Cannondaleriders

Here is the low down my brothers 02 speed just sputtered and quit running at the dunes last weekend. It is super hard to start and will backfire some times. When we can get it to start it will run for about 2-4 seconds and then die. Any throttle and it dies right away. We spent the better part of the day checking everything out. Last time at the dunes he had problems with the quad shutting off. I think it was only like 3-4 times the entire weekend. It would loose all fire and stop. It would always restart without too much trouble and run perfect. He said that when it died this weekend it sputtered up a small hill a bit before it died. He was not running super high rpm when it died just climbing a small hill. When it died on the first trip it would just shut off not sputter. The first time he changed the oil witch was right before the dune trip we found some metal chips in the filter. I thought crank bearing but they were aluminum not steel because they didn't stick to a magnet. His motor just had a new top end done with a 460 piston and aluminum valve cover/water pump impeller. The guy that he got it from told us that he had a failure in the valvetrain and that it ruined most of the top end. It even put a hole in the aluminum valve cover that was welded shut during the rebuild. My guess on the aluminum chips in the oil filter is that they didn't clean out the frame and they and showed up in the filter from when the motor came apart. It was raining that day and the night before when we hauled it over but it ran perfect for about 30 minutes before it died. Here is what we did so far.

Full battery charge
Good fuel return flow (gutted disconnects all new lines and filter)
both injectors are firing we pulled the air box.
It has good spark (pulled the plug and checked)
changed the plug anyway.
checked the flywheel and the C lines up with the key way.
pulled the flywheel and the key is intact.
Changed out the coil on plug unit from my speed
Pulled the stator wires to to check if it would run
Checked that all wire clips are plugged all the way in and are clean
Tried to check as much of the harness as we could and didn't find any problems.

I don't know where to go next. There are a couple things we can still do but we are just looking for more ideas on what it could be.

I have an extra ECU we could try.
We can swap the fuel pressure regulator off mine.
Check compression? What numbers should we be looking for on a compression check?
We don't have a D&M kit but he said the output from the TPS looks smooth with no spikes on a mulitmeter.

Thanks Reeve.

My first guess would be a crank bearing. With my experience when they are going out they will die about every 30mins but start back up,then it gets sooner and sooner until they lock up.
It sounds like you have covered everything electoral. I've had a lose fuse connector before also a lose relay connector, but it will run with out the relay but sputter at certain rpms.
If the bike was running good at one time odds are your tps is fine. Just for grins you might want to swap out the batt you just never know.

Since this happened have you drained the oil and checked the oil filter, Do you by chance have a oil drain magnet this will collect a ton of metallic debris if any in the oil. I usuall change my oil every 2 rides or so and if something like this happened that would be one of the things i would do if something happened. Also like claas900 said change the battery. Did your brothers engine have the z-bearing put on the crank?

Well it looks like the crank bearing is toast. We got it to start back up and there is a squeaking sound coming from the motor so apart it comes. When it would die before it didn't lock up it just lost all power and rolled to a stop so I think there still might be another problem but that can come later. I think I will take the time to pull my speed apart for the Z400 and valve cover updates now that my brothers needs to be torn into. I am also going to tear into my outlaw 500 to do a new piston and rings it burns 1 qt of oil every couple tanks but still runs like a champ. Anyway thank you for the help.

hey everyone. Im new to this forum and new to Cannondales. This is my quad, Reeve has been posting about until I could get an account set up.

I managed to pull the engine and tear it most of the way down. I just need to get a flywheel puller to continue. The crank bearing is not smooth, has large amounts of play and there is lots of metal flakes in the oil. Time for the Z400 upgrade but I don't really know the best approach. Should I send this crank to someone to have the new bearing pressed in or should I just go with an assembled replacement crank with the Z400 installed?

I also noticed some other odd things. The piston skirt looks like some of the metal chips got between it and the sleeve and made the skirts a little rough and the sleeve has some minor wear from it as well. Other than the minor wear the piston and sleeve only have about 20 hours on them and seem to be in great shape.

And the clutch friction plate that is closest to the basket has some wear and bending on the tabs where it looks like it has contacted the radius that is on the mating tabs on the basket. Just wondering if this was normal and if not what could be causing it?


Thanks for the help. I will take some pictures of the questionable wear and post them up when I can dig up a camera

No point on posting picks. If driven to failure the crank ,piston ,sleeve, and most likely scavange pump rotors are all destroyed and need to be replaced. The frame will need to be completely flushed and pressure washed out to get most of the steel fragmants out or they will go right back into your next engine.

The inner friction plates tend to bend over the tabs. Inspecting them through the fill plug and rotating them to the other end of the stack is normal maintenece on those.