Hot weather riding, engine temp

[bobcat]

On regular days, it is acceptable. Stand still traffic gits me worried when that guage starts to climb. Yea, I hear the fan kick on.

 

I wired an off/on switch directly to the fan so I can turn the fan on whenever I want like in the situation you described.....This way I don't have to wait for the engine to get too hot before the fan kicks in...

[Gearhead]

Well, I don't think the engine is "too hot" per se when the fan kicks on. Per the manual, the ON temp is about 220F which is not bad for the engine. What I find a little disturbing is that when cruising on the Interstate at high speed on hot days, the fan is on somewhere from often to always. I know high speed puts the engine under more load, but it also should cause increased convection over the radiator without the fan. This makes me wonder if the radiator is getting sufficient airflow behind the front wheel at speed, or maybe if it's a little on the small side. Those little scoops on the sides of the grill, I don't think they're there for looks, I think the engineers needed a little more air flow at speed. And in the desert, it may need a little more still.

 

I also find it puzzling that I get 2.5 mpg lower mileage in the heat on average, sometimes worse. I compiled numbers from the last year to determine this; it's not just some off-the-cuff wag. I mentioned in London Greg's mileage post that sometimes average mileage would just go up or down for no apparent reason; well, I've correlated it to Autumn and Spring. Don't know if that's due to intake air temps or coolant temps.

 

Nothin' wrong with turning the fan on sooner, though. Maybe it would help mileage. More load on electrical system, though.

 

Squeeze, I have nothing conclusive yet. I haven't installed a decent temp gage. I did change the coolant to about 20 or 25% antifreeze, the appropriate amout of Water Wetter, and the remainder distilled water. I don't think overall running temp is affected, but Water Wetter's main claim is reduction of "hot spots" in the head which is pretty hard to measure. It's possible that such hot spots cause more pinging which could reduce mileage, increase temp and not be good for the engine. I have run about 4 tanks of gas since this change and mileage MIGHT be up, but need more data before I'll commit to that. I still notice light pinging under certain conditions; can't say if it's reduced or not.

 

I did pull into the garage one hot day with the temp gage at 2/3 and the fan running and got out the IR thermometer. I shot it at the alum collector where the switches are, as you suggested, but I didn't take the time to remove the side cover first so I shot through the triangular piece of grating that covers it. I measured about 196F, which sounds too low. Maybe the grating affected the reading. Then I shot the upper tank of the rad and got about 208F.

 

Tucson is now in full summer swing, which is to say it's freakin' hot, so I have plenty of opportunity to test stuff. I'll give a mileage report after a few more tanks. I may try extending the scoops on the grill. I never did call about a thicker core replacement.

 

Jeremy

[mraf]

Anyway, I'm not itchin' to mount another radiator or whatever just yet, just thinkin'. I think I'm gonna replace the t-stat for good measure,

Jeremy

 

If you do change the thermostat with the NAPA one make sure you ask for the heavy duty one. They make a standard and a heavy duty in that number. If you hold the standard up to the heavy duty one you can see the difference between the two. I had to drill my own steam hole {For want of a name for it} in the NAPA one before installing it. I rigged up a toggle switch to turn the fan on myself if I ever think the motor is getting to hot. If nothing else it's a peace of mind kind of thing.

[Gearhead]

I did change the coolant to about 20 or 25% antifreeze, the appropriate amout of Water Wetter, and the remainder distilled water. I don't think overall running temp is affected, but Water Wetter's main claim is reduction of "hot spots" in the head which is pretty hard to measure. It's possible that such hot spots cause more pinging which could reduce mileage, increase temp and not be good for the engine. I have run about 4 tanks of gas since this change and mileage MIGHT be up, but need more data before I'll commit to that. I still notice light pinging under certain conditions; can't say if it's reduced or not.

 

 

I've run some more miles and I do not think my mileage is improved due to the Water Wetter as I suggested above. With the limited resolution of the stock gage, I can't tell that it's running any cooler than BWW (Before Water Wetter). And as I said there is still light pinging under low RPM heavy load. I'm going to run a few tanks with Premium and see how that does - it could reduce pinging which could affect mileage.

 

BUT - one thing I have noticed: BWW, I had it happen that the coolant overflow tank would fill up to the top, which is a good 2.5" above the FULL line. This happened when riding home on a hot afternoon, some Interstate riding, finishing with my dirt road where the radiator doesn't get much airflow. I thought that seemed like an awful lot of coolant expansion. Since changing the coolant as described above, that has not happened. The level when hot only rises maybe 3/8" in the overflow tank. So either this coolant mix expands less than 50/50 with no WW, or the localized boiling was causing excessive overflow, or something.

 

Jeremy

[mbrood]

I was looking for a difference in parts for the temperature sender and the temperature switch between an 84 and an 86... they seem to show the SAME temperature sender but a whole different temperature switch... yet BOTH bike manuals say the switch kicks the fan on at 105C and kicks back off at 98C.

 

Looking at the Yamaha parts break-down:

1984...

11H-82560-00-00 THERMO SWITCH ASSEMBLY ($56.80 US price)

11H-83591-00-00 THERMO UNIT ($24.70 US price THIS is the temperature sensor for the gauge)

 

1986

2EL-82560-00-00 THERMOSWITCH ASSEMBLY superseded with # 3LN-82560-01-00 ($23.27 US price)

11H-83591-00-00 THERMO UNIT ($24.70 US price THIS is the temperature sensor for the gauge, same item as above)

 

 

 

Anybody know the difference?

[Numb Knuckles]

I had a Willys Jeep in high school (Oh the memories) when I lived in AZ. I chased an overheating problem for a long time - new thermostat, water pump, oversized radiator, different coolants... The cure stumbled upon me when I rebuilt the carb. There was a vacuum leak between the carb and the manifold. The temp dropped by 40 degrees and never overheated again.

