F
Had a similiar problem on my sons 900. Ended up being the pre filters on the fuel pump in tank.The filters have screens and plungers in them and were gummed up real bad worth a check
new to site please help
- Thread starter sheldonconnor
- Start date
T
My old 800 did something similar, it turned out that the stator was bad.
A
I think everyone has given some great things to check. This is totally off the wall here.
But it almost sounds like a clutching problem or a drive train problem.
1. pick the backend off the ground and see if you can pull the track over by hand. Could have a drive shaft bearing causing extra drag, and messing with your backshifting and clutching.
2. Check the weights and operation of the primary
3. Check the secondary.
I had a 600 efi and I had some issues with the primary, it idled fine then when I nailed it it would bog, but if the load was minimal (ice or hard pack) it would sometimes pickup and go. Then if the clutching is messed up (gummed up) it would do the same thing on the top end when it needed to backshift. So who knows but it's a shot in the dark.
I really like the stator, fuel pickups, fuel pressure as the primary targets.
O' after you make sure the exhaust and intake is clear of course.
Thunder
But it almost sounds like a clutching problem or a drive train problem.
1. pick the backend off the ground and see if you can pull the track over by hand. Could have a drive shaft bearing causing extra drag, and messing with your backshifting and clutching.
2. Check the weights and operation of the primary
3. Check the secondary.
I had a 600 efi and I had some issues with the primary, it idled fine then when I nailed it it would bog, but if the load was minimal (ice or hard pack) it would sometimes pickup and go. Then if the clutching is messed up (gummed up) it would do the same thing on the top end when it needed to backshift. So who knows but it's a shot in the dark.
I really like the stator, fuel pickups, fuel pressure as the primary targets.
O' after you make sure the exhaust and intake is clear of course.
Thunder
C
Pretty sure its the fuel pump starting to go. Mine and a buddies had the same issues. Call Twisted Turbo, he throws away or has a pile of intank fuel pumps from newer M's that I am sure you can make work, sure he would give you one or sell one to you cheap.
Good luck!!
Good luck!!
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If its EFI i would also check the ground wires, I would also get the ignition coil tested. It could possibly be one of these, however I had the same thing happen to mine on a couple of occasions then it would clear up no problems rest of season....so I'm liking the suggestion that it could be the pick up filters in the tank or the pump as well. Hope this helps
S
K guys I took the sled out for a good ride and ran a can of that sea foam injector cleaner throught it and tried to figure out when the bogg would happen. I can be going across the lake playing with the throttle on and off and I have all the power in the world. As soon as I hold the throttle 3/4 open or even wide open it Boggs out but if I let of the gas and punch it the power comes back but then starts to bogg out again. We don't have much snow here at all but when I try to carve In The snow also it Boggs out. We might have a foot of snow. These are things I just figured out when I went out for a ride. I find also if I'm in a bit of powder and punch it where the front end want to come up it Boggs just I would throw that in there also
H
You have to figure out if it's short on fuel durring the bog.
Kill the engine after holding the throttle on the bog, then ck the plugs. Wet/ dry? I'd guess dry, water in fuel, plugged line or crack in line, whatever.
Wet, probably a bad plug or wire.
Owen
Kill the engine after holding the throttle on the bog, then ck the plugs. Wet/ dry? I'd guess dry, water in fuel, plugged line or crack in line, whatever.
Wet, probably a bad plug or wire.
Owen
S
Hi guys I finally brought the sled into a buddies shop and checked it out. The servo is working and the apv valvles are also in good shape. Checked the screens on the tank and it's also fine. My buddy took my belt of my sled and fired it up and gave it a shot of gas and the sled stayed at 5000 rpm. Could this mean it's a clutch issue. I also fou d the sled won't go past 7000 rpm and will start to bogg right out like its running on one cylinder. If it was a clutching issue and it was sticking would it feel like its only running on one cylinder. Also when I let of the gas and punch it it gets the power back and starts to bog out or even if I just punch it on take off it bogs out. Or could it be the tps sensor is out of adjustment
D
I doubt it's a clutching issue, if it was load on it not just rpm clutching would come into play. TPS is a position related thing and is not strickly a rpm thing, I hope you understand what I mean. If the throttle is always in the same position when it acts up it would be suspect. I believe you said the dealer had check that and it's pretty hard to screw that up unless he had a low battery on his tester. I would get a friend over to help and put the nose against the wall, raise the back, pull the air box and start running it. Try adding fuel as you open it up and see if it,s just a fuel feed problem. Also watch the servo and make sure it stays open once you get past 6700 R's. I've seen them open and close again. Keep the belt on and the track spinning, you can put some load on it with the brakes. I had a servo motor go on a 600 once when they first came out with them. I didn't know much about them so it went to a dealer. He worked all day testing it and could not find anything. I borrowed a ecu off another guy, didn't help, then I borrowed a servo put it on and all was right with the world again. The dealers test showed it worked right. Good luck, it's gotta run pretty soon!
