My bike is HOT

[Killer2600]

And I'm not talking about looks. The last few times I've taken the bike on the highway and hit 70 MPH after a bit (15 mins or so) the oil temp gauge will start reading a pretty hot temp...On a long 45 min run at 70-75 (and maybe more) MPH I've seen the gauge read a needle width away from 320 degrees and I know it's not good.

So how do I fix this, no it's not just the temp gauge reading wrong the engine is genuinely hot (I can feel the heat emanating from it while riding or after shutdown). If it was water cooled I'd fix the cooling system but this is air cooled and I'm sure I was getting air. Also to add the first time I noticed the temp getting hot it was a hot day (90's) and I wasn't catching air (going slow) but revving the rpms up every moment or so. That time I attribute to the lack of air flow but 70 mph on low 80's or a mid 90's day I would think should be enough to keep it cooler than just shy of 320 degrees.

NEED HELP, short of making an aftermarket watercooling system I don't know where to start.

[Dave8338]

A few others here have posted such temps...the only thing that I can suggest is to ensure that you're not running lean. Do a plug read, they should look a light tan in color. If they are looking gray or white, you are running too lean, (is your bike stock)? Are the header pipes showing any signs of blueing?

[Killer2600]

A few others here have posted such temps...the only thing that I can suggest is to ensure that you're not running lean. Do a plug read, they should look a light tan in color. If they are looking gray or white, you are running too lean, (is your bike stock)? Are the header pipes showing any signs of blueing?

The bike is stock setup, the pipes aren't blueing any that I can tell cept for the 90 degree bend right after the cylinder head exhaust exit is shiney and maybe showing reflections with a blueish tint (I'd have take a really good look to see if its actually blueing the pipe). As for lean, when I bought the bike and changed the plugs they were obviously rich and when I changed them the next time they were rich again. So I'm guessing I'm not lean but then again I've never really done so many long highway runs on this bike so I will check the plugs again.

[txironhead]

Some people have posted here that running synthetic oil drops the temps. I also know that if your timing is off it'll overheat the bike.

[chef1366]

Make sure the airbox, airbox boots, intake boots and o-ring behind intake boots are all sealed up.
Get a oil pressure quage from renobruce and check the oil pump.

[Nessism]

Some people have posted here that running synthetic oil drops the temps. I also know that if your timing is off it'll overheat the bike.

Synthetic oil will not make your bike run cooler but it will protect the engine better in those high temp conditions since it has better high temperature stability.

As the others have said, make sure the engine is not running lean. Other than that the best way to bring down temps is to install an oil cooler. The second generation GS series bikes have oil coolers from stock so Suzuki recognized the issue and took positive action.

[Killer2600]

I've pulled the plugs and this is what they look like






I'm guessing that all except for #3 are running lean, guess I'll recheck the intake boots (sorry no o-ring on my bike) for proper seal and leaks.

For anyone that wants to tell me my petcock needs replacement cuse it's leaking fuel out the vacuum line--The plugs are numbered correctly and the vacuum connection is on the #2 carb not #3.

[Nessism]

Your plugs are a little too old to get a good "read" off of. If anything they look like the engine is running rich, not lean. Does it burn oil and if so, how much?

[Killer2600]

Your plugs are a little too old to get a good "read" off of. If anything they look like the engine is running rich, not lean. Does it burn oil and if so, how much?

Yea they've had a good many miles on them but I'm not burning any noticeable amount of oil and never any blue smoke. If they are indeed rich I don't know why #2 plug insulator would be so white. But then again I have no blueing on the pipes what so ever so this is driving me mad. I mean is 320 degrees a normal oil temp for running 70-80 MPH in open air because if I run about 45 MPH around town the oil temp gauge is half way between either extreme and sometimes a little hotter than half way. Once I hit the highway and run 70-80 MPH the temp works it's way up there all the way to just shy of the 320 mark (it'd probably go higher if I rode it longer).

