davefrombc

While you're in there I'd change that timing sprocket too. It's showing a fair bit of wear .. Yes, you want those guides in place to keep the chain from jumping on the sprocket and throwing the valve timing out. I don't know about that motor but on some motors if the valve timing is out or the chain is broken the piston can hit the valves.. and good bye motor. Was the keyway in the crankshaft damaged? You could be looking at some major repairs to the motor with a new crankshaft in the works if the keyway is slopped out .

As far as oil is concerned, you likely can't go wrong with a 10w40 (MA in the specifications) suitable for motorcycles in the engine and a 75-90 hypoid oil in the differentials. According to other forums on engine oils avoid the "Energy conserving" oils. They have friction reducing additives that can screw up wet clutches.

According to a post in another site : Try looking on the upper frame tube on the rear left side under the wheel well. As Frank says .. There's one somewhere on the frame. Try looking for a number on the motor too. It might be possible to id it from that .

Bring the piston up to TDC on compression. Watch the valves as you do it. When it is TDC compression, both valves will be closed. If you take the spark plug out you should be able to see into the cylinder to confirm when the piston is at the top. If you can't see the piston , you can use a dowel or even a pencil to feel for the piston reaching the top.. Be sure to turn the motor over slowly by hand. You don't want to break off the dowel or pencil in the cylinder.When you see (or feel) the piston at TDC then you can look to see what line most closely lines up with whatever indicator there may be. The piston doesn't have to be exactly at TDC to set the valves , but it must be close enough that both valves are closed, and not beginning to open ... There are a few degrees rotation after the intake valves have closed and before the exhaust valves begin to open.

If your compression is down around 40 PSI then there may be nothing wrong with the clutch. . The engine isn't producing the power necessary for it to work properly. Check the valves and gaskets first as Frank mentioned. Bring the motor up to specs and then see if you still have clutch problems.

I took a quick look at a review of that quad. Since it is fuel injected there should be a fuel enrichening signal while the motor is cold . My guess would be either a sensor is not working to give it the signal, or possibly because the quad is designed principally for racing it doesn't have that feature .. Having to give it a little throttle until it warms up is no biggie to me. If you're looking at the quad more as a trail rider than a racer, be aware that it has no reverse.. You need to manhandle it back if you get in a sticky spot.. That to me would be a deal killer since I am not a racer, and I definitely need to back up quite regularly.

Great to learn you got it running ok.. I see with that picture it is the rotor itself that is keyed to the shaft and the gear behind bolts to it, so now I know why there was no mention of how it was timed.

2004 Bombardier DS650 service manual View File 2004 Bombardier Service Manual Submitter davefrombc Submitted 07/28/2017 Category Other ATV  

I found a service manual for the Bombardier DS650 and downloaded it to the "Other ATV" in the service manual list. I'm not impressed with it as far as the ignition system is concerned.. There is no timing mark for the magneto. There is nothing stating where the magnet and pickup coil should be positioned at TDC. Just the gap is mentioned.

Since it works as a magneto, I would say after. Ignition systems usually fire a few degrees before TDC to give maximum power. The higher the rpm, the earlier the spark . . Low rpm motors sometimes use a retarded spark for bottom end power . The magnet of the trigger pad should pass the pickup before the piston reaches TDC to produce the advanced spark. The manual should specify the timing , and I would suspect there should be a timing mark on the gears.

OK... That is not good .. Check to see if possibly the key on the rotor has sheared and allowed it to turn on the crankshaft. That would explain why the magnet is nowhere near the trigger coil at TDC compression. "Dumping the clutch" several times could have caused the motor to abruptly drop in RPM putting a lot of inertial torque on the rotor subsequently shearing the key ..

The only thing I could think of is it somehow firing on TDC exhaust rather than TDC on compression ? You seem to have eliminated everything else .

