How hot is too hot?

[Kev250R]

Nah, let's keep it going. I appreciate the real experiences people have had. This is how we learn from each other.

Agreed

 

[Kev250R]

AGREED, NEWER BIKES DO RUN HOTTER, the lean ass fuel injection protocols are to blame for a lot of it.. and they are designed to take it for the most part. My old KTM390 was ridiculous, but survived just fine as well. was like what, 14:1 compression or something. But it physically ran hot.

as far as radiator fans, if they can't move enough air to continuously cool a radiator/motor down to an acceptable range, its undersized and should be dealt with, period. The old c10 concourses were notorious for this.. i know, i owned 2. the 1st thing i did with my KTM from above was fit an spal fan that cooled the motor down quicker because it moved a bunch more air.

want to run it a bit cooler? run an eife unit throw a bit more fuel in there and get the afr targets down to 13.5-13.8.

I'm with you, I think it's rising emissions standards which have a lot to do with higher compression ratios and running leaner then they used to.

Adding a second fan to the other side of the radiator is a common upgrade for the 990's. I've yet to do it on mine though as *most* of the time it's ridden on the highway and much of that time my water temp stays at or just below normal. Getting stuck in traffic and using the hydraulic clutch excessively really drives the water temps up quick on that bike though so I try to avoid those situations whenever possible. Bonus that it's legal to split lanes here in Ca so if it's safe I'll generally do that to save sitting and idling.

When I was shopping for my Duke I *almost* bought a 390. If I'm honest it was a little too hard-core for me, for what I was looking for at the time. My 200 Duke is my first Sport bike and I wanted to see how I was going to like them before going all-in on a 390. 1.5 years later and I'm liking it, though my Duke gets ridden the least and the least amount of miles of my street-legal bikes, although I live 15 minutes from a popular canyon road here in So.Cal. and enjoy ripping through there when I have a free minute. A friend recently commented that he could probably take the number of miles on my Duke (less than 1,000) and divide it by the distance from my house to where I turn-around at in the canyon and figure-out how many times I've ridden through there LOL! He's not wrong as it is a popular destination for me when I'm on that bike.

 

[Clancy oto]

When I was riding my ct110 in Alice springs, one of the hottest places in the middle of Australia I asked the same question to a mechanic friend re overheating. He said a 45 degree day will still suck the heat right off a 400 degree engine. I’ve never worried about my air cooled bikes since. Don’t know what that is in Fahrenheit but summer there is bloody hot and the CT never missed a beat.


Sent from my iPhone using Tapatalk

 

[p1eric]

Don’t know what that is in Fahrenheit but summer there is bloody hot and the CT never missed a beat.

45 C = 113 F. That's hot!

Not knowing anything about Alice Springs I looked up the average high temp and it is almost identical to where I am in north Texas. Alice Springs wins on the max temp though by a few degrees. There are some real scorchers down there.

 

[p1eric]

My buddy rode-up next to me and said "My bike is overheating and yours is too stupid to know it's overheating!"

This is a great line and almost the same thought I had except wondered if I was too stupid to know it was overheating.

 

[Kev250R]

This is a great line and almost the same thought I had except wondered if I was too stupid to know it was overheating.

Thanks! We actually joke about it often, especially since he's gone through three bikes in the five years since that incident and I'm still putting-along on my TW (and soon my Trail!)

 

[m in sc]

yeah, int he grand scheme of things, there usually has to be something pretty wrong to overheat one to the point of not being 'ok'. Look at how many of similarly designed machines are used in SE Asia and S America for transportation. crap fuel, legit off road daily use, etc.

 

[STUBBORN]

Thank you very much for your purchase. This gauge is a replacement for your existing oil cap. Just unscrew the stock oil cap and screw this one and leave it permanently on your bike. It functions as an oil temp gauge and a showpiece instead of an otherwise boring looking oil cap, but it doesn't have a long dip stick that can measure your oil level. Modern bikes usually come with an oil sight window so the dip stick is becoming obsolete. If your bike doesn't have an oil sight window, you can keep your stock oil cap at home and use it to measure oil level from time to time.

