cold starting/running. really cold

The WR400 will be my primary winter ride in here Chicago. While those in MN etc. scoff at Chicago temps, still I anticipate starting the bike at well below freezing more often than not. The bike sits OUTSIDE, no pansy-ass garage to sit in. *duck* So is 10w oil going to be sufficient? I have to go read the label as to viscosity at those temps. how much fun will I have kicking the thing over anybody reckon?

I have a 98 wr400 and ride alot in the extreme cold- could pack that sucker in ice and it would fire on the 3rd kick

10W should support -10°C (14°F)

i was suggested to kick it a few times with decomp pulled so the pump spits some oil into the head (this goes for the longer term of no riding, week or more)

mine defenately doesnt like the cold, even when it cools down in cold weather 1 hour after ride i have problems starting it..never tried with a few twists of throtle though

bike is all the time stored in a coasy garage, spoiled

You may want to go lighter then 10W. You are just on the bottom end of the temp. scale, depending on how cold you are talking. We get -30 celsius and colder here. Check out your manual and if you don't have one just go online and download it.

yamaha makes a cold weather formula oil. I used it last year. No troubles.

Dont forget to rejet also. At the minimum put in a larger starter jet. My yz400 has a 65 stock. I put in a 72 in the winter.

If your bike starts and stalls about 20x while you are trying to start it cold it is the starter jet causing that. Go bigger and it will start sooo much better.

It'd be a good idea to block one of the radiators so it gets up to full temp....

You might want 5W for the winter.

I tried starting my '02 426 last week here in Detroit. It was only 45 degrees and I almost gave up starting it. I don't think I'll be doing much winter riding this year!!! Fat jets and I still almost kicked my leg off!

Winter here is 8 months, I ride year round and my WR sits outside and starts fairly easily down to -30. Colder than that I usually use a heat gun to warm the rads for a few minutes. I use Polaris synthetic 0 W 40 in the crankcase and Polaris premix antifreeze rated to -52 in the rads.

There are a few tricks to extreme cold starting. Richen up the carb depending on temp. Before you kick, turn your idle screw up 1 to 2 turns depending on temp and choke on. Set up on TDC as usual and then squirt in some fuel with the AC pump. At minus 20 I usually give it 8 squirts, then place your right hand on the crossbar to avoid throttle input and then kick. Usually the first kick does nothing. Reset to TDC without touching the throttle and it'll fire on the 2nd kick. It'll just run for a few seconds until it burns up the extra AC fuel in the cylinder. Don't touch the throttle, let it idle until it quits and then restart the complete procedure until it builds enough heat to stay running by itself. When you shut down in cold weather, make sure you leave the engine at TDC. I've had condensation form and freeze on open valve stems after engine shutdown and had zero compression the next morning since they can't close properly. The only cure then is to heat to melting point to restore compression.

2 wheels north of 60

Arctic Traffic

nice!

just to add, TDC is when kick gets too hard to kick

always keep mine that way, because in long term, I believe its also easier on valve springs (a bit off topic)

Winter here is 8 months, I ride year round and my WR sits outside and starts fairly easily down to -30. Colder than that I usually use a heat gun to warm the rads for a few minutes. I use Polaris synthetic 0 W 40 in the crankcase and Polaris premix antifreeze rated to -52 in the rads.

There are a few tricks to extreme cold starting. Richen up the carb depending on temp. Before you kick, turn your idle screw up 1 to 2 turns depending on temp and choke on. Set up on TDC as usual and then squirt in some fuel with the AC pump. At minus 20 I usually give it 8 squirts, then place your right hand on the crossbar to avoid throttle input and then kick. Usually the first kick does nothing. Reset to TDC without touching the throttle and it'll fire on the 2nd kick. It'll just run for a few seconds until it burns up the extra AC fuel in the cylinder. Don't touch the throttle, let it idle until it quits and then restart the complete procedure until it builds enough heat to stay running by itself. When you shut down in cold weather, make sure you leave the engine at TDC. I've had condensation form and freeze on open valve stems after engine shutdown and had zero compression the next morning since they can't close properly. The only cure then is to heat to melting point to restore compression.

Dumb question. What's "AC"?

Dumb question. What's "AC"?

It's the accelerator pump on the carb. When you twist the throttle it gives an extra squirt of fuel into the engine.

AC=accelerator pump, it's connected to the throttle, and squirts fuel into the airflow.

nice!

just to add, TDC is when kick gets too hard to kick

always keep mine that way, because in long term, I believe its also easier on valve springs (a bit off topic)

Never thought of that, good point. :cry:

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