Engine over heating

[Eidollan]

I have a 1983 gs750es, I don't know why but recently my bike keeps on overheating, and by over heating I mean over heating it's smoking, when I shut off the engine and start it again I can hear the starter motor is having a hard time cranking, I also notice at idle the engine is like struggling not to die. This would normaly happens when riding for 20-30mins, specially when it's a stop and go situation. Engine has new gaskets, cleaned the oil paths, and check if oil is flowing and it does. I also notice when it's hot the clutch is dragging.

I've also check the spark plugs and I'm actually running a bit rich, so I'm sure its not because of lean mixture.

Need help figuring out why it's overheating at a normal use.

[Rob S.]

I have a 1983 gs750es, I don't know why but recently my bike keeps on overheating, and by over heating I mean over heating it's smoking, when I shut off the engine and start it again I can hear the starter motor is having a hard time cranking, I also notice at idle the engine is like struggling not to die. This would normaly happens when riding for 20-30mins, specially when it's a stop and go situation.

Need help figuring out why it's overheating at a normal use.

This is not normal. The first summer after I picked up my 11E 9 years ago, the oil temp gauge was registering way too high, especially during high speed runs in the mountains. There were no other symptoms so I installed an oil cooler. Now it runs very cold, hardly ever registers over 200 degrees.

While a cooler may help your situation, I think you need to look deeper at what's causing this situation. Does your bike have an oil temp gauge?

[Eidollan]

Sadly my gauge is broken and I had to replace it, so no I don't have a temp guage.

I just notice something, I just check the oil level it seems fine it's very close to he high level, just a tad bit under, but I did notice there's oil on top of the crank case, no sign of leakage from the block or valve cover, I'm guessing from the oil hose from the crank case to the block? It feels like oil is coming out from there, could that be related?

I'm also thinking if the oil cooler is all clogged up, could it cause that? I still have the stock oil cooler installed

[Grimly]

First thing to check is the ignition timing. The 83 will have electronic advance in the ignitor box, and there's a chance it's thrown a wobbly and advancing too far in normal running. Perhaps not enough to let you know by any pinging noises, but just a few degrees will raise the temperature.
You need a timing light.

[Cipher]

my god what are ambient temps in NJ today around freezing?
That being the case shut this thing down before you destroy it

From the coolers I have seen and the one in my bike Suzuki uses the pressure of the oil to open the valve that allows flow through the cooler. But if you engine is smoking then your oil is plenty thin.

You say its not intake enleanment fine and dandy. try fresh plugs and see how they read try at least one at least one.

Quick and dirty check as its the first stop for oil after the sump screen is the filter pop open the cover and inspect.
You say ther is oil possibly from the top oilers for the head. Well if you take on off and crank ( no Start ) oil should fire outta the hose like mad, Does it?

I suppose as youve driven many a mile the thing would have grenaded already if oil starvation was the cause.

[fbody_mike]

You should really get a infrared temp gun that way you can measure how hot and know what progress you make. After a good highway ride my air-cooled bikes are around 300 degree F at the cooling fins, that is hot, but not overheating.

A quick sanity check I use for oil flow is to check the oil level with the engine off, then start the engine and let idle, typically the level will fall to the very bottom of the site glass or even below it, this lets me know that the oil is being pushed around the engine, I then watch that it returns somewhat quickly (about 1 minute or less) after I shut off the engine.

I have had engines that were flooding due to bad floats that appeared to be overheating because of the smoking, smell, and yes starter drag from liquid in the cylinders. Give that oil a good sniff for gasoline.

[Eidollan]

First thing to check is the ignition timing. The 83 will have electronic advance in the ignitor box, and there's a chance it's thrown a wobbly and advancing too far in normal running. Perhaps not enough to let you know by any pinging noises, but just a few degrees will raise the temperature.
You need a timing light.

