HELP RX1 cold start issues

[Al Bundy]

If my sled hasn't been used for a few weeks I blow a couple times into the gas tank vent line to create pressure, hold my thumb over the end of the line and turn it over. Seems that carbs lose their prime after a while. I asked about mileage because the previous owner of my sled had the valves adjusted @ about 12k miles due to hard starting...

 

[Loggerhenry]

I have plenty of fuel. Unhooked the lines off of the pump to a catch can and steady fuel. Also pulled the plugs and set them on top of the motor and bumped the motor and had a sharp blue spark. Pounding my head on the wall at this point.

 

[Al Bundy]

https://ty4stroke.com/threads/first-valve-adjustment.140343/

Dexter was the previous owner of my warrior.

 

[Neil Ryan]

Well it sounds to me your issue is electrical especially if you have lots of fuel. So chances are its related to weak spark and if I were a betting man I would say it's your pickup coil that is on the way out (even if resistance is good). My sled, 2005 RS Venture, went from hero to zero and having done the same trouble shooting as noted I replaced the pickup coil in summer. As soon as cold weather hit...same issue...Caution: I bought new stator and pickup coil and after installing the damn thing all I got was nininininininin and nada. I pulled the damn wiring harness out went over every wire and connector with a fine tooth comb. Then it hit me..what if the pickup coil leads from aftermarket pickup coil are swapped. So I removed the wire leads from the connector ( used a brad nail ) and swapped. The Sled started immediately and like you having cleaned carbs about 8 times has never run so good.

 

[Loggerhenry]

Just got back from my local Yamaha dealer and was told that since I pulled all the jets and air screws out that the carbs need to be sync back together. The carbs were never seperated. Before I removed the air screws I marked where they were and screwed them in till lightly seated which were all 2 turns out. Tested the spark which is excellent.

 

[Loggerhenry]

Back in the shop. I noticed that my choke plungers are leaking fuel. Got 4 kits on order.

 

[Al Bundy]

Back in the shop. I noticed that my choke plungers are leaking fuel. Got 4 kits on order.

Tell us how you make out; if you find the gremlins.

 

[Loggerhenry]

So I managed to get to the shop today finally with my new choke plunger assemblies. Been a busy month so far. Got them in and not much different on starting. A little better but it is 33 out now. I did notice after it started and warmed up that I had to back out the idle screw to lower the rpms. It was at 2500 or so and I turned the screw out 1/2 turn and dropped to 1000. Curious if it might be the tps sensor or still an accumulation of things.

 

[Fortress]

Both mine are like that if they sit over a week, the gas drains back, if it cranks too long I squirt gas in carb

 

[Loggerhenry]

So back at the shop. Bought an ultra sonic cleaner on ebay. Double checked and made sure that every port and orifice was clean. New fuel pumps, coils, needle and seats, tps sensor, and all new pilot screws. Primed up the carbs and fuel lines with a squirt can. Fired it up. Started up better. Had a high idle. Kept backing out the idle screw on the rack all the way but still had a high idle. Got to looking at my throttle cable up on the bars. The cable was not secured with that metal tang so it was just sitting in there. Fixed that. Idled down to where its supposed to be. Came back a few hours later after it cooled down so I could do a cold start and warm up. Full choke and started. Got it to run high idle with half choke, which its never done before. Last thing I will probably do is send it to the shop to sync the carbs.

 

[jameshofo]

So back at the shop. Bought an ultra sonic cleaner on ebay. Double checked and made sure that every port and orifice was clean. New fuel pumps, coils, needle and seats, tps sensor, and all new pilot screws. Primed up the carbs and fuel lines with a squirt can. Fired it up. Started up better. Had a high idle. Kept backing out the idle screw on the rack all the way but still had a high idle. Got to looking at my throttle cable up on the bars. The cable was not secured with that metal tang so it was just sitting in there. Fixed that. Idled down to where its supposed to be. Came back a few hours later after it cooled down so I could do a cold start and warm up. Full choke and started. Got it to run high idle with half choke, which its never done before. Last thing I will probably do is send it to the shop to sync the carbs.

When you clean the carbs you need to verify that you can see through the pilot jets. I've had tons of trouble with this myself, and I have a Sonic Cleaner big enough to put the entire carb rack in. I've taken to just buying a spare set of pilot jets. When I clean the carbs I install the spares in and put the set that was in the sled into a solvent bath. If you know the pilot jets are clean try backing the fuel screws out 1/2 turn, I'm willing to bet that will fix it. I doubt this issue is a result of carb sync if you haven't messed with it, unless its also backfiring.

For ballbuster, I'd try jumping it off a car or something when cold its that cold to test. If it starts much easier your battery is likely the issue. Also if your oil is not a 0w30 or 0w40 that may be contributing to your hard starting issues. These motors are very reliant on a fast crank speed for effective starting. You could also try dumping a bottle of heat into the tank in case the issue is a little water in the fuel.