First Gen. Cooling: would a higher CFM Fan help?

[azxvz1284]

I'm in Phoenix & we have 114 degrees. Yes, the temp needle?sits on the green/red boarder most of the time. I ride with an Ice-pack vest. I ride an '84 Venture with the fan override on, alot. I think the stock radiator fan is rated at 650-750 cfm. Hoses, coolant mix, radiator, impeller, and thermostat are all good.

 

Question: would having a higher-rated (CFM) fan result in a lower coolant temp? If so, are there any suggestions?

 

Thanks!

 

[videoarizona]

Hmmm, I have an 89 and don't ride in 108! But do ride close to 100 degrees. My temps stay in the middle of the gauge. As far as I know, the fan hasn't come on yet...even when running up one of those hills on the way back from Payson a week ago.

 

I would make sure the connection for the temp gauge is clean...since you stated everything else is good. On right side, lower front..under chrome piece.

 

Regarding a higher CFM fan. Maybe. But the amp draw will be higher as well, since the motor is working harder to turn the fan blade.

 

Have you ever gone into the red zone? If not...and your temp is stable even in Phoenix traffic...your cooling is probably working well.

 

david

[djh3]

Well I cant say for sure on these machines, I can tell you my experience with cars. @ identical vehicles may show different ranges on a gauge. It can be the dash gauge or it could be the range the sensor reads and puts out.

I higher pull cfm fan may help and I think most of that is either the number of blades on the fan or the curvature of them to make it pull. Only way you are going to know completely what temp it is running at is put a numerical reading gauge on it. I guess you could use one of those shot it heat sensor guns. Is the coolant new? or how old is it? Is thermostat opening all the way or partially restricted?

[mralex714]

You might try a 60/40 water to coolant (water cools better) and some water wetter. I also changed the fan switch to a lower temp one, so the fan comes on just above half way on the gauge.

[Peder_y2k]

Your carburetors could also be out of adjustment (usually pilot screw setting). A rich or lean mix will cause higher engine temps and result in unburnd exhaust gasses entering the exhaust making the exhaust at the outlet too hot to hold the back of your hand 1 inch away. On my excellent running '88VR, I can hold my hand at the exhaust flow till I get bored with it all

-Pete, in Tacoma WA USA

[Flyinfool]

There is probably no fan that will fit that can get close to matching the ram air through the radiator at 55 MPH. Having the fan on at highway speed can actually restrict airflow through the radiator. On an airplane a spinning propeller is more drag than a stopped propeller.

[cimmer]

When I flushed my cooling system last year I installed a little bit of Purple Ice and that helped lower my cooling temps I was seeing on the gauge. Might be worth a try.

 

Rick F.

[jdross440]

A few years ago when we were having temps in the 105 range I changed my thermostat to a NAPA THM 156 auto thermostat (abut $8 now). That seemed to help at speed. But at slow or stopped it would still run close to the red line. I replaced the fan switch and that let the fan come on quicker and helped a little more at slow/stopped. I then replaced the factory fan with a Muzzy's aluminum fan. That made a big difference for me since it comes on earlier with the new switch. When it comes on you can hear it and feel the heat that you didn't hear or feel before. Last year when we were again having temps in the 105 range I added some Water Wetter and that helped too. It doesn't take but about 4 tablespoons according to the directions on the bottle.

Of course when it gets to these temps here we have high humidity too, therefore I ride very little.

[dna9656]

Your carburetors could also be out of adjustment (usually pilot screw setting). A rich or lean mix will cause higher engine temps and result in unburnd exhaust gasses entering the exhaust making the exhaust at the outlet too hot to hold the back of your hand 1 inch away. On my excellent running '88VR, I can hold my hand at the exhaust flow till I get bored with it all

-Pete, in Tacoma WA USA

 

No brag; just facts here ma'am.

Pete's bike is amazing!

[dna9656]

There is probably no fan that will fit that can get close to matching the ram air through the radiator at 55 MPH. Having the fan on at highway speed can actually restrict airflow through the radiator. On an airplane a spinning propeller is more drag than a stopped propeller.

 

A spinning un-powered propeller has more drag than a feathered propeller. An un-feathered propeller is flat relative to the air stream, you want non-working props feathered (rotated 180 degrees so it's parallel to the air stream) so they induce less drag on the air frame. If we could do that on our bikes MORE air would flow MORE freely through the radiator and that my friends would give you a cooler engine.

You folks in higher temperature zones need to be sure you are running the right oil as well as a good mix of coolant.

[KIC]

On the pilot screw adjustment - does turning it out adjust the mixture to the richer side or the leaner side ? ( I believe out = leaner)

 

If set at 2 1/2 turns out ,should adjustments be at 1/4 turns or 1/2 turn increments ?

[ACE50]

On the pilot screw adjustment - does turning it out adjust the mixture to the richer side or the leaner side ? ( I believe out = leaner)

 

If set at 2 1/2 turns out ,should adjustments be at 1/4 turns or 1/2 turn increments ?

 

No to ( I believe out = leaner)

 

Yes to (out = richer)

Turns to just what you need. No more than 4 turns though, then you need the next size bigger pilots.