you tried starting it again in the prime position?

If it works, sounds like a bad petcock.


If it doesn't help, try a shot of ether in your airbox. If it fires on ether, then it's a fuel problem.

Could be other things, too - when it was running, was it running smoothly, idling smoothly, accelerating/decelerating smoothly? Was it getting hot or popping when you rolled off the throttle?

From your smooth cold start with no choke, it sounds like you might be running rich - what color are your plugs?



Personally, I'd try the simple things first. Check your petcock, check your fuel lines, check your airbox, check your battery, check your plugs, check your plug wires, check your coils, check your points, check your valves. Then pull the carbs - check the boots and clean the carbs. One step at a time, so you can tell which step actually solved your problem.


Start with the basic maintenance items, and work your way up. Just be prepared to answer a million detailed questions on here to get you troubleshooted (shot?).




But before anything else, do smell your oil for signs of gas, and change your oil & filter if it's fouled.


Good luck,


-Q!