Idle problems and intermittent bogging down

[Captain Ken]

Have an Arctic Cat Wildcat 1993 700 cc engine. I just got it used. No idea of history, but supposedly it was maintained well and had "$700 worth of misc work last year." Who knows.

Symptom problems are as follows:

1. Starts fine. Idles OK at first. When I go to hit the throttle, you kind of have to finesse it, sometimes hitting the choke, or it'll die. Then you finally get up and run. When you first slow down, things are fine, but then she'll die unless you futz with the throttle and choke again.

2. During higher speeds (say 20 mph) it will kind of bog down at times. Almost sounds like a misfiring, but plugs look good. Throttle all the way open and only about 5000 rpm and NO power to speak of. Sometimes the track barley moves and sometime it does not move at all. Smoke up the wazoo, my guess from lots of oil being pumped into the engine due to full throttle. Seems to be a little more predominant under a load (up a hill, with me and my wife (400 lbs me being 260 of it), but can also happen on a flat surface. Wife has to get off, I get off and try to coax it up the hill (invariably happens in a really crappy spot). Eventually it takes off. Then may run just fine for 15-20 minutes (except for the previously mentioned idle problem)

I put in a good 1/2 can of sea foam to 3/4 full fuel tank (91 octane non-oxy), that was mostly fresh fuel. No change in either symptom to speak of.

One idea put forth to date is fuel filter and fuel pump replacement. I'm in IL now and we apparently don't sell rebuild kits for the fuel pumps here ("It's just as expensive as buying a new one sir."), so it's $35 X 2 of em for my sled according to my friendly local dealer.

Before I go forward I thought I should hear from you guys (and maybe gals)who I trust WAY more than myself and the dealer down hear.

Thanks! I'm new at this snowmobile stuff.

Ken

[Guest]

I have an EXT 580 that has the same bogging problem after idle and you have to hit the choke deal. I have isolated the problem on mine as a fuel pump. My sled can periodically just not start as the fuel pump fails, and/or it's a weak stream. I have a new pump to install when I find the time.

I also MIGHT have a fuel pump kit that you need. I have it from an '87 El Tigre that had 2 fuel pumps. See if you can get the part # you need for the repair kit. I don't think I have a need for the kits, but I have to see.

Turns out that my El Tigre had fuel pump failures too.

5000 RPM's and no power?? Clutch problem?

I've had similiar performance issues. I reset the needle jets, changed the main jets on the carbs for the right temperature, elevation, etc... Some machines are fussy with temps. I tend to run them slightly leaner.

You can also get everything you need on dennis kirk, a snowmobile parts company. Pretty much everything you need (filters, pumps, etc..) Do a search on the web for it.

[Captain Ken]

Thanks CD. I'll check on the parts number and get back to you.

Generally, how does one know if he is having a clutch problem? Are there certain symptoms, things to look for, ways for me to check it out before pursuing a fix either myself or through the shop/a mechanic. Replacing things like fuel pumps I think I cna handle, not too sure about clutches or ripping apart carbs yet.

Also, I am wondering if I even have fuel pumps. I know I have carbs. I thought I just had the 700 cc plain model vs the EFI. As I trace the fuel lines around, I see these two squareish things mounted in the engine compartment after the fuel filter and before the carbs. Look like they have four screws a piece. As best I can see (they are under the air box) there is a fuel line going into each and then out to each carb. So, what are those?

I appreciate all the info as I am on the learning curve as far as engines in general go and especially as far as snowmachines go. I want to take a small engines course, but there is only ONE PER YEAR offered here in northern Illinois, and of course I have to wait for fall to take it. So, for now I am depending on people like you, reading and my own reasoning abilities!

Ken

[This message has been edited by Captain Ken (edited 12-01-2003).]

[rmh2o]

Captain Ken Those 2 square things you are looking at are your fuel pumps,I just had a similar problem and it was the fuel pump but what you are describing sounds more like a clutch problem.

[Steve Bakken]

Ken, as long as you have to tear it down far enough to get to the fuel pumps, it really would be a good time to go through your carbs as well. I've seen a dirty carb burn down a motor in a matter of minutes. I religiously do mine once a year. I know it's a very intimidating job to tackle the first time, but I'm quite confident that if you take your time and just pay attention to how things go together you'll do just fine. Remember, if you do one at a time, you've always got the other one as a reference. A couple of pointers-

* There are two cables going into each carb. The one with the big collar is the throttle. Dont worry about the little nuts that attach, just unscrew the big collar and the whole throttle cylinder will slide right out the top of the carb. Same with the choke. Just turn the bottom-most nut and the choke cylinder will do the same thing.

* Get a good quality aresol cleaner. The best one I've ever used and still use to this day is called Bonefide and is made by Drummand-American.

