Engine Temp Question

[09RappySE]

What do you guys consider "hot" for my R....I have an ESR gauge installed in the return line from the head. When I have been out ridding it has reached as high as 240ish.....is this what you guys would consider a problem? I have contemplated installing the larger rads, but don't want to if I don't really need to.

[El Camexican]

What do you guys consider "hot" for my R....I have an ESR gauge installed in the return line from the head. When I have been out ridding it has reached as high as 240ish.....is this what you guys would consider a problem? I have contemplated installing the larger rads, but don't want to if I don't really need to.

240F on a return line of any engine sounds awful hot if the gauge is correct.

[09RappySE]

That's what I was thinkin....I have to assume the gauge is correct.

[yamaha225dr]

I wouldn't feel comfortable riding it over 210 degrees! There are more factors involved then just the size of your radiator though, coolant flow, air flow through the radiator, the coolant itself and jetting. Any of those can cause excessive temps.

[09RappySE]

I assume the coolant flow is fine, when I replaced the water pump seal the impeller looked fine, there are no issues with air flow, coolant is engine ice....now it is still real fat on the jetting, at the time I was running a 52 pilot and 170 main. I have since dropped the main to 165 and will see how it goes this weekend.

[El Camexican]

That's what I was thinkin....I have to assume the gauge is correct.

Check it with a second gauge. Regardless of whet you find you'll be glad you did. Besides, ASS-U-ME;)

[RIDE-RED 250r]

What coolant/water mix are you running?? Straight coolant will cause it to run hotter if you don't cut it with water.


FWIW, ESR recommended running 80/20 water/coolant mix in my big bore....

[threewheelin-feelin]

What coolant/water mix are you running?? Straight coolant will cause it to run hotter if you don't cut it with water.


FWIW, ESR recommended running 80/20 water/coolant mix in my big bore....

these big bores dont seem to like the hot weather at all. not that ita surprising. i do not have a gauge on my 310 but mine was getting hot enough it was blowing coolant out the overflow when i was drag racing at busco beach 2 weeks ago. i guess it was to be expected we were waiting in long lines to race and it was very hot out. my buddies yzf450 and crf 250 were both over heating as well. so what kind of riding were you doing? i was thinking of rigging up some kind of a fan setup on mine

[RIDE-RED 250r]

these big bores dont seem to like the hot weather at all. not that ita surprising. i do not have a gauge on my 310 but mine was getting hot enough it was blowing coolant out the overflow when i was drag racing at busco beach 2 weeks ago. i guess it was to be expected we were waiting in long lines to race and it was very hot out. my buddies yzf450 and crf 250 were both over heating as well. so what kind of riding were you doing? i was thinking of rigging up some kind of a fan setup on mine

Probably the reason ESR recommends an 80/20 water to coolant mix... More water will help it run cooler. It does make a difference.

I remember reading many years back, maybe in a magazine article or something like that, most older school liquid cooled 2-strokes can overheat if you simply let a fully warmed up engine just sit at a dead idle for too long without revving the engine a bit. I remember hearing something about the impeller on the R's not being really effective at pumping coolant at idle RPM's. Now add to that the fact these old hot-rods don't have electric fans that kick on like the newer stuff. Gotta keep a little wind flowing through those rads and run an effective coolant mix....

[threewheelin-feelin]

at the moment i have straight water in mine

[El Camexican]

Probably the reason ESR recommends an 80/20 water to coolant mix... More water will help it run cooler. It does make a difference.

I remember reading many years back, maybe in a magazine article or something like that, most older school liquid cooled 2-strokes can overheat if you simply let a fully warmed up engine just sit at a dead idle for too long without revving the engine a bit. I remember hearing something about the impeller on the R's not being really effective at pumping coolant at idle RPM's. Now add to that the fact these old hot-rods don't have electric fans that kick on like the newer stuff. Gotta keep a little wind flowing through those rads and run an effective coolant mix....

