RX1 Warm Starting Problem

[cadiyama]

My 03 RX1 gave me fits last year when it came to starting it once it was warm. Cold starting was no problem. It ran fine once started. I tried several things such as giving it gas when cranking, no gas, choking it etc.
Nothing really seemed to help. It almost acted as if it loaded up with gas just sitting not running. The group would make a trailside stop and I would have a heck of a time restarting. The only thing that seemed to help at all was to crank on it for a good long time then crack the throttle slightly. Any ideas guys. Dirty carbs? Out of sinc carbs? The plugs were all changed.

 

[suprfst]

Was it pretty warm out?

I ran into a smillar problem when its warm out the coolant that heats the carbs would heat the fuel up and it would start but run horrible for 5 to 20 seconds then clear up,only when its warm 40+ degrees.Put a valve in the coolant line to shut it off no more problems.

Any other time when its warm I have to crack the throttle a little.

 

[BlgsRX-1mtn]

Do you have a carb coolant shut off installed? My '03 RX-1 mtn did the same until I installed a shut off valve. The heat from the coolant causes the fuel to boil in the carbs causing a vapor lock. You can see the red handle on mine in this picture. It is located on the small coolant line going to the top of the carbs near the fuel pump. I used a 3/8" brass ball valve from Ace Hardware with male nipples to fit the line.

Jim

 

[yamrx1]

Common problem when it is warmer temps. coolant shut off for your carbs is in order..

 

[Len Todd]

I have never experienced this even on a 50 Degree day and I do not have a valve. I do flip the carb flap off the carbs when it is over 20 Degrees F.

I am wondering if a (or several) Carb's Float could be hanging up. When your sled acts up, have you checked to see if the plugs are wet or dry? If they are dry, then maybe you have a vapor lock. If they are wet, then I would take a look into the carbs.

 

[cadiyama]

Coolant shutoff valve

Thanks guys, I think that may be it. Sounds logical anyway and not too pricey of a fix. Will most any shutoff valve work that will fit in the line?
Is there a certain temp that you shut it off at?

 

[cadiyama]

Carb flap

I'll try flipping that flap off the carbs also, it may be getting too hot on warmer days.
The plugs appeared dry so I think the floats are ok. But if the coolant shutoff valve doesn't work I'll check the floats.

Thanks
Randy

 

[Sled Dog]

You could just try pinching the line on one ride to see if it fixes the problem first.

 

[4bangdan]

You could just try pinching the line on one ride to see if it fixes the problem first.

good idea!

 

[Grunter]

check this out!

Make sure your vent lines go downwards - without any droops in it as so to lock fuel in the lines! This will cause the machine to do exactly what you are describing! Placement of these lines are critical!

If there are droops it will start perfect cold - but sputter and when trying to start(if start at all at times)

Let me know if this helps ya!