Thank for the advice I'll check the timing soon I'm just too tired and drunk today

[timebombprod]

Ever notice your fuel tank level to be lower than it was last time? You could have a faulty petcock that's slowly leaking fuel into the carbs, and eventually goes into the cylinder past the rings and in with the oil, I've had it happen before and that's the only reason it ever overheated.

You have a 750 it's not the biggest GS and it's only a size larger than mine you shouldn't need any cooling assistance other than the fins so there's definitely an underlying issue.

[Eidollan]

Sadly I'm stuck here in the Philippines because of covid, this is my bike here, I'm a bit suprised it's a bit cold for a tropical country now a days, currently I'm using 10w40 oil which is the recommended oil here and for the bike. I don't think oil starvation is the case, from the oil window its showing full and I just changed my oil just a few weeks ago I only ran the bike like less than 100 miles after that. I will try chnaging the spark plug see what color it gives

[Eidollan]

my god what are ambient temps in NJ today around freezing?
That being the case shut this thing down before you destroy it

From the coolers I have seen and the one in my bike Suzuki uses the pressure of the oil to open the valve that allows flow through the cooler. But if you engine is smoking then your oil is plenty thin.

You say its not intake enleanment fine and dandy. try fresh plugs and see how they read try at least one at least one.

Quick and dirty check as its the first stop for oil after the sump screen is the filter pop open the cover and inspect.
You say ther is oil possibly from the top oilers for the head. Well if you take on off and crank ( no Start ) oil should fire outta the hose like mad, Does it?

I suppose as youve driven many a mile the thing would have grenaded already if oil starvation was the cause.

Sadly I'm stuck here in the Philippines because of covid, this is my bike here, I'm a bit suprised it's a bit cold for a tropical country now a days, currently I'm using 10w40 oil which is the recommended oil here and for the bike. I don't think oil starvation is the case, from the oil window its showing full and I just changed my oil just a few weeks ago I only ran the bike like less than 100 miles after that. I will try chnaging the spark plug see what color it gives

[Eidollan]

You should really get a infrared temp gun that way you can measure how hot and know what progress you make. After a good highway ride my air-cooled bikes are around 300 degree F at the cooling fins, that is hot, but not overheating.

A quick sanity check I use for oil flow is to check the oil level with the engine off, then start the engine and let idle, typically the level will fall to the very bottom of the site glass or even below it, this lets me know that the oil is being pushed around the engine, I then watch that it returns somewhat quickly (about 1 minute or less) after I shut off the engine.

I have had engines that were flooding due to bad floats that appeared to be overheating because of the smoking, smell, and yes starter drag from liquid in the cylinders. Give that oil a good sniff for gasoline.

I did that, after my bike cooled Down I check my oil level and it was high started the bike and it when down normaly as expected, let it idle for about 5 mins or so shut her off and oil came back down too the sump with in a minute more or less.

I actually suspect the floats too, because in the past I remember 2 carbs was over flowing, I actually for got to put it back to the on position from res after gassing up, went back home notices the smell of gas in my garage and saw gas dripping and the color of the oil changed to red and kinda translucent, drained the oil and half of it is already gasoline. I might not have adjusted enough the floats and still it over flows. Thank for bringing it up.

[Eidollan]

I suspected that too so I took off the tank checked the petcock and no dripping, but I suspect I have a float issue in my carb.

[Eidollan]

So here's what I found seems like oil is flowing OK, timing seems to have jumped, checked the timing mark and instead of the line before F like the service manual shows, it's the F that is aligned to the timing mark, could that caused it? Also I suspect the flow bowl is over flowing and gas is getting in the oil sump and thinning the oil.

[Eidollan]

She is fixed not over heating anymore, had a float problem carb was over flowing and the oil cooler is clogged, found out when I just remove one hose from the oil cooler, the hose was gushing out oil but the oilcooler flow was very weak, replaced it ride my bike for 100 miles no issue. Thanks for the advice guys really helped