My 300EXC would make you sick. It has no overflow tank and in some 250 hours of running time in the desert at 100+ temps and it has never lost a drop of fluid other than on day one when I over filled it. Now on the other hand my Tri-Z gets hotter than the 300cc bike ever has after about 5 minutes of idling. :( I can't imagine what kind of heat a 330cc Yamaha makes.

[threewheelin-feelin]

the main problem is the lack of a fan. i never had this issue with mine when it was still 250cc. i didnt have this problem the last two times i went racing after i istalled the 310 kit when it was much cooler. the problem was sitting in one place at idle to long waiting to get to the line in 90 degree weather. if i had a fan i wouldnt have this problem

http://www.ebay.com/itm/Universal-Motorcycle-Dirt-bike-Cooling-Fan-Kit-CR-F-YZ-F-KX-F-RM-Z-SX-MX-/160939242073?pt=Motorcycles_Parts_Accessories&hash=item2578b9f259&vxp=mtr im thinking about trying to find two fans this size on both side and just put them on a toggle switch. im guessing my 200watt stator would power them

[09RappySE]

After talking with tom at ESR, he seems to think my issue is a lean condition...so he had me change my jetting to a 50 pilot, 175 main and move the clip to the bottom of the needle, and get a good plug chop this weekend, he also recommended a 80/20 coolant mix, I am curently running straight engine ice. The more I think about it, we were doing some tech trail ridding that day, so it may have been lack of air flow to the rads... I also looked at my plug, which to me shows a tad rich, not lean....he said it is also possible that the crank seal is leaking letting trany oil into the crank case causing a false rich indication, we will see how the jet change and plug chop works out this weekend.

Let you know how it works out.

[09RappySE]

Check it with a second gauge. Regardless of whet you find you'll be glad you did. Besides, ASS-U-ME;)

I hear ya....and you are not wrong, this is good advice, will do when I get a chance.

[barnett468]

Hello



MIXING COOLANT- As far as mixing you can use 80% water with 20% engine ice and can add deionized water in place of tap water and 1/2 bottle of red line water wetter. Engine ice has 3% deionized water by weight and deionized water is slightly more effective at cooling and less corrosive than tap water.



ENGINE ICE INSTRUCTIONS – It says “ready to use” on the label however it should be mixed at a 50/50 ratio because it is 95% antifreeze just like any other antifreeze that is not pre mixed with 50% water.



TEMP GAUGE - As far as another temp gauge you can buy an infrared. See link below.



BIG BORES RUN HOT - As mentioned by another above, if you have a big bore kit on a 250 etc it will typically run hot. The reason you don’t frequently hear about them running hot is because most people don’t have temp gauges and the anti freeze prevents them from boiling over, lol.

The radiators on the 250r’s and Tecates are barely big enough to keep 250cc’s from overheating under hard riding conditions in the heat of summer. Boring simply makes them run hotter which overwhelms the system. Bigger bores needs more water capacity and more cooling area ie more cooling tubes in the radiators.



SLOW RIDING


we were doing some tech trail ridding that day, so it may have been lack of air flow to the rads.

Yeah, that's not good for a big bore. Just remember your car has a fan your poor bike doesn't.



SPARK PLUG – If you run an 8 switch to a 9 [not Champion].



IGNITION – Try retarding it 2 degrees, if it runs hotter return it to stock.



COMPRESSION – Compression generates power which in turn generates heat, the more compression/power you have the hotter your engine will run. If you have a cylinder cranking pressure higher than around 185 than it’s higher than it needs to be for non racing apps. If your compression is like 195 or more you can reduce it either by installing a thicker head gasket if available or having the cylinder head remachined.



JETTING – You’ve got that covered.



