Hello all, I surely hope that somebody here can help me because I'm at my wicks end with this problem. I have a 2000 Magnum 325 2x4 that has been sitting for about a year(axle was broke but fixed now). Before it was stored, I had problems with it not accellerating to full speed and sometimes it would start bogging when it was running wide open. Now that I have fixed the axle, I am having worse problems with some sort of carb issue! I took the carb off and cleaned it really good and drained all gas from the tank and replaced it with new. When I first started it, it idled way too high(so high you couldnt put in in gear) and adjusting the idle screw did not change anything. I adjusted the cable adjustment that was near the actual thumb throttle and the idle fell to an acceptable level. However, when I actually tried it out yesterday, the idle had come back up so i adjusted it again but could find no happy medium, it was either too high or so low that it would not continue running. I also noticed that during acceleration, it would bog and take a second to actually take the gas. It also would backfire when I left off the throttle. Any help is greatly appreciated with this issue!

 

Sounds like you still have varnish in the carb causing things to hang up. If you have high idle I would blame that on a lean condition. Bogging at high speed usually is a shortage of fuel which also points to the carb.

You might have a float that has gone bad and is saturated and drops down and closes the needle and seat. If it were mine, I would pull the carb again and buy a new needle and seat. Also need to find the idle circuit screw, remove it and look for gum on the end of it. You will need specs as to how many turns out from stop it is in order to get the adjustment correct. Be sure to count the turns when removing is also another way to go.

These little engines vibrate quite a bit and with it being 10 years old and the fuel issues we now have, I would bet that the carb has those issues as a result of bad fuel. If you can find someone who can soak it in carb cleaner to insure it is clean then start over with some new parts you should be fine.

You will need to know if there is any plastic parts in the carb that could be damaged by the carb cleaner so a call to a dealer may be a good idea before you soak it for any length of time.

 

Pilot jet is stopped up

 

You are probably right. I referred to the idle circuit screw but I really meant the air screw. Hopefully he will respond with what he finds.

 

I havent had time to take the carb back off yet but I have done some more troubleshooting. When I spray starting fluid on the carb boot, the motor revs slightly, which is odd to me because I thought it would bog it out. I tried it several times to ensure that is was not a coincidence and it did it every single time. I even tried carb cleaner and it did the same thing! This ones kinda got me stumped......

 

You may have a cracked carb boot and when you add fuel in the form of carb spray it is like addding throttle and more fuel, hence the rise in rpm's.

You need to get the carb off and pull the boot as well and inspect it carefully as it will cause a lean condition and you will be buying a piston and other parts if it is not looked after.

As we stated before, you need to look at the carb again as your issues most likely are inside the carb and not just related to the carb boot. However, inspect the carb boot for cracks and if it has some, replace it and then see how it runs. If no change go back to the carb. Nice to do one thing at a time so you can isolate the issue. Keep us informed please.

 

Ok, I took the carb off again and cleaned it good again. I used blue RTV silicone and sealed between the carb boot and the block. This seems to have fixed the carb problems. However, it is still sluggish on acceleration but I believe this is going to be a drivetrain issue. I have a new belt on it that probably has only 2 hours on it. Im thinking that it may be the clutch buttons. What I'm wondering now is whether it will be the front or rear clutch? I see on the part schematic that the front has clutch buttons and the rear has clutch ramps, which one would cause this problem? Thanks guys!

 

You will have weights and rollers in the front clutch and buttons in the rear unless it is a roller/team clutch.

Sounds like it is not shifting out all of the way.

However, the RTV silicon on the carb boot may not have cured everything. Did you bend and inspect the boot thoroughly as they tend to have cracks in them that you cannot see until you bend then around. It could still be sucking air and leaning things out so make sure that is looked after. You can spray carb cleaner on the boot when running and see if there is a change in the rpms. If it does not change then you have that problem resolved. The previous poster talked of a dirty pilot jet. Did you remove it and clean the orfice as well as the jet?

All the little things add up.

How many miles on the machine?

 

Hello All.
I have a 1997 Polaris 400 Xpress. I have rebuilt everything on the engine and now I am to the Carburetor. My question is: Does anyone know exactly how to adjust the throttle cable and choke that is located on the carb. (2 adjustment screws)? I can get my ATV to turn over but it won't start or idle...It cranks and sounds like it wants to start but it doesn't...Please help me...

 

Hope my pm helps. OPT