* Loosen the four screws on the bottom to take off the bowl. You'll see the little brass jet staring you right in the face. Remove that, and also a tiny little screw which is in a recess right next to the jet.

* Spray that carb cleaner through every stinkin orifice you can see. Through the jet, the orifices in the little screw, and all the holes in the carb body. Also soak some in the bottom of the bowl.

* Make sure your floats slide up and down freely. Sticky floats can cause some of your problems too.

It's really not too complicated. After you've done it once, it'll be a cakewalk.

Anybody else have any pointers or suggestions that I might have missed?

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Steve @ Bakken's Boat Shop www.bakkensboatshop.com

[Mueske]

If you can't find some friends who know how to do their own maintenance take it to a dealer. It might cost you some money but save you much aggravation. I couldn't imagine that my wife would have put on the miles she has on a sled if she didn't have a good experience on her first few rides. Breakdowns occur but preseason preparation make sledding more fun and less dangerous. In the Rockies we are often more than 50 miles from businesses at the trailhead, further than that from others that can assist when broken down after dark. In short, take it to a dealer until you know how to go over it system by system. Pay attention to what they are doing, visit websites where you can ask questions about sled maintenance and offer to assist buddies in working on their sleds. Sleds are not complex and you seem bright and willing to learn. Hands-on experience is best but you must first experience the thrill a well tuned machine can give you to keep you interested. I have family in northern IL that are no strangers to sleds and have been running them (when snow is available) since the 1960s. They can't be alone so find others to ride, tune and talk with. Good luck.

Kevin

[Captain Ken]

Thanks for the additional tips and confidence guys. Gosh, this whole burning up the engine thing has got me paranoid. Sounds like I will need to become a carb expert here in the near future so I don't have to obsess over that day and night (I tend to get that way sometimes). I suspect it is like a mind over matter deal and with a few manuals and your advice and possibly a friend I think I can do it.

I really want to learn for 2 reasons. #1 The dealers around here in IL are really expensive and it's kind of a "just drop her off sir and we experts will tell you what's wrong with it." $$$$. Also, whereas the rebuilding kits are like $6 they want to sell you new fuel pumps for $35 a piece ("Kits cost just the same sir."). Must be new math, since $12=$70. #2 Our place in MN is out in the woods with nothing back there but me and my head. If somthing breaks in the woods or out on the lake, I figure the more I know and the more self-sufficient I am the better. Fortunately, there is an Arctic Cat dealer in Tower, MN who seems to be a nice guy and who I would not mind taking my sled to when I get over my head. He's not too far from us when we are in Tower, but 10 hours from me when I am at my home (where I live in IL).

The wife's a trooper and she tolerates my "adventures" pretty well, so we can laugh about her having to walk up the hills, for now.

I'll keep reading and keep you guys posted. If only there were snow in IL.......

Ken

Anyway, I appreciate your

[Guest]

The Cat mechanic in Tower worked on my sled a couple times when I lived in Ely (in 1994). Great, honest mechanic. He was really the only mechanic to fine tune my sled and get it running properly.

If you have square fuel pumps on your Wildcat, my kits will not work on your pumps.

If you feel up to it, take the carbs apart and clean out all the fine jets like Steve said. Fine tuning both carbs can be tricky, so if you don't know how to do it have a pro do it for you.

P.S. Have you tried new spark plugs? Those high performance sleds burn plugs up all the time, at least on some of my sleds. Carry lots of spare plugs at all times!!

[Surface Tension]

I agree with Steve. I'd add replace the filters of coarse and all the fuel lines. I'd also drain the tank and remove it then replace the the pickup lines and ends inside. Sured be nice to know what put the money into. What you described sounds like its starving for gas except the smoking part which sounds like it loaded up unless your smoking the belt? A compression test would be nice. Get yourself a manual thats specific to your year and model sled along with a carb breakdown.

[Captain Ken]

**UPDATE**

Thanks for the tips. Here's the plan. I called the guy I bought it from and I got the dealer's name where he took it for svc. I am going to make a visit there and see if I can talk real nice and get a look see at the service records. I asked the guy I bought it from what he had done last year. He couldn't remember but recalls it was 6-700 bucks worth (believe me for that price I'd remember the part numbers).

Then, I am getting a friend of mine to help me tear down the carbs, clean them etc etc. We will also rebuild the fuel pumps. I am also replacing the air box cause it has a couple cracks in the rubber where it attaches to the carbs. While I am at it I will suck out all the fuel in the tank and replace with 100% fresh. Probably will suck out all the oil too and replace that. What the heck. Will synch the carbs or have someone do it and then see what happens. Oh yeah, new plugs too.

