4 stroke hard to start in the cold

S

skibum_1260

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Dec 17, 2007

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• Jan 24, 2011

• #1

Anyone have any tips for starting a four stroke in the cold? bike is a 05 crf450x 2 moto kit, have tried jetting rich and lean, couple pumps of the throttle, no throttle, elec start, kick start about everything i can think of and still usually takes about 10-20min of kicking to get it going if its been outside over night or for a couple hours. But once started it will start first kick no problem, or if its in a heated shop again first kick.
Thought about some sort of block heater if its outside overnight but its hard trying to find one that will fit somewhere in there.

 

4

440dart

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Jan 5, 2008

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montana

• Jan 24, 2011

• #2

check your valve clearence

 

J&L Snowhawk

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stores.ebay.com

• Jan 24, 2011

• #3

not valves im sure

if it starts that good warm it is not the valves. should check the clearance anyways for good service. our 450 honda starts hard to cold but seems to work best if you pump the throttle 5 times then kick some then repeat. It is like a primer with the accelerator pump.
They do make a glue on block heater that you could put on the bottom of the engine possible.

 

S

skibum_1260

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• Jan 24, 2011

• #4

yeah its not valves, there good, tried the accel pump before but then it seems to almost make it worse,
found a glue on heater im going to try on the bottom of the case and see how that goes.

 

T

triedit

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• Jan 24, 2011

• #5

hard starting

change oil to a synthetic

 

R

relentless rider

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Jan 25, 2009

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in the mountians western mt

• Jan 24, 2011

• #6

Pump the throttle 3 times kick over a few times,pump the throttle 3 more times,slowly kick the motor over tell the piston comes to the top than kick it hard,it worked every time on my 06 crf450 in the cold.Give it a try.

 

P

prerunnerinidaho

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priest lake idaho

• Jan 24, 2011

• #7

My KTM 520 is the same way when its cold. I have found that kicking it through with the comp release a few times then 2 blips of throttle and kicked hard from the top will lite it off every time. unless ive got all my gear on then its a steamed up fight.

 

J

Jon Mutiger

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• Jan 25, 2011

• #8

I'm running Maxima MX530 oil, and its definately helped me with starting it on the cold mornings.

Outside of that.. Make sure your coolant isn't freezing, alot of the summer coolants have very little freeze protection, and your water pump pushing the gelled goo around could be slowing things down.

Make sure your gas isn't freezing too, some gas line antifreeze will help in that dept.

Kick harder!

Jon

 

T

TeamOrange

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Nov 24, 2010

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• Jan 25, 2011

• #9

Make sure your getting a good hot spark too. Are you using race gas? Too high octane might not burn as well.....just a guess there though. Might check for ice/water in float bowl. maybe a shot of raw fuel in the plug hole would answer a fuel related problem.
Just some thoughts I had.
Good luck

Oz

 

D

Dobber1

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Nov 26, 2007

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• Jan 25, 2011

• #10

Here's what works on our '04 250X...

5 full twists of throttle, slowly depress kick starter until you hear comp release "click", then give it a full kick from the top, repeat this step until it starts.

 

J

jethro450

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Dec 27, 2010

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• Feb 1, 2011

• #11

I've had an 06 and now have an 08 450f. I have the explorer kit though (stock airbox) so maybe the different airbox affects things.

But I run regular ol Honda 4-stroke oil per manual.

Put piston at tdc BEFORE pumping throttle.

Pump throttle five times.

Kick hard.

It starts first kick every time. Even in subzero temps. Sometimes it will die shortly there after cause the oil is still thick, but it usually starts right back up and I leave the choke on for a while tell she's warm.

My jetting is lean. 3rd clip on the needle. 160 main. I think I have a stock 42 pilot though, might be 40 (can't remember). I ride at 9k-10k elevations. There are other forums on lean jetting, but in a nutshell, Honda puts out a manual with super super rich settings. You'll know if it's too lean!

Anyways, perfectly set valves are always a plus as well. I'm not sure if I agree that just cause it starts easy when warm that the valves are good. I've noticed that even .001" out of spec makes a big difference when starting cold. My brother had a 250F that sounds just like your bike. The hard starting first began only when it was cold, but then it progressed to being hard to start all the time. It was the valves.

Good luck.

 

R

retired motoman

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Priest Lake

• Feb 6, 2011

• #12

Second on the syn oil

Jon Mutiger said:

I'm running Maxima MX530 oil, and its definately helped me with starting it on the cold mornings.

Outside of that.. Make sure your coolant isn't freezing, alot of the summer coolants have very little freeze protection, and your water pump pushing the gelled goo around could be slowing things down.

Make sure your gas isn't freezing too, some gas line antifreeze will help in that dept.

Kick harder!

Jon

Click to expand...

Try a lighter oil too. I use 5/30 in the trany and 15/50 in the engine.