Good luck, Gary

[DRAGIN TAIL]

I tried Water Wetter and it did improve the position of the needle a little. On a hot day I previously was almost to the red area traveling at high speeds for serveral miles. Now there is an 1/8" more green showing. I put about 3 ounces in and am considering adding more but think I'll first tear into the water pump and see if the impeller is worn, if it's plastic. I'm in the process of adding a Champion Sidecar and need a little relief.

Ronnie

[Condor]

Before our Tahoe dayride I went ahead and flushed the radiator on the '83. I'm not sure when it was done last, but I've owned the scoot for 3 years, and I'd never done it. I had some extra GM orange coolant designed for their aluminum headed engines, and decided to give it a try. I think it ran around $19.00 bucks per gallon when I bought it for the Suburban. Tossed in the recomended mix of 50/50 water/coolant and some water wetter...just because...and while on the ride I noticed that the temp guage didn't run quite as high and it cooled down a lot quicker than it had in the past. So I'm happy with the results, and will probably continue to run the same mix in all my bikes. Oh yeah, BTW, I found the drain valve already turned to the on position when I started the flush, so I'd been by-passing the thermostat all this time. After filling the radiator, I turned it off, and by the movement of the coolant the thermostat did open up and fluid started to circulate. I wonder if the valve being open caused the coolant to circulate too fast and not cool down when running thru the radiator???

[Venturous Randy]

Condor, with your last comment, I believe you hit the nail on the head. On our bikes, as with most cars, under load, the engine will not run cooler with the thermostat removed or in our case, with the by-pass being open. The water does go thru the radiator too fast to be cooled properly. For those of you that do not know, when looking at the hex on the by-pass valve that is at the lower part of the cooling system on the front of your engine, The top of the lettering should be point in the 5 O'Clock position.

A while back while doing some work on my 83, I inadvertently left my by-pass valve in the open position. I noticed that something was wrong because it was taking longer for the bike to get anywhere near the normal operating temps. I also noticed that under load, as in pulling the camper or running interstate speeds that it ran hotter than normal. When I realized my valve was left open and when I closed it, everything went back to normal.

Two other factors that will affect engine temperatures is having the carbs in sync and not having a restriction in the carb pilot jets. Either can cause a cylinder or two to run lean and that will definitely tax your cooling system.

RandyA

[Guest mytquin007@aol.com]

again i go to e bay and i have bought a steel 6 blade fan from MUZZYS (no sure but think stock is 5 or 6 blade) Stock is plastic. havent installed it yet to let you know only $30 so worth a try they claim it works better than stock

MUZZY also makes mufflers and other race pieces

MIKE Q:225:

[Condor]

A while back while doing some work on my 83, I inadvertently left my by-pass valve in the open position. I noticed that something was wrong because it was taking longer for the bike to get anywhere near the normal operating temps. RandyA

 

Randy, I think a lot of folks are confused about which position the valve needs to be in. On or Off. For normal everyday operation the valve needs to be in the OFF position, and when draning the radiator the valve needs to be turned ON. The positions are marked on the head of the hex, but are a ***** to read unless really clean. Some housing have an indicator arrow and some do not, but the position is about 2:00 o'clock on the housing. IT's fairly easy to tell if the valve is in one position or the other by the ball dent. They can 'feel' the ball when it hits the indent and is in the right spot.... I hope this helps a few folks. I was in a fog until I tore one apart to see what was going on.....

Edited July 6, 2008 by Condor

[Venturous Randy]

Randy, I think a lot of folks are confused about which position the valve needs to be in. On or Off. For normal everyday operation the valve needs to be in the OFF position, and when draning the radiator the valve needs to be turned ON. The positions are marked on the head of the hex, but are a ***** to read unless really clean. Some housing have an indicator arrow and some do not, but the position is about 2:00 o'clock on the housing. IT's fairly easy to tell if the valve is in one position or the other by the ball dent. They can 'feel' the ball when it hits the indent and is in the right spot.... I hope this helps a few folks. I was in a fog until I tore one apart to see what was going on.....

I agree. Now turn it to where the picture does not show it up-side down and the top of the letters should be toward the 5 O'clock position, right?

RandyA

[Condor]

I agree. Now turn it to where the picture does not show it up-side down and the top of the letters should be toward the 5 O'clock position, right?

RandyA

 

 

Yep, your right Randy. Just like in the pic. Ain't editing great!!

 

BTW, the pic shows the valve in the OFF position. So if anyone has to stand on his...or her head to read the lettering you're A-OK....

[cmiles3]

There's a bypass diverter, that circulates a portion of the coolant through the engine without going through the radiator. If you set it wrong, it causes problems. I don't think mine is set right. Read this in another post, so a search may find the thread with the correct settings.

[Ndiaz]

I'm a "new" Venture Royale owner, a white 1988. I've been following this thread and learning a whole bunch from you guys. I want you to know how much I appreciate your "conversation" on this topic.

 

Nick Diaz

Middletown, MD

[Condor]

These things happen all the time Nick. Lots of things to learn just by hangin' out....

[Tommy1966]

Does anyone know the size and thread pitch on the thermoswitch for an 83? I have a chart for all the NAPA fan switches and specs but need to know what size the factory switch is. Thanks in advance for the help

[mralex714]

Does anyone know the size and thread pitch on the thermoswitch for an 83? I have a chart for all the NAPA fan switches and specs but need to know what size the factory switch is. Thanks in advance for the help

 

Does this help?

http://www.venturerider.org/forum/showthread.php?t=72253