I imagine this will all take a couple weeks or so to do. I'll keep checking here and also post updates as they develop!

In any case, I'm planning a trip to Tower in teh first week of Jan so I will have it all done by then, Christmas or not!

The smell when all the smoke was billowing up smelled like oil to me. My theory was that there was not enough gas coming in even though the throttle was open and lots of oil was being dumped in to match the gas that was supposed to be there. Or, it was only working on 1 cylinder. Who knows, I'm new at this. It did not smell like rubber though.

I suspected the Tower AC dealer was an honest guy when I went in there to buy 2 stroke oil, picked what I thought was the right one, but he questioned me as to what I was needing it for. When I told him he said, "Well you could us that but you'd just be spending more money than you need to. This one here will be fine for your machine."
And he took the expensive one back and gave me the other one. I was thinking to myself, whoa, that never happens in IL where I live.

Thanks!

Ken

[rmh2o]

Captain Ken take a look at your clutches are they clean where the belt rides? Do your clutches open and close when you increase RPM? Is your belt worn and sitting lower in the clutch?

[Captain Ken]

rmh,

I will look into all this. The belt looks pretty new. I think that may have been one of the items $700 bought. As for the opening and closing part, I'll check this further. I have been reading some tech tip type pubs on this, how the clutch works etc etc. Will update as work stops interfering with important things like snowmobiles, fishing, boats and the like and I have some time to fiddle. Looks like 12/14 will be the big day for the tearing down of my machine as my engine mechanic friend will and I will both be free that day.

K

[rmh2o]

As Steve stated above the carbs can seem intimidating but in fact they are pretty simple to work on.If you remove float bowl carefully and dont tear gasket you can reuse it.A lot of times that recessed jet he mentioned can be plugged it takes a small straight screwdriver to remove it.Before removing outside jets screw in till it stops counting turns then write it down so you can put them back to the same setting.

[David Swenson]

Ken,

Whenever there is a problem, put in new plugs. Even if it appears you have good spark. If this does not fix the problem, then go on to other fixes.

Just had a similar problem. Check fuel system, checked and cleaned spark plugs, drained old fuel, put in sea foam and no change in condition. Put in new plugs, it ran like it was new.

Dave

[EXTREME]

I hate to even mention this to you, but I would check the compression...it almost sounds like one cylinder is bad. Sometimes when you have to hit the choke to keep it running there is a compression failure. An easy way to check this is take out the plugs and stick your thumb over the hole and pull the starter rope...if you feel good pressure, they are probably fine. I hope this does not scare you but it could be the problem. Another question to ask....does the engine go to 7-8000 rpm's? Does it pull out of the bogginess (sp) after a certain rpm? If it does, then it is definately a carburator problem. Either way, do not run the machine much, plugged carbs lead to scored pistons. Check the compression with my test and let me know....I hate for you to go through all that work on a "dead" horse.

[pj4]

if you do the pressure test as stated erlier. test both cly. with plugs out and note the diffrence in compression. same is good, diff amount is bad.my artic cat was very sensitive to spark plugs.

[Captain Ken]

Thanks for the additional tips guys. I will definately look into the plugs and test compression. I had thought about compression as something to test, but kind of avoiding it (denial isn't all bad). I never was able to go all the way up to top end cause Lake Vermilion wasn't frozen enough for my comfort and there were too many trees to risk it around my place. I don't have a compression tester but I do have two thumbs. Will try that first, I suspect my friend has a tester since he works on stuff alot, so we'll do that officially before ripping into things if for no reason other than to confront the anxiety of poor compression as the cause and deal with it one way or another. Spoken like a true shrink, right Dave?

Would a compression problem be intermittent?

Ken

[Captain Ken]

Thanks for the additional tips guys. I will definately look into the plugs and test compression. I had thought about compression as something to test, but kind of avoiding it (denial isn't all bad). I never was able to go all the way up to top end cause Lake Vermilion wasn't frozen enough for my comfort and there were too many trees to risk it around my place. I don't have a compression tester but I do have two thumbs. Will try that first, I suspect my friend has a tester since he works on stuff alot, so we'll do that officially before ripping into things if for no reason other than to confront the anxiety of poor compression as the cause and deal with it one way or another. Spoken like a true shrink, right Dave?

Would a compression problem be intermittent?

Ken

[Steve Bakken]

No, compression does not fluctuate. It may improve slightly as the engine warms up and the piston expands, but it is consistant. You don't need a real long stretch of ground to check rpm's. The clutch is designed so that anytime you are under full throttle, the engine should climb almost instantly up to the engines peak power band. (usually around 8000 rpm's.)

