Cold Weather

[MikeyG]

Hey guys,
Iv'e got a problem here. Whenever I ride and the temp. is below 40 or so, the bike just WON'T heat up. Im afraid of doing damage so I stopped riding. I know plenty of people on this site that go winter riding, and want some tips. The bike is a '99 KX125, 5-30 in the trans., 160 main, 3rd clip needle, AS 1 3/4 turns out. The bike is running a BR9EV plug, mostly because thats what the manual says and Im afraid of switching without DRN consent :). Should I try a BR8 plug? Iv'e also heard of covering the 2nd radiator with cardboard. Is that safe?
Any Ideas? I NEED TO RIDE!

 

[Glitch]

I dont think covering a radiator is a good idea, I could be wrong though. Running a BR8 should be fine, I do it. But I wouldnt recommend running WOT with this plug, might heat up engine too much.

 

[James]

Are those the same jets you use when the temp is 70 degrees?

 

[bedell99]

I ran leaner jets,155 main, 2nd clip on the needle and a leaner pilot I think it was a 42. I also ran a number 8 plug. I had absolutley no problem with the bike heating up.

Erik

 

[MikeyG]

Originally posted by James
Are those the same jets you use when the temp is 70 degrees?

Yes the jets are the same. Now I know that is a huge No-No but I have a incompetant dealer who can't seem to get me jets for a decent price (less than $20 for one main jet would be nice). The jets are a bit rich in the summer, and the plug is a light tan in the winter so I think its fine. I lower the clip and turn in the AS, but thats about it in the winter. Any other ideas?

 

[SuzookKING]

When I am roadracing a 2-stroke gp bike, I duct (redneck version=duck)tape part of the radiator(s) to try and keep heat in the motor when running in cold/cooler weather, hopefully preventing a cold seizure (in 2 to 4 hour endurance events even). I eventually went and bought a bypass type of thermostat they use in karting to keep the engine temps around 138-140*F. I get quicker warm-ups and it stays there quite nicely and I don't have gooey remnants of adhesive to deal with anymore. The principle should work as well for off-road riding I would presume (NOT assume).

 

[viking20]

A while back someone suggested using a KTM thermostat for the right side radiator.Anyone tryed this?Im wondring if I simply install it in the hose,and what KTM model uses it std.....

 

[WoodsRider]

How do you know you're bike isn't heating up?

In cold weather it will take longer for the bike to reach normal operating temperature, so you have to idle it longer before you start riding.

The method I use is to start the bike and let it idle until both radiator top tanks are warm to the touch of an ungloved hand. Since the bike is not moving no air is passing through the radiator so very little heat is being given off by convection. Once you start moving the colder air will allow the coolant to reach a lower temperature as it passes through the radiator.

You need to jet the bike according to the ambient conditions. Do a search or post in CR,KX, RM, YZ forum to get some ball park specs. If you're dealer is bending you over on jets, go to another dealer that sells jets for your carb, Keihn I believe. In my experience if the dealer needs to know the type of bike you own, they don't know squat about jetting and will usually hose the customer. If you tell them you want a 158 Keihn main jet and they can reach in a bin and grab the right jet they are your source for jets. ;)

 

[jet373]

20bucks for a main jet ,,,,, dudes ripping you off and make pocket fat too .... retail on a main jet is about 5 bucks pliots should about 7 and needles 10 to 15 bucks

 

[SuzookKING]

If you choose to go the thermostat route I would stay away from the types that block off all coolant flow until they open (circulation blocker style). The ones used in karting allow coolant to flow through the cylinder and head until it reaches temp, then it allows the coolant into the radiator/radiators (bypass style).

If it's COLD outside, even when you extend the warm up time, you have the possibility of having a cold seizure from excess cooling once you are underway.

 

[dthoms]

Living in Michigan I run into the same problem. I usually drop the clip, to raise the needle and that usually does it. I have never blocked the radiator, or put in a theromstat. However I don't ride when it gets real cold. I just fired up my 95 RMX and rode it around the woods a few times, and I'm sure before I go riding this next week I'm going have to adjust the jetting a little.
You also mentioned something about the plug, I'v always had the best luck with the B8ES. The cheaper ones seem not to foul out as easy, and there cheaper. I have a 02 KTM 250 EXC but it didn't want to fire, which doesn't suprise me. It still has the original plug and is jetted a little leaner than the RMX to begin with.I'd rather ride the RMX in the snow and ice anyway and save the EXC for the better weather. I am mostly a fair weather rider but after a while the bug bits too hard for me to restist.
What kind of tires are you running ?
I have some dunlops 752 rear 755 front with cold cutter scews in them.
I would like to try some trellborgs but it seems a little pricy.

 

[Luft]

Mikey G: what oil and ratio are you running? Is the humidity high with snow and rainfall or is the air dry? Find another dealer, AS and MJ are $5.00/each. There have been some good posts about carbparts.com on this board. If the air is dry (less humidity) stock jetting should be in the ball park but if it is damp and humid this can throw everything off. How does the engine pull off the bottom? What color is your present plug?

 

[MikeyG]

The jetting is a little lean on the main, but thats it. Im runnin Mobil 1 MX2T at 32:1 and Mobil1 0w-40 in the trans. I don't have a lathe so I cant check the plug, but I can feel the "leanness" on the main. I don't think the problem is in jetting though. The damn engine just won't reach operating temp. Im worried about using an 8 plug in case I blow the engine. Im low on funds.