TXC450 (and other 4 strokes) opperating temps

don't know what the temps were on my 510 but what I do know is that it ran pretty dang good on very little coolant after boiling over and ran right up until it got so hot it cooked a stator. No flubbering, sputtering or hiccup right up until it just cooked on a lap. Put new stator in and fresh oil and it fires right up and has same great compression. I am needing a computer for my TXC, might just do the trail tech myself to see what the temps are. I have installed a stiffer rad cap from a KX85, this should increase the boiling temp and prevent future boil over by a few degrees.

So what was the temp? I was stuck in a bad traffic jam the other day, and my bike got real hot. Cooled off fine when I was moving, but I was curious just how hot it was. I am thinking about some sort of temp gauge myself.

Uptite Y was installed before the bike was even heat cycled once, then installed the new super duper cross-over link after a few heat cycles (fancy talk for it didn't make it to the break-in service as I was hoping it would when I didn't have the proper size hose during the prep) So I had to change coolant twice before the break-in. Anyhow, I did have MSz rad gaurds on during the 24hr enduro and will experiment with and with out as I have a very trick laser temp tool that I love to have an excuse to actually use. I think the fact that the TXC's actually have an overflow can as a big plus over my KTM 525's, they boil over and now when it does start to cool back down the KTM without resevoir can't reclaim coolant like the Husky's

The answer to the question is that 4 strokes, the Husky included want to run below 160 f. Above and you will have problems.

Ambient (outside) temp plays a big role in this. On cool winter days with temps in the 40's and 50's you can ride for days with no coolant.

As pointed out the first thing to fail is going to be the stator. This is a good thing. Means you wont loose a piston or rings when riding at severe overheating, the bike just dies.

Engine heat can be controled with numerous changes, but easiest of all is to not use the clutch as much. The clutch generates heat, big time.

Installing a fan is also a great way to go, but there are many other things to do to lower the heat.

I use oversize radiators, dont block the air flow to them, run an open pipe, run a cooler plug, run slightly rich jetting, use Evans in the radiators, a Y, and ive installed a fan. Might even be worth installing two fans.

Just ideas.

Anyway--ive been using both temp strips and a TT temp guage/computer for a couple years on my 510's and the magic temp limit is about 160-165.

Where did you mount your temp strips? Thanks, TW

Okay, I read about the Y-pipe, but what is the "reinforce crossover tube" you refer to? The '08 comes with what appears to be a 120mm computer fan already installed on the upper section of the right radiator (which would appear to be the side that flows less due to the T-pipe instead of the Y-pipe). That flow "correction" is on my shortlist.

Mike, that temp seems a bit low to me for efficient combustion. Aren't most thermostats set at about 190 deg F?

I run Evans NPG-R, with George's Y, and typically see between 160-180 rarely momentary 200 water temps. I run temp strips on the cylinder head (just below the 'Husqvarna', can't see it while riding), one on the water pump and one on the top of the clutch cover. I frequently check the water temp while riding. I don't clutch much so it rarely exceeds the water temp. I've never felt any hot symptoms while riding, no pre-ignition or loss of power, and never boiled any coolant, Evan's boils at ~400 deg F and it expands very little and thus runs very low pressure.

Roughly the same temps here although I will once in a while go over 200 if its hot out and I'm crawling up steep single track, I put a 185 degree temp switch for the fan at the bottom of the radiator so really my fan does not even turn on until the water temp returning to the motor is above that.

The best ive ever seen a Husky run at was right around 160-165 down in Baja. In fact 165 was as high as it got all day. Stickers on the motor, and an in-hose temp guage. IMO this is the temp to shoot for. As it gets hotter, it makes less hp.

110 race fuel, custom made ''restricted'' Y, Evans, spot on jetting, opened up air box and pipe, basic race bike. TC 510.

Wish I had of read this a few months ago. Bike was boiling a bit all day and blew the crossover tube. Must wire the fan to operate all the time as well.