[keeena]

I picked up an old GS750 and its having a tough time turning over. I was told that the floats are stuck open and causing motor to flood. I'm going to be cleaning & rebuilding the carbs shortly.

However, my Q is regarding the starting. The starter motor barely turns the engine over. However, after I began pulling plugs the motor would turn over normally. I'm guessing one of two things: (A) cylinders getting flooded and causing motor to near lock-up (aka hydrolock), (B) exhaust valves very tight and not allowing pressure to evac. This sound right or no? Should I look at anything else? Electrics appear OK, lights are strong. I will be trying another known-good battery just in case. I get good spark. #1 plug seriously fouled...rest seem OK. I didn't notice any gas pump out, but there is existing seepage around #1 plug. Low miles - 14k.

[Degsy]

Plug 1 fouled. Bike sits on sidestand for years, #1 carb/float gets gummy (it's where the fuel flows to as it is the lowest) and sticks, floods #1 cylinder and fouls plug.

[keeena]

That makes sense. The orig. owner supposively just let this thing sit in his basement...didn't ride much.

Would the fuel cause much resistance to turning over? If there was lots of fuel in there I would've expected to see it pump out. Or is there a tappet clearance job in my future?

[SSearchVT]

If it was all flooded out gas would be misting out of the plug holes when you turn it over. More likely it a loose ground or flatish battery. With the plugs in the starter has to work harder - raising the current it needs. You can use a car battery of jumper box to jump start it and see if it's the battery.

At this point if the motor turns over easily by hand with the plugs out, and doesn't bind up - valve clearance is fairly low on the list. Find out if it runs first.

Drain everything you can out of the tank, and clean it the best you can (it's probably pretty rusty). Clean out the carbs (buy a rebuild kit with new jets and gaskets), put them back on, fresh plugs in all the cylinders. I like to put a few drops of gas in one or two of the cylinders for the first start up (lets the bike fire right off and fill the carbs). Good luck...

[TLRMan]

Ahhh just bring it to me...I'll fix it....

[Ryno]

Originally Posted by keeena

I picked up an old GS750 and its having a tough time turning over. I was told that the floats are stuck open and causing motor to flood. I'm going to be cleaning & rebuilding the carbs shortly.

However, my Q is regarding the starting. The starter motor barely turns the engine over. However, after I began pulling plugs the motor would turn over normally. I'm guessing one of two things: (A) cylinders getting flooded and causing motor to near lock-up (aka hydrolock), (B) exhaust valves very tight and not allowing pressure to evac. This sound right or no? Should I look at anything else? Electrics appear OK, lights are strong. I will be trying another known-good battery just in case. I get good spark. #1 plug seriously fouled...rest seem OK. I didn't notice any gas pump out, but there is existing seepage around #1 plug. Low miles - 14k.

if the valves were tight it would turn over very easily as it would basically have no compression.