ENGINE ICE MSDS HAS 3% WATER 95% ANTI FREEZE 2% PROPRIETARY [probably water wetter]

http://engineice.com/msds_engineice.pdf


PRESTONE 50/50 MSDS HAS 50% WATER 50% ANTI FREEZE

http://econtent.autozone.com:24999/znetcs/msds/en/US/391379


WATER WETTER MSDS

http://www.redlineoil.com/content/files/tech/MSDS%20WaterWetter%206-11.PDF


INFRA RED TEMP GUN

http://www.ebay.com/itm/New-Point-Design-Ir-Infrared-Digital-Meter-Thermometer-Temperature-Gun-Gauge-/171062112705

[RIDE-RED 250r]

All good points Barnett...


The big bore makers did increase coolant capacity to a degree with enlarged coolant jackets on the exhaust side of the cylinder. I'm not sure by how much or how significant it is, but if you look at a big bore cylinder compared to OEM on a 250r, there is a pretty big difference..at least by looking at the outside of the cylinder casting anyway.

My 250 will run pretty hot when riding slow or if idled too long. Just how hot I cannot tell you as I do not have temp gauges yet. I just know it gets hotter in those situations, lol!

[yamaha225dr]

I need to get one of those temp gauges for my 250r! A local motorcycle store sells those ESR in line gauges and I have been eyeballing them. My 250r doesn't seem to get extremely hot but I try to ride at a good pace all the time to keep temps down and usually let it cool down a little after every hour of riding.

[JasonB]

I run an inline gauge on my 310 ESR motor that sticks out the left side fender flares so I can peek at it. I run between 150 and 230 depending on riding conditions and outside temps etc. at home in spring/fall i see about 150-200. out at the imperial invasion in march in california in the sand i was seeing 230 or higher and kept shutting it down because i didnt want to hurt the motor. I think around 250 degrees is where things start melting/breaking, atleast thats what i heard. i ran a 50/170 combo in my 39pwk at home and in MI/IN for rides, but in the sand i jumped up to a 52/178 combo to make sure it was rich enough to not melt. more fuel=safer when you have higher temps and load from my understanding, please correct me if im wrong!

[barnett468]

Hello





All good points Barnett.

Thanks, I unfortunately have had more experience than I'd like with these issues which include overheating vintage cars etc, lol.







The big bore makers did increase coolant capacity to a degree with enlarged coolant jackets on the exhaust side of the cylinder.

LARGER CYLINDER WATER CHAMBERS – Thanks for the info RIDE-RED 250r, I didn't know that. Yeah, that’s a small help and better than nothing and all they can really do but better rads and/or fans really are the ultimate cure. The increased water capacity needs to be in the rad providing the cooling passages in the cyl are large enough. Here's a bad analogy just for those that don't know this, imagine a heated 5 gal can [a car engine] of 210 water cycling 2 gpm through a 12"x12" radiator and big fan, the water coming out might be around 10 degrees cooler. Now imagine that same can with your cars big radiator and the same big fan, the water coming out might now be 60 degrees cooler.






COOLING FANS - They actually make small 4” diameter light weight 12V fans that one could attach to their rads for improved low speed cooling if they really had a problem.






CYLINDER HEAD MOD – I actually came up with a simple idea when I worked at Kawi which was to add fins to the top of the head just like a non water cooled head has. This would actually help noticeably reduce temps especially at higher speeds. One can easily get some 3/16” thick 6061 aluminum and cut a bunch of fins 1” high and weld them on the head around 1/4” apart.

We had cooling and detonation problems [yes the stockers still detonate] with the 84 Tecate prototype and I told them that adding water cooling was a good idea but that they defeated most of their purpose by removing all the cooling fins on the engine, so they didn’t necessarily make it better by adding water cooling they mainly just made it different, lol.






