johnny7

Sorry guys thats a 1998 xc700

I have a problem keeping fuel at the carbs once the machine sits for an hour or more. I just pulled it out to clean her up and I tried to start it but no luck, Took off fuel line at the carb and completely empty. Pulled some more and still mothing there. Would installing a primer inline solve the problem. I could pump up the fuel after every time it sits like i do with my outboard. choking makes no difference. Had a problem starting last time i was out. Took 4 of us pulling on it before it would start.

once running machine performes like a champ. Wicked mid range will almost pull your knuckles out at the joint. 120mph easy. New pistons and rings last 80 miles used.

Thanks guys

BC_Dan

Welcome to the forum!

Is there fuel in the float bowls after it sits? Or is your problem no fuel going to the carbs from the fuel pump?

One thing that could cause hard starting after sitting would be a hole in the fuel pump diaphram. The hole will allow fuel to drain into the crankcase through the diaphram via the crankcase to fuel pump impulse line. You can check that pretty easy; pull the line off of the crankcase; if it's got fuel in it, or is dripping with fuel from the fuel pump, your diaphram has a hole.

Hard starting could also be caused by carb inlet needle/seats leaking, overflowing fuel into the carbs and into the crankcase. You have to crank the engine over a bunch to get rid of the excessive fuel. There are small plugs under the exhaust pipe that you can remove to drain excess fuel from the crank. You can remove the plugs to check for fuel; if you get a bunch of fuel out, you know you are dumping fuel into the crankcase from somewhere. Draining should help with starting, but you will still need to figure out where the fuel is coming from in the first place.

Do you shut the fuel off to the carbs when it sits? If that helps, it could be the carb needles. If it doesn't help, it could be the fuel pump diaphram.

Good luck!!

__________________
2007 RMK 700 155", 2008 RMK 600 155", 2006 RMK 600 144", 98 Indy 440, 95 Prowler 550 2-up, 1990 Indy 650

RIP, destroyed by fire 1-22-2008
04 RMK 800, 05 RMK 600, 02 RMK 800, 97 RMK 700

http://www.avalanche.org/accidents.php

johnny7

Thanks dan.

Thats the first time i got a good answer from anyone. I always shut the fuel valve off when i park it. I will get it up and running and then check the pulse line from the crankcase and also the crank case itself.

Thanks so much

john

BC_Dan

If the fuel is shut off, it almost has to be the fuel pump. Kits should be available for rebuilding. If you are considering buying a new pump and yours is like the 1997 where the oil goes into the fuel pump instead of into the carb, have someone stand by with a defibrillator when you check the price! Polaris wants about $94 bucks for the dang thing! Makes rebuild kits look more and more attractive!

__________________
2007 RMK 700 155", 2008 RMK 600 155", 2006 RMK 600 144", 98 Indy 440, 95 Prowler 550 2-up, 1990 Indy 650

RIP, destroyed by fire 1-22-2008
04 RMK 800, 05 RMK 600, 02 RMK 800, 97 RMK 700

http://www.avalanche.org/accidents.php

white lightning

I agree with BC - I had that symtom with a friend son's sled when he brought it to me to fix it for him. As it turns out, when I got it running, it wasnt running quite right and I found the problem that the excess fuel was going into the crank. Once I switch the fuel pump with another one, the sled ran much much better afterwards. WL

johnny7

BC Dan / Whitelightening

Thanks for the info so far guys. I started up the sled on Wed for the first time. Filled the fuel line and one pull and she started. Next day same thing one pull and started bang. Then I let it sit for two days and today took 5 pulls. Used 1/2 choke, kicked on third pull then took two more.

NO fuel in the crank at all, not a drop, no fuel in the pulse line either.

I,ll wait two more days then check everything including the fuel line and see if the fuel has disappeared or shows up in the crank or pluse line.

Thanks john

johnny7

Well Dan
I waited two days and pulled the crank plugs out and I had about a table spoon of fuel come out of each cylinder. The fuel was shut off.

I would think that it is the fuel between the shut off valve and the carbs. That would explain the hard starting as the line is empty.

Next question how hard is it to replace the needle and seats????

Thanks
john

BC_Dan

I never took 'em out of my Keihin's, but they should be pretty simple... it's a maintenance item and those carbs are not complicated. Finding new ones may be a problem, though.. not many snowmobile places sell Keihin parts...

__________________
2007 RMK 700 155", 2008 RMK 600 155", 2006 RMK 600 144", 98 Indy 440, 95 Prowler 550 2-up, 1990 Indy 650

RIP, destroyed by fire 1-22-2008
04 RMK 800, 05 RMK 600, 02 RMK 800, 97 RMK 700

http://www.avalanche.org/accidents.php

white lightning

For Keihin parts, you should be able to get them from any Polaris dealers. keep us posted - WL