87 VF500F Overheating

No slime whatsoever. I'm not leaning towards it being a head gasket. I've been an ASE Master Tech (automotive) for alot of years and recognize head gasket failures, this doesn't appear to be one. No excess bubbles in radiator, no 'smell' from the exhaust, no smoke, no slime, none of the telltale signs you'd see normally.

I'm starting to think it's the sender, but won'thave the chance to swap it out until later today. I'll post an update when I know more...

Thanks for all the suggestions!

Wayne

 

This might be my final UPDATE...well with regards to the overheating issue, maybe.

I used a Snap-On digital laser temp gun to measure the temp at the top of the thermostat housing with the engine COLD, had been sitting approximately 6 hours since last ride.

COLD temp was 100F.

Rode the damned thing till the gauge was halfway....temp at the top of the thermostat housing was 158 degrees F.

Rode some more til the needle on the gauge was at HOT...temp at the top of the thermostat housing was 181F.

Temp at lower left radiator tank was 172F. Temp at water pump housing was 178F. Temps at the two hoses that come out of the bottom of the thermostat housing were 155F.

So, it seems to me that the sending unit is sending a faulty signal to the gauge. All of this is while running the engine WITHOUT a thermostat.

I'm hoping that I've narrowed it down finally. The possibility of a blown head gasket would have probably had me selling the damned thing. I've got enough projects around as it is, don't need one more. And the wife is on my ass to learn to ride, this is HER bike as it is!

Wayne

 

Cold temp was 100 degrees F.?? That sounds like Texas !

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You can measure resistance of the sending unit (to ground) for reference.

FYI: fan's supposed to kick in at 100 C.

 

Yep, definately Texas! Over 65 days this year of 100F PLUS.....But also keep in mind that I'd ridden the bike about 4-6 hours earlier too.

I still haven't changed out the sending unit, but plan to do so either today or tomorrow. raining all day today so I might do it since I'm rained out at work today.

Well, gotta run. Gotta catch crickets to feed my bearded dragon!

W