08 DE300 problem

[angrytim]

Hi All,

I have a strange problem w/ my 08 DE300. This happened numerous times yesterday and has happened a few times previously.
Note: Temp was near 100 degrees and about 75% humidity.

I’m riding the bike and then all of a sudden it sounds like an old clapped out 125 and loses power and won’t rev.
This goes on for a few seconds and then returns to normal. I’m sure it’s not jetting. It sounds so strange when it does this,
My thought is it is somehow getting out of time and is electrical related. I don’t even know where the CDI box is located.
Could it be the CDI is getting too hot and is having a problem?

This is not a HUGE problem for me, but could be a BIG problem if this were to happen when climbing a steep hill,
which I love to do. It crossed my mind a few times when I hit some vertical climbs yesterday. I hate that feeling when you’re
staring @ a vertical climb and worried that your bike may turn into a 88 CR125.

Any thoughts?

PS. I apologize if this is the wrong forum to ask this. I’m just not sure what the problem is.

[Jim Cook]

Check your spark plug, and cap and "wire to the coil" connections. (The cap and wires and coil all screw together.)
Then, check all the connections in the wiring harness (especially coming from the cdi, which is in the airbox, and the kill switch, which I would disconnect from the harness for the test).

It sure sounds like a loose connection or bad ground, if your plug is in good shape.

Good Riding and Wrenching to You!

Jim

[angrytim]

Thanks Jim.

[Brian VT]

Could also be a poor seal at the exhaust spigot ?

[HydroDog]

Could also be the power valve flappper sticking because of carbon. I've had mine stick wide open a couple of times. The pipe sounds real tinny and no low end.

[stay_upright]

Yes sounds like your powervalve flapper sticking open. mine has done this a couple of times as well.

The rod that pushes the cam to rotate the PV flapper (the rod that sticks up from the engine when you are looking in the RHS cavity with the cover removed I think the top of the wire where it wraps around the bolt on the cam was catching on the washer for the cam - look very closely at this and rotate the PV cam by hand - I could feel it sticking a bit and there were also witness marks on the wire and washer where it had worn a bit. I filed a flat on the washer so there is enough clearance)

[angrytim]