Since it is a new carb it should be ok, but check to be sure fuel is getting to it. Tank valve could be blocked or partially blocked.. crap could be in the line , if you have a fuel filter on it , check it is not plugged . For those working on cleaning carbs and jets : instead of using a piece of copper wire or a strand from cable , go to a welding supply store and buy a set of "tip cleaners" they will have various sized cleaner wires that fit pretty much every size orifice you'll find in the carbs. They're much more convenient and better for the job.

I did some searching on your backfire problem and dirty plug... I don't know your year , but according to other forums the Phoenix has an Electric Throttle Control (ETC) to protect against over revving. Here is what others had to say about it: It could be something as simple as the throttle cable stretching and getting loose. Newer Polaris machines with the wires going into the throttle control have what they call an ETC control. What it does is activate a rev limiter (the newer ones may cut the spark entirely) if for some reason the throttle sticks partially open. Sometimes if the throttle cable stretches enough, it will activate the ETC even if the throttle isn't stuck. Set the cable free play and see if this helps. Backfiring can also be caused by too rich fuel mix, as well as several other possibilities, but the most common cause for backfiring in a Polaris I found was excess throttle cable slack causing the ETC to activate. And one other's solution : I am/was getting backfire on my Phoenix 200. I have a 2006, and supposedly that issue was with 2005 and newer, but it happens on mine when releasing throttle from WO... After reading about the ETC, I open the cap to the ETC, and put a shim in there so the contactors don't touch, and BINGO it fixed the issue.... this has to be the cheapest fix I have ever done - 2 cents for a piece of plastic, and 5 minutes for labor. Engine purrs like a kitten, and no backfire on deceleration. I know this is a somewhat of a safety issue, because if the throttle breaks it's suppose make the contactors touch each other causing the engine to go idle speed, but I'll have to take the chance... I'd rather not having the backfire issue... can't b too good for the engine. Looking for info on the oil separator, brought up info that the crank case is vented to the air box. The oil separator is supposed to keep crankcase oil from being drawn into the air box. There is no pcv valve. They noted in the forums where it was discussed that if the crank case oil is a little too high oil could be drawn up. Is your air box excessively oily ?.. That could be part of the problem. From what I read , and your initial description, I'd look at the ETC if your machine has one. That sounds the most likely culprit for the backfire and carboned up plug .

Black plug usually means too rich, or misfiring / weak spark .. White and "glazed" too lean or too "hot" a heat range .. Normal plug should be greyish or a light tan colour.

It could be a component in the CDI box or the coil breaking down as it heats up .. Capacitors occasionally go bad .. There is a tester you can get to see if there is constant spark.. It is a goody that goes inline with the spark plug wire. It has a window you can see the spark flash in. Here is a picture of one version . Search Google for "spark tester for ignition systems" for vendors .

Make sure the quad is in neutral, check there is power to the ignition switch, then the process of elimination starts at the battery positive and ground and works through the circuit. You can quick check the starter by running 12 v directly to the terminal momentarily to see if it spins over ( assuming you at least have power to the lights and indicators) Usual problems are bad grounds, broken wires and corroded terminals, or defective relays. Check in that order. Electrical problems can sometimes be a real PIA to trace out .

If it is doing it without a load on it ( being driven) it could be a restriction in the fuel getting to the carb .Level dropping to the point it is running lean and then quits.. after a few seconds , enough fuel reaches the float bowl for it to run again for a short period.. If it is when being ridden, it might be a component in the ignition system breaking down as it heats up. Those are my two stab in the dark guesses.

Try rocking it a bit while trying to take it out of park.. It may be binding a bit if the quad is on a slight slope. I have a friend with a Kymco 700 and he has had to do that occasionally.

Just do a search on "94 timberwolf rear brake drum" .. There are a number of suppliers that come up, with several offering free shipping in the US. Prices vary a lot between suppliers .

Arctic Cat Prowler 2007 Service manual View File Service manual for the 2007 Arctic Cat Prowler Submitter davefrombc Submitted 07/19/2017 Category Arctic Cat ATV  

Searched for your manual and came up with this site. http://www.mymowerparts.com/pdf/ It has service manuals for all sorts of equipment , including the Arctic Cat 700. I'll add that manual to the list in QC's downloads folder.