Air-Cooled XR's?

[XR400RMan]

I have a 1991 XR250R and the SUMMER is coming and I haven't had the bike in the hot summer before, Here it gets about 90 to 95 degrees F,and the Humidity is almost at 100% so how easy will my XR250R overheat on fast fire roads and tight trails? Thanks Matt

 

[dave186]

I had an 87 XR600, and i rode it in 100 degree weather and i dont know if it was overheating or not but it ran good once ya got it started. I did have an aftermarket oil cooler on it though.

 

[snaggleXR4]

Hey,
Overheating is a relative term. In the case of liquid cooled bikes, they will boil the coolant out. In the case of an aircooled bike, nothing happens, until you literally burn up the piston and/or warp the cylinder head. I've had several aircooled XR's here in Florida, they run really hot, but that's about it. Never did have a problem. Keeping fresh oil in your motor all the time is one of the best ways to keep an aircooled bike in good shape. Good luck.

 

[EM rider]

I've put many miles on my XR in the SoCal desert and Baja where temps regularly exceed 100 and have never had any problems. As mentioned, just be sure and keep the oil fresh and don't let the bike idle. I always kill the engine whenever I stop, even if only for 30 seconds.

 

[mtngoat]

The valve stem seals on one of my XR4s ( a "buddy bike") got fried. I'm pretty certain it was the result of letting the bike idle in hot temps. I know the XRs run high head temps; probably too high without air movement. Other than that, the XRs seem pretty robust at high riding temps.

 

[XR400RMan]

Thanks for the replies everyone, Hey SnaggleXR4 will I know thats its getting ready to burn my piston and warp the cylinder? will there be a great loss in power? I will probably just try and stay off of the tight trails and just on the fire roads which are fun anyway and that way I will be running between 40-50MPH most of the time. Thanks again Matt

 

[Hondaman_06]

really i think everyone has pretty well covered this. the worst thing you can do is let it idle that will heat the engine up faster than anything. Always keep moving and try not to putt around to much. Just as a precaution i'd take a break ever once and a while and let it cool down a little bit this coudln't hurt either.

 

[helterskelter400]

in the oz scrub ridin tracks that used to be used (40deg deep quartzy sand with wiry spikey shrubs & trees in 2nd & 3rd) the bike heats up, just stop for a drink & light ur ciggie up on the headers.

only oheat problem i had was with the old 85xr250. since redesign in 86 (incl oil cooler & more oil capacity), no probs.

change oil freq tho. this holds true for any revvin machine tho.

enjoy

 

[DualSportr]

Good oil, change it VERY frequently. This will absolutely be the difference between a healthy engine and a dead one.

Oil changes after a weekend's worth (15-20 hrs) of riding would be appropriate.

Make sure you use a GOOD oil, cheap oil will break down more quickly.

 

[XR400RMan]

Thanks for the reply Dualsportr, Did you get my updated information on my XR that is burning oil? Go to the "HEAD PIPES,1 HOT,1 COLD" thread and go down till you see where I updated it, Matt

 

[191028]

I can't remember who makes it right now but there is a temperature gage that replaces the oil filler cap that works very well. I have one on my xr400 which I use to watch my oil temp in the hot summers in AZ.

 

[XR400RMan]

Thanks for the reply 191028,

 

[KWJams]

Air Flow is the key

If you are not getting a good air flow to cool the motor then it will get hot.
Even 120 degree air will cool the motor as long as the fins can radiate off the accumulated heat.
Getting too hot is not that big of a problem as long as it is within reason and you cool it down gradually.

Avoid extend time riding in real tight terrain, idleing and lugging the motor.

Watch out for mud plugging up the cooling fins, this will create hot spots which will stick a piston.

 

[Jh85]

temperature gage that replaces the oil filler cap

:D

 

[detaildon]

xr's onlt makes the temp gauge/oil cap. you can purchase it from bajadesigns.com