How this oil temp gauge works is it relies on engine pressure which splashes oil everywhere when the engine is running to measure the oil temperature. When the bike is parked and its engine is cool, the gauge measures room temperature. CT125 engine is small so the temp usually reads between 60-80 Celsius, if one day, you find that the temp reads abnormally higher than this range, you can assume that engine oil might leak or disappear below the recommended level. Or in case of water cooled engines, something wrong with the coolant level, the fan, or oil level.​

Why do I have to keep the old Oil cover?
Why can't this temp meter have a measurement stick?

 

[p1eric]

Why do I have to keep the old Oil cover?
Why can't this temp meter have a measurement stick?

Just a guess -- the same temp gauge may work for other motors that don't have a dip stick, so you'd need to keep the old cap with measuring stick on hand for when you want to check the oil level. The Trail has a dipstick separate from the oil cap, so you shouldn't need the old cap.

 

[m in sc]

id be leery of that thing. Probably not clearance for dipstick as its too close to the clutch on the trail.
i had one of these setups for oil on the grom, then when i motor swapped i got a water temp one and its great. plugs into the stock oil temp sensor(same as the trail). https://www.steadygarage.com/store/opmid-thermometer-and-voltmeter-plug-play-honda-monkey-grom-125

 

[STUBBORN]

Just got the oil temp guage first class mail. Firs & Works good. Probe only goes in a jusy little bit. There is a separate dipstick. I was thinking of old Honda Super Cub.

 

[DJ427]

I'm a retired mechanical engineer, I've built everything from minibikes to racecars, but that doesn't mean I know anything. Seems to me the short thermocouple on that little guage will get fresh oil splash almost continuously when the motor is running, the temperature at that point is a good measure of whats going on in the crankcase. It will always give you the most optimsticly cool estimate for the oil temp in general. And remember, def F is simply deg C divided by 5, then multiply by 9, then add 32. While riding my bikes I keep an eye on the oil temp guage, I have a hotrod, it has a VDO oil temp guage. The temp of the trail's oil is just about the same as the temp of the hotrod motor... around 105 deg f typically, depends on your climate and atmosphere

 

[m in sc]

i think the filler cap gauge is a decent comparative tool. thats about it. where it is normally to where it is when something goes wrong. as far as an actual accurate temp reading... id again be leery if its not in an actual oil bath. this is why oems will typically put oil temp sensors in the oil pans or in an oil galley passage. the oem one on the grom/monkey/trail motor sees a more constant flow back thru the timing chain channel. while not ideal its good enough for the ecm to use, and IMHO thats def better .02

 

[Cpd419]

I’ve owned a lot of air cooled bikes and have never had one overheat and I’ve ridden them in some really hot weather. And a lot of city stop and go back in the day. I’m running no ethanol gas which may run a little cooler? Maybe I’m wrong.

 

[DJ427]

I’ve owned a lot of air cooled bikes and have never had one overheat and I’ve ridden them in some really hot weather. And a lot of city stop and go back in the day. I’m running no ethanol gas which may run a little cooler? Maybe I’m wrong.

Zero ethanol gas is a must have if you can get it. Quite important to keep things running

 

[Thepen]

I on the other hand run 80-85% ethanol, aka e85 in this bike. Dropped my temps by 20-30*f , but then again I use this bike as a daily, so I don't let the same fuel sit longer than a week.

 

[Cpd419]

I on the other hand run 80-85% ethanol, aka e85 in this bike. Dropped my temps by 20-30*f , but then again I use this bike as a daily, so I don't let the same fuel sit longer than a week.

That is interesting. How does it affect your mileage? I run 87 octane whatever as long as it’s not sitting. When I winterize my engines I run straight gas or treat it with startron. No problems thus far.

 

[DJ427]

I on the other hand run 80-85% ethanol, aka e85 in this bike. Dropped my temps by 20-30*f , but then again I use this bike as a daily, so I don't let the same fuel sit longer than a week.

So its 85% ethanol and 15% gasoline? Keep us updated on how that works out, I would be curious to know. Thanks

 

[m in sc]

you don't need zero ethanol fuel for anything, I run 50+ year old bikes and cars on pump gas with zero issues regularly, most are hot rodded to some degree... for well over 15 years. I have -never- had an ethanol related problem, ever. I currently have 13 vehicles on the road, and all of them but 3 are carbureted (modern suv, the trail and my cb1100 are FI), most are air cooled. on a fuel injected bike its even less important. Water in the fuel, from shitty tanks in the ground is another story.

 

[ShieldArc]

In the owners manual it say's you can use up to 10% ethanol, more than that will void the warranty.