[twistedwankel]

Your plugs are a little too old to get a good "read" off of. If anything they look like the engine is running rich, not lean. Does it burn oil and if so, how much?

Agreed you are running rich.

At speed you shouldn't be running hot with all that air over the engine? You are certainly not at redline yet.

Got gas in your oil? Changed it lately? Running flat out for hours? The speed limit here is 70 and most people live with 75. Your problem isn't your plugs it's your bean.

Which set of plugs are you referring to? They all look like a "rich" problem.

Normal oil is good for 450F. So not an issue yet. Buy more insurance tho' for the family.

[Killer2600]

Agreed you are running rich.

At speed you shouldn't be running hot with all that air over the engine? You are certainly not at redline yet.

Got gas in your oil? Changed it lately? Running flat out for hours? The speed limit here is 70 and most people live with 75. Your problem isn't your plugs it's your bean.

Which set of plugs are you referring to? They all look like a "rich" problem.

Normal oil is good for 450F. So not an issue yet. Buy more insurance tho' for the family.

Insurance? where do you get that?....LOL j/k

The speed limit is 70 here also but everyone does the usual 5 over so the typical speed is 75 and when you add in a good few wanna add 5 to that you end up at 80 so on the highway your speed is anywhere from 70-80 to ride along with the cars and for bikes it's safer to go a little faster than cars rather than ride alongside them so sometimes you'd end up at 85. Not that I'm a speed addict seeking excuses to speed. Actually I really don't ride "fast" but I do have to keep pace with traffic and defend myself from idiots.

Back to the original topic, I have changed the oil this past april after noticing gas in it (one of the floats leaked gas after I took it out of storage and primed it). I believe the leak was sorta self-correcting after the float and needle got some fuel flow and movement, the oil level hasn't risen like it did before since the oil change and at last smell (month ago or so) no gas detected.

Ok it's settled I'm running rich, now if my wallet was running rich I'd be extremely happy.

Oh yea the three pics are all the same plugs just taken at different angle/lighting

[Rock]

Are you reading those plugs by doing a chop test? You will not get a true reading if you are just going for a ride and then pulling the plugs after and looking at them.

[Killer2600]

Are you reading those plugs by doing a chop test? You will not get a true reading if you are just going for a ride and then pulling the plugs after and looking at them.

Well the plugs are old with many miles on them but regardless you can determine running condition by checking them--even with many miles...If you ride a rich bike for hundreds of miles you'll see it on the plug verse if you ran lean for hundreds of miles and same with oil foul, lead foul, pre-ignition, and all the rest. When I got the bike my cousin a bike mechanic did a proper plug read after he and I put new oil, oil and air filter, plugs, carb cleaning and battery. It was rich then but since then I've taken the carbs off a few times and have done other work to the bike so I wasn't sure if it drifted to the lean side from air leak or something. My main concerns are running lean and overheating, if I'm not doing either or messing up the bike some way I don't mind seeing almost 320 on the oil temp gauge. It's just been my experience that manufacturers of mechanical things (autos and bikes for this post's purpose) don't make gauges where "normal" reaches the highest mark (320 degrees for my oil temp gauge). If I keep off the highway and max out at 45-50 mph the oil temp gauge will never go above half until I get stuck in stop and go traffic.

That's all my concern is, I just don't wanna f up the bike. I bought it cheap but I've put alot of money, heart, and soul into it so I'm very protective of it.

[Rock]

Killer2600, all I can tell you is if you don't use the chop test you won't get a accurate read in my and many others experience. The plugs can change color VERY quickly.

[Killer2600]

Killer2600, all I can tell you is if you don't use the chop test you won't get a accurate read in my and many others experience. The plugs can change color VERY quickly.

True oh so true but you only need the accuracy when dialing in the fuel mixture. I'm just doing a running condition assessment so I'm not gonna bother chopping new plugs. Air-cooled bikes suck, can't believe going slower = cooler engine.