T
diggerdown is right about keeping the belt on when diag. a concern. On an efi engine, with belt off, you can hold the throttle wide open and it will begin to cut out or "bog" with no load on the engine at high rpms. Something with the fuel mapping and engine spinning freely. Your concern sounds real similar to an 02 mountain cat we had. Found the stator was coming loose causing incorrect timing. Assuming fuel psi and all other suggestions above checked out, i would check the timing.
D
Now that you mention that it could even be a piece or recoil cord wedged in the flywheel or stuck between the trigger and pickup. He's a little to far away to go give him a hand with it.
C
I agree;
They are called "smart valves" and what happens is they are designed to close when one of them is uncovered due to the fuel sloshing around when the tank gets low. Sometimes they will close when they shouldn't. Cat changed the design about 4 or 5 years ago to fix the problem. If you want to check to see if this is the problem, fish the one on the end of the long pickup hose out with a long wire or coat hanger. You can take the screen off and either remove the diaphram or make it so it can't close. snap the screen back on and try it. It won't cost a thing to try. Maybe the dealer already tried it, it was a common problem a few years back.
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C
It is fuel, again betting bad fuel pump. Just put a pressure gauge inline with the injector bar and watch the fuel pressure (I believe it should be around 40 psi). I am saying fuel because it drops a cylinder, likely because it is not getting enough fuel. Did have a cracked spark plug that would drop RPM under load, but that doesn't sound like what you are describing.
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Start at the beginning.
I assuming that the clutches have been looked at?
1st Check clutches make sure all weights are good. Looking for ruff looking wights or bad roller or even cracked spider.
2nd fuel system tank and pumps you can hook a gauge to check presure
This is my thoughts . I think its an RPM thing or is it?
Will it ever rev up if you put it on a stand will it tack? at what point does it start to miss? I am assuming that you did this when you check power valves?
I assuming that the clutches have been looked at?
1st Check clutches make sure all weights are good. Looking for ruff looking wights or bad roller or even cracked spider.
2nd fuel system tank and pumps you can hook a gauge to check presure
This is my thoughts . I think its an RPM thing or is it?
Will it ever rev up if you put it on a stand will it tack? at what point does it start to miss? I am assuming that you did this when you check power valves?
S
It only Boggs out when your driving it. It won't bogg out when the *** end is up in the air only when there is someone riding it or a load in the track. Like I said if I play with the throttle I can get the rpms up there but it's like it kicks out and starts to run on one cylinder. If I let off the gas and punch it again the powers there the will start to bogg out again Also if I'm in a foot of snow and kind of punch it to carve it also Boggs right out. If it was the wrong weights in the clutch what symptoms would I see. I reall appreciate all the help guys I bought the sled for 4 gs and the shop bill was almost 2 gs. I'm sitting at like 6 grand and nothing. Thanks
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D
Now it does sound like a fuel issue. If the fuel pressure is low usually the mag side injector starves for fuel. NO real load and it revs up, doesn't take a lot of fuel with no load. You need a pressure guage on it so you can see whats going on. If the tank was left empty for the summer the pump and valves are probably shot, never let an efi sled sit dry for long.
S
How hard is it to change out the fuel pump. Does a shop need to do it or could I change it. What is the price of a pump?
D
Fuel pumps are expensive but are easy to replace. You really want to know if that is the problem before putting one in. You just unscrew the cap on the fuel tank and lift the pump out. Go to babbits or countrycat.net and look up the parts for it, you will see how it all goes together and mail order prices. They run around $250. You should be able to find a pressure guage to hook into the line for less than $20 and be able to see what you have. I would have thought the dealer would have check that, but it sounds like he is a very bad dealer. Feel for yah man.
C
I already said this, but if you can use an M fuel pump, the turbo builders throw away the stock M pumps by the buckets.....
C
Ok, I am sticking to the fuel pump, but one thing that you can try is bypassing the keyswitch. The key switch is known for causing intermittent issues under load, in fact I have bypassed it on every Cat I have owned since my '94 T-Cat!!
