GP1200r - Impossible to start if left sitting for a week.

[gp1200r_rider]

Hi everyone! This is my first post and its a bit lengthy so my apologies. Hope all are doing well here. This looks like a great place with a lot of knowledgeable members.

A friend and I both have GP1200r skis. These bad boys run great, when we can get them started. I'd rather not go to the shop and spend 500 bucks so I'm trying to diagnose on my own. I know how to turn a wrench so not a problem in the self help department if I have a service manual.

Anyway, both of these skis are very, very hard to start if they sit for a week. Both have 120-ish hours on them. Starting either of them generally requires jumper cables after grinding away until the battery gets low. Once started, they fire instantly thereafter, so it really seems like a fuel delivery problem. We've changed plugs, fuel, added fuel system cleaner, changed fuel filter but no luck, replaced oil lines, checked sensors, etc. I haven't checked to see if it's getting spark yet. Was too mad to screw with it anymore this past weekend.

I have no idea what was done to them prior to my ownership since both were bought used. They ran great last year. I do see that the cat sensor connector has been replaced with resistor plug so apparently they have a D plate too.

I've read of issues with the accelerator pump on these. Could this be the problem? I found a copy of the service manual but have a few questions....

What is the % probability that the acc pump/s is the culprit? Do I need to replace the accelerator pump/s (is there only one or one per carb?) or can they be repaired?

Where are these pumps located? Directly on the carb/s? How difficult is it to get full access to the carbs/intake? I see the exhaust sits above the carbs. Looks to be an all day process to get it out of the way.

I've heard they eat power valves which makes schrapnel out of a piston and have read of Waveater clips. I assume I can't install those either unless I remove the exhaust, etc.

What electrical/sensor type situations would be occuring that would prevent it from firing?

What should I do to these to ensure another 120 hours of reliability?

Thanks for all your help!

Eric

[cwehner]

My 2001 gpr does the same thing only now when it heats up (hour or so of usage) I have trouble starting it... seems to be flooded. I have to choke it to start and somethings I have to keep choke on a little to run. It runs great when started, 62+ mph... It has not had a carb rebuild so???

I would love some advice?? Hate to take it in and get a $500 bill as well for something that didn't require it.

Chris

[Jeff Walkowiak]

if you replace all the diaphragms and clean all the internal filters you will usually solve that issue,,, the fuel is draining back to the tank and it is taking a lot to pump it back to the carbs to get it going,, some people use primer kits but that really isn't fixing the real issue it is just solving part of the problem,, you could simply pour a bit of premix fuel in the carbs to get it to run initially or place a primer ball in the fuel line like outboard engines do,, but the real solution is to rebuild he carbs and fuel pump.