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Steve @ Bakken's Boat Shop www.bakkensboatshop.com

[Captain Ken]

UPDATE

Thanks Steve for the additional info. Well, I have all the stuff to do the big carb job, new plugs, fuel pump, the works. Even new rubber boot piece for the air box side of the carbs has been ordered (some cracks on the old one). On 12/14 my friend and I will tear into her. Actually, the parts guy I happened to deal with at the dealer here in IL was very helpful. So, I take back all bad things I even said or thought about them. He gave me a big in person lesson to augment everything you guys have taught me! I am actually starting to figure this all out! Who knows, it might be "Good bye psychology. Hello small engines repair at some point in the future." OK, maybe I better stick with psychology, at least till the student loans are paid off......

Stay tuned!

Ken

[Captain Ken]

UPDATE

Took carbs apart and cleaned, changed plugs, changed fuel pumps (replaced the 2 singles with one dual), new fuel. Started her up and viola, same problem with idle.

Fiddled with idle screw, air screw, messed with the choke assemblies all to no avail. Works great up on a jack stand under power, but idles like dump. Just seems to run out of fuel. So, our new theory is that we will retake apart the carbs and replace the idle speed jets. I have gotten the specs from the very nice guy at Mikuni- It indiates that the idle jet should be a 50. The high speed should be 400, and it is. We see evidence that someone has been in the carb before and the writing on the jet was really teeny, but I think it said 28. So, we are thinking that the reason we can't fix the idle is that there is too small a jet. This would explain the running out of fuel on idle symptom. It's also possible that they are the right number but something is clogged in there or onf of them is out of whack somehow. So, we are going to just put new ones in.

This Sat is the big day for round two. Meanwhile my friend (left it at his house) will be taking the carbs apart again and finding a magnifying glass to try and read the little numbers. It'd be cool in a way if they were the wrong ones, cause that would make it simple and we'd walk away thinking we are great detectives, with all of your help, of course.

I'll keep you posted.

Ken

[Captain Ken]

UPDATE #2

Called my buddy. He took carbs apart again and the jets were in fact 50s. He decided to readjust the chokes. Dropped them all the way down to the point there was no tension from the spring, then brought them up about 1/2 - 3/4 turn. Now she idles just fine. He said it ran like a sewing machine for about 10 minutes. It's a little warm here in IL so it's running a little richer than it will in MN where I plan to use it most. So, maybe we're in the clear.

Thanks again!

Ken

[Steve Bakken]

Glad to hear it. It may have been a bit more time consuming, but isn't it a good feeling to know that you fixed the problem yourself without having to spend all that money? Good justification to the wife to get to spend it on something else that you want.

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Steve @ Bakken's Boat Shop www.bakkensboatshop.com

[Captain Ken]

Update #3 or 4
Just when you thought it was running.....

Got it up to my place in Tower after she was running fine in the garage. Wouldn't start. It was, however, -5. No spark, then spark. Hummm, am I losing my mind or what???? Gave up and went to Cliff's for coffee. Then to Tower to get a little wire with alligaror clips on it to jumper some stuff out. Came back, started in 1 pull. OK, maybe it was flooded, I thought. Who knows at this point. Rode her down trail, and ran like a top. Then, the bogging down began again. Again sounded like it was running on 1 cylinder. Backfiring, sputtering the works. Died all of a sudden, like someone pulled the kill. Now what? How will I ever get this thing out of the middle of my trail and up on the trailer again.....??? Set trailer up and eventually got her started again. Cough and sputter all the way up on the trailer. I've had my fill, I concluded and decide to take it to Harold's Artic Cat (there was a reason I got an AC since my place is in Tower). He listens to my plight and says he thinks he knows what it is. Rips into teh sled on the spot since he wants to get me riding for the weekend. Jumpers out different things untill he gets to main wiring harness (which was pretty corroded). Jumpers out everything at this juncture and she runs like a top. Some sensor or connection somewhere that is telling the ignition to shut down - not the slide sensors in the carbs but something else. They tried to fix it so I could have it back for the weekend, but could not isolate the problem specifically on the spot. So, Harold has it now.

So, it sounds like we had two problems- one fuel (which we fixed) and the other electrical.

In my experience, not often a shop will rip into anything on the spot, so I am indebetted to them for trying.

Captain Ken

[Steve Bakken]

I had an old Yamaha that had exactly the same problem. Turned out to be the ignition coil. Where the plug wire goes into the coil there was just enough of a crack that you couldn't see it, but when the engine got warm, moisture condensed on the unit and shorted out the spark. Exact same symptoms. Popping, chugging, one cylinder running. The epoxy around the spark plug wire and the coil has a tendency to crack on older units. Get it running and spray some water on it. If you get a reaction- voila!

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Steve @ Bakken's Boat Shop www.bakkensboatshop.com