Heat wave

[Shaka]

Very true!  I know what a stickler you are about your fuel efficiency though!  Just thought I'd throw that out there.

[jprestonian]

True enough. But if I blow the damned thang up, its mileage ain't gonna get any better, for sure.  ;)
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[wordslinger]

The only possible draw back w/out a t stat. is the temp could keep climbing on very hot days. It adds just enough blockage of the coolant to keep it in the radiator long enough to remove the heat. MOST ALL engines will have little/no trouble w/ no t stat, but the marginally designed ones will. Better to remove it for a test run, and get one when you can. I also believe there is a nylon adapter that runs your coolant pump. Might want to make sure the pump is working too.

I head awhile back that an engine can run too cool.  If it runs cooler than the optimum temp it runs less efficiently.  This is why truckers have the radiator flaps for the winter time.  It will still run, you just may have a slight drop in fuel efficiency.



..lesson learned...thermostat 101...   

[axy]

True enough. But if I blow the damned thang up, its mileage ain't gonna get any better, for sure. 
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I did not read the thread carefully.

Does the fan turn on when the engine heat gauge goes into red zone?

Lucky you, I do not have that gauge on my P250S...

[ispud]

no temp gauge was my first gripe.

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[jprestonian]

Going on the logic that it would be better to have a faulty thermosensor than a thermostat stuck nearly-closed (which is what I now suspect, after getting your valuable feedback), I've got a new thermostat on order. Can't believe what the markup on these puppies is... wow.

I should have taken the old one out, today, but it's managing to stay open enough to keep it from staying pegged all the time. Still no coolant in the weep hole, and the scooter's running fine. I did take a break on my trip today to let it get stone-cold again before doing the other half of my short (10 mile) trip. Plus, the part should be here no later than Tuesday. I'll just try to keep trips very brief, and/or take breaks in the middle of rides like today's.
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[zombie]

Have you checked your coolant level? I have seen where steam being hotter than the coolant itself will bounce the needle as it passes the sensor. Just another thought, as I see you have it under control.

[jprestonian]

Well, yes, in a manner of speaking. We replaced the thermostat last Thursday or Friday, and there was an immediate improvement. However, the larger improvement didn't come until Saturday, when I burped a half-pint or more of air out of the cooling system. I think there's still some in there, but not enough to cause the severe overheating I was getting.

Air in a system like this can cause cavitation, which is very stressful on things like impellers, hence seals and water pumps. So over the course of the next few days, I'll be constantly burping it, and adding coolant.

Damn shame it takes 10 screws to get the front cowl off.
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[zombie]

I was thinking about you 2 nites ago, and your overheat. Good to see you got it. As for the cowl... Run NAKED IN THE STREETS. I would pay to see the blog...

[TechGuy]

I was glad i had temp gauge this weekend.  My exhaust pipe blew but I was able to fashion a fixed with a muffler wrap and soda can (that failed 300 miles later, replaced with a slightly better patch made of stainless steel strap and hose clamps.)

I kept an eye on the temp gauge the whole weekend.  I was able to ride over 700 loud miles by watching my temp gauge.

[axy]

Well, yes, in a manner of speaking. We replaced the thermostat last Thursday or Friday, and there was an immediate improvement. However, the larger improvement didn't come until Saturday, when I burped a half-pint or more of air out of the cooling system. I think there's still some in there, but not enough to cause the severe overheating I was getting.

Air in a system like this can cause cavitation, which is very stressful on things like impellers, hence seals and water pumps. So over the course of the next few days, I'll be constantly burping it, and adding coolant.

Damn shame it takes 10 screws to get the front cowl off.
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Would you care to explain a bit how is the coolant replaced in P250?
Thanks.

[jprestonian]

On the People 250 (not S 250, although the concepts are the same), I remove the ten screws that hold the front cowl to the other body panels, unplug the turn indicators, and remove the cowl and set it aside.

I then open the radiator cap, and add coolant, if there is not coolant all the way to the top of the cap. Then, I start the engine. As the engine warms, and the thermostat opens, coolant circulates through the entire system, and air bubbles will come up into the radiator, and eventually out the filler cap. This causes the fluid level to drop, so I again add coolant.

One can only do this so long before the whole system gets so hot as to splash out coolant, and not just air. At that point, I shut off the engine, and let it cool, and repeat the process.

I imagine if you wanted to drain all the coolant, disconnecting the big hose at the bottom right that connects to the impeller, and very briefly running the engine (w/radiator cap open) would quickly drain most of it.
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[axy]

On the People 250 (not S 250, although the concepts are the same), I remove the ten screws that hold the front cowl to the other body panels, unplug the turn indicators, and remove the cowl and set it aside.

I then open the radiator cap, and add coolant, if there is not coolant all the way to the top of the cap. Then, I start the engine. As the engine warms, and the thermostat opens, coolant circulates through the entire system, and air bubbles will come up into the radiator, and eventually out the filler cap. This causes the fluid level to drop, so I again add coolant.

One can only do this so long before the whole system gets so hot as to splash out coolant, and not just air. At that point, I shut off the engine, and let it cool, and repeat the process.

I imagine if you wanted to drain all the coolant, disconnecting the big hose at the bottom right that connects to the impeller, and very briefly running the engine (w/radiator cap open) would quickly drain most of it.
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Thanks.
I was wondering, is there some other way to drain the fluid out than disconnecting the hose? It sounds kind of "crude".
The cars usually have some kind of screw, screws or several drain plugs.