TAPERED AIR DAM – One of these could easily be made to direct air over the newly finned head[ it won't cool a stock water cooled head simply because there are no cooling fins on it, lol]. Cylinder head temps have been measured with and without the dam and the reduction in temp with it were substantial at higher speeds. Harry Klemm ran one on his unbeaten AHRMA Kawi H1 until his jealous competitors that were trying to compete against it with 500 cc BSA's complained to AHRMA saying it gave him an aerodynamic advantage, lol. If anything it was an aero disadvantage because it blocked the flow of air around the bike, lol. He still beat them without it.






SPARK PLUG HEAT SINK – Providing it will clear the head one can also take a solid 1" - 1 1/18" round bar aluminum and machine a hole .0005 larger than the shaft of the plug, then machine 1/8” wide fins 3/16 apart .200 deep and as tall as necessary and simply slip it over the plug shaft.







My 250 will run pretty hot when riding slow or if idled too long. Just how hot I cannot tell you as I do not have temp gauges yet. I just know it gets hotter in those situations, lol!

Well maybe the easiest fix is to have 09RappySE remove his temp gauge, lol.

[RIDE-RED 250r]

Well maybe the easiest fix is to have 09RappySE remove his temp gauge, lol.


LOL! That'll work! ;)

I have a temp gauge...the back of my hand! LOL!

I do sometimes find myself riding slower more technical trails on my R's from time to time. I have pondered installing fans on my rads. With the R rads being taller and skinnier like a dirtbike, I would think you would want 2 fans behind each rad to effectively pull air through the most possible radiator surface. One fan mounted high and the other low....

But, I think it would be a bit tricky trying to mount it all up, there's not a ton of clearance behind the rads and ahead of the tank. Then the tank mount brackets I would think would be a bit of an obstacle...

Then, what little I know about electrical.. It's not so much the running draw the fans pull on the electrical system, but the startup draw. Wonder if a high output stator would be required??

I like the idea... No fancy temp sensors needed, just a toggle switch. Flip em on if you find yourself on a slower, more technical trail, or waiting in line at that drag race.

Wonder if anyone has done it.....

[kb0nly]

If you decide to fans on it don't waste all your money on those so called kits... All they come with is a basic 12v 120mm fan and some have a thermostat some are just a switch. You can buy much higher flow 12v fans then the ones in those kits. I deal with these muffin fans a lot, computers, equipment racks and cabinets, etc. If the radiator is large enough get a high flow 200mm 12v fan, that would make a significant difference. There is also 12v fans for transmission coolers, they come in 6" and 8" sizes and they move a couple hundred cfm. Get the highest airflow muffin fan you can fit. The trike should be able to run it fine as long as you have a DC trike, if you don't have a rectifier/regulator then you will have to wire one in also to run the fan.

[barnett468]

Hello



I do sometimes find myself riding slower more technical trails on my R's from time to time. I have pondered installing fans on my rads. With the R rads being taller and skinnier like a dirtbike, I would think you would want 2 fans behind each rad to effectively pull air through the most possible radiator surface. One fan mounted high and the other low…

WHEN WILL A FAN HELP, WHEN WILL IT HURT AND FAN PHYSICAL SIZE

These small fans might not flow enough air to run 2 on each rad at speeds over 35 mph, one would need to test then with a temp gauge. Since no one in their RIGHT mind trail rides a 250r 100% of the time, one can get away with a small fan covering only around 50% of the rad. One of the reasons a full fan is not absolutely necessary at low speeds is because these bikes were sort of designed not to overheat when ridden at lower speeds with little air flow thru the rads. We’re using them in this case to compensate for the extra heat generated by people boring out their bike to the max or installing a cylinder size that was never designed to be on there and therefore can’t be cooled properly by the existing system. An engine running at low speeds generates less heat than one running at higher speeds therefore the low speed cooling requirements are less.

By only covering 1/2 of the radiator with a fan it still allows 50% of the system to function as designed at all speeds.

With a fan mounted in front of the rad your bike should not run hotter than designed until you reach speeds of around 35 mph. Speeds above 35 mph should not be maintained for more than maybe 5 minutes unless bike has a temp gauge one can monitor.

