New to the forum. thanks for letting me join! I have a 97 magnum 425 4x4 I just recently purchased. When I bought the fourwheeler it ran great for the most part, but when I got it home the carb was flooding. it would run but wouldn't idle and would have dead spots, run smooth then have dead spots. I went through the carb, changed the oil, and plug and threw a new air filter on it. after all this it started running at a high idle with no throttle response. it was also spitting fuel back through to the filter housing, so I purchased a brand new carb and the same thing was happening. a high idle that I could not get to go down unless I choked off the intake boot with my hand. I'm basically down to either bad gas or an intake leak maybe? kind of lost on it. I also noticed when messing with the carb the petcock clamp was loose, so when I tried tightening it broke off. could this small of an air leak be the cause of all my problems? any help is appreciated thank you!

 

Guess you do have the air box and filter on? Spray some wd40 or carb cleaner around the intake area. If the idle lowers then you may have a cracked intake boot. The oem Mikuni is easy to rebuild and kits aren't that expensive.New Shindy Carburetor Carb Rebuild Repair Kit for Polaris 425 Magnum 1995 98 | eBay On some of these aftermarket carbs,quality may not be as good and jetting may be different,I'd check that against the original. While you're at it check the valve clearance and inspect the cam exhaust lobe. In the year range that Sportsman and Magnum cams had problems on excessive wear.Fuel valves are cheap for these also if needed. Polaris Trail Blazer 250 Magnum 425 Outlaw 525 Predator Tank Switch Fuel Petcock | eBay

 

Thank you much for your reply. sorry I took so long just wanted to wait until I got my new petcock to try everything you asked. the cam lobe looked fine to me and the valve clearance is within specs. after draining all the fule and the new petcock on I tried running the old girl again. after priming the carb and it starting it kind of spit and sputtered until it fully primed. then it was back to the high idle again. so I sprayed carb cleaner around the intake and such. no difference in idle. Ive finally found something I cant figure out and its frustrating lol. I did however just go ahead and buy a new intake boot. even though the inside of the boot looked fine. I didn't pay much for it but Id really like to get at least one ride out of it before summer ends. It might be going to the closest Polaris dealer if I cant get it figured out within the week. any more suggestions would be appreciated though as the closest dealer is a ways away!. Thanks again!

 

Only thing I can think of is recheck the carb especially the diaphragm,spring and slide area along with making sure on throttle cable slack.If the idle speed adjuster won't lower the idle then something sounds wrong in the aftermarket carb itself.

 

okay I got home from work today after thinking on it all day. went back to the basics and checked the 3 things an engine needs to run. what I came up with was a very weak spark if at all. so I guess now my question is...can a weak spark cause a high idle? I know it can cause a flooding issue, but ive never seen it cause a high idle, the only way I can get it to idle down is by choking all the air off from the intake tube to the box itself, but it is still just pouring fuel back through the carb and into the filter box, but I don't have the experience and knowledge as you. you have been very helpful and I appreciate it. thanks

 

Doesn't sound like electrical since it's running,just running too high.. If cam is good,valve clearance good,no apparent air leaks,but fuel is still pumping out of the back of the carb,still sounds like possibly the float is sticking? Anyway here's the specs on the ignition that you can at least rule it out or a problem area.. Resistance specs are +/- 20% so there is some leeway.
Stator wires leading to cdi:
Blk/Red to Green 446 ohms
Blk/Red to Red 450 ohms
Red to Green 3.2
Pulse coil specs:
White/Red to White 97 ohms
Plug cap 5K ohms

 

Thank you so much for your help on this matter. maybe you can tell me what fixed my issue. cause I did several things before I got it running perfect. went back out to the garage after ordering a new coil as my old plug boot looked kind of shotty. I brought it in and recut the wire going into the boot itself. after that I still had no spark. messed with the etc and free play a little more and got a full spark. I then started the old girl with the fuel tank sitting on the front rack. ran perfect. so I then decided I may have been pinching a vacuum or may have repositioned the throttle cable in an awkward way. I moved the cable to a more comfortable position and moved the vacuum hose going from the airbox to the oil tank threw the tank back on and the plastics in hopes it would still be running the same as it was. adjusted my idle screw as needed and now it runs like a champ. not sure what fixed it but glad its fixed. also glad parts are so cheap for this old girl. the carb or coil was probably not necessary but hey, it never hurts to have a few extra parts laying around. thanks again old Polaris tech!

 

Sounds like you had the cable in a bind. You can have the throttle slack ok at the throttle housing,good slack at the thumb throttle,but if the cable is binding under the tank you may have had too much pull on the cable at the carb causing the high idle. Found that to happen at times.Glad you solved your problem.