With a fan mounted in back of the rad your bike should not run hotter than designed until maybe 55 mph. Speeds above 55 mph should not be maintained for more than maybe 2 minutes unless bike has a temp gauge one can monitor.







I like the idea... No fancy temp sensors needed, just a toggle switch. Flip em on if you find yourself on a slower, more technical trail, or waiting in line at that drag race.

You would have to get a temp gauge, then determine the effect of the fans in the off vs the on position at higher speeds like 35 on up.







But, I think it would be a bit tricky trying to mount it all up, there's not a ton of clearance behind the rads and ahead of the tank. Then the tank mount brackets I would think would be a bit of an obstacle...

You could always build my custom finned cyl head and scoop, you’d be the first bone to have it, lol.






WILL A FAN DAMAGE MY RADIATOR

Let’s hope not, lol. A properly mounted fan will not damage your rad, they never do on the baja trucks. Even if your fan slips on the rad it will only damage the cooling fins slightly, it will not damage the tubes because they run vertical and therefore run in the same direction as any potential fan slippage. That being said, lighter is better, so I would try to stay under 2 lbs which most 6” fans are under.






BEST MOUNTING LOCATION

The lower the better. Mounting in front can obstruct air mainly at higher speeds like maybe 35 mph. Mounting them in the rear still blocks a little air flow but it blocks substantially less than front mounted fans.






HOW TO MOUNT FAN TO RADIATOR

Go to your local auto parts store or NAPA or Pep Boys, they will have or can order fan mounting kits. You can also go online and to hayden and buy them. They are simply 4 plastic ties and 4 small squares of ¼” thick rubber pads, lol. The ties go thru the fan and cooling fins on the rad and attach with a large plastic washer on the opposite side. Cheesy but effective.






WHAT TYPE OF SYSTEM WILL THEY RUN ON

They will run on ANY bike that has a 12V A/C charging system that has a regulator and enough amps to run the fans [and lights if you plan on running both simultaneously]. It’s no different than your car. I don’t know if they will run on other types of systems.







Then, what little I know about electrical.. It's not so much the running draw the fans pull on the electrical system, but the startup draw. Wonder if a high output stator would be required??

One would have to call the fans mfg for this information.





FAN POWER REQUIREMENTS

This is a bit of a gray area of discussion and I am NOT an electrician. I am an electrical HACK, lol. That being said some of the following info may be incomplete, poorly explained and/or just slightly inaccurate. A 12 V 20 amp fan will run on ANY voltage ie 6, 12, 24 etc. Running on voltages other than that which it was designed for may damage the fan.






EXAMPLE - A 20 amp fan will run on slightly less amps than it was designed for up to a certain point, it will simply spin slower with less amps. A 2 speed fan will run on around 50% less amps on the low speed position and at around half speed. The electric fans in newer cars have two speeds, the speeds are controlled by changing the amperage to the fan, not the voltage.






HOW MUCH AMPERAGE DOES MY CHARGE COIL PUT OUT

Check the ohms, then check the voltage at idle and high speed, then take the voltages and divide them by the ohms, the results are amps.

An 85-86 250r alt has from 0.1 – 1.0 ohms of resistance per manual. IF, it produces 50 volts then the amperage would be:

50 V div by 1.0 ohm = 50 amps = happy can use fans

50 V div by 0.1 ohm = 5 amps = unhappy, can’t use fans






HOW MANY AMPS DOES MY HEADLITE USE

If you run fans and lites simultaneously this number must be taken into consideration and subtracted from the out put of the alternator. If your 2 fans need a combined total of 30 amps and your lites need 5 amps and your system only puts out 30 amps then your lites will be slightly dimmer than normal and your fans will run slightly slower, that’s all. No damage will be done to anything.






WILL I NEED A DIFFERENT REGULATOR

Possibly.






HOW DO I DETERMINE WHICH FAN IS BEST

I have found that most the fan mfg’s outright LIE about the CFM they flow so I simply go by how many amps the need. The more amps they draw the more CFM they will flow in general. There is no such thing as a new fancy whazoo fan blade that flows a ton more air with less power than another. If this was the case, a prop on an airplane would look drastically different than they do now, however the last time I looked they look about the same as the one the Wright brothers used, lol. Spal and Derale are two of the best and lie the least.






CAN I REWIRE MY ALTERNATOR IF I NEED MORE AMPS

It depends upon its design and possibly available room etc. See calculator below for a guide.

http://www.rapidtables.com/calc/electric/watt-volt-amp-calculator.htm






WHAT DOES PUSHER AND PULLER FAN MEAN

A pusher is a std fan that blows air and is mounted in front of the rad. A puller fan pulls air and is mounted behind the rad.






WHICH FAN BELOW IS BEST

For behind the radiator the 500 cfm 5.9” Spal puller type.

For in front of the rad the 300 cfm 6” spal pusher or the 348 cfm 7.9” spal pusher type.

If you want a 2 speed fan the only one available is the Derale 315 cfm 6”x2 ¼, 3.6 amp puller straight blade 2 speed Ship wt 2 lbs






FANS Sorry this area is a bit of a mess.

Spal puller fan 300 cfm 2.5 amp 4 position mount 6” x 3.92 x 5.6 blade

http://www.racerpartswholesale.com/product/2100/SPAL_Fans_1


Spal pusher fan 307 CFM 3 position mount, round 6.842” x 2.267 5.2

http://www.summitracing.com/parts/spu-ix-30103013/overview/


spal 500 cfm 5.905 x 3.959 5.6 10 blade ix301000291 puller 2.5 – 3.4 amp 1.17 lb

http://www.summitracing.com/parts/spu-ix-30100291/overview/


348 cfm 7.952 x 2.011 7.5 ix 301000393 pusher

http://www.summitracing.com/parts/spu-ix-30100393/overview/


spal 431 cfm 7.92” puller

http://www.summitracing.com/parts/spu-ix-30100394/overview/


spal 301 cfm 7.015 x 2.011 6.5 pusher

http://www.summitracing.com/parts/spu-ix-30100403/overview/


spal 366 cfm 7.9 x 7.5 2.011 puller

http://www.summitracing.com/parts/spu-ix-30100358/overview/


Derale 315 6x2 ¼ 3.6 amp puller straight blade 2 speed Ship wt 2 lbs

http://www.etrailer.com/Radiator-Fans/Derale/D16105.html


Derale 315 or 325 cfm same as above? Curved blade but includes toggle switch for 2 dollars more.

http://www.etrailer.com/comparison.aspx?pc=D16105&pc2=D16505


Derale 400 cfm 7 1/4x2 3/8 3 lb $74.00 4.8 amps ship wt 3 lbs heavy

http://www.etrailer.com/Radiator-Fans/Derale/D16617.html

[threewheelin-feelin]

rappy my 310 has settled i n pretty good at a 170 main jet. the needle is in the stock setting and the pilot is stock. you dont know what the pilot is stock do you? ive never had the bowl off. i really doubt you have a lean condition. i feel very confident its the lack of fans and air flow that was doing it to you

[09RappySE]

Just got back from a very fun weekend. brought the raptor...but never even rode it....was having way too much fun on the R.....I ended up with a 170 main and 50 pilot (48 was stock from ESR) needle is in the 3rd spot from the top, plug shows maybe just a tad on the rich side, but I will leave it that way, she runs great and my temps never got above 175 all day....most of the time about 150. I did plenty of trail ridding, but kept the speed up.... I am happy with those temps and see no need for a larger rad at this time. Thank you all for the help.

[barnett468]

Hello 09RappySE


Yeah, those temps are killer, good for you!

[RIDE-RED 250r]

Gotta keep em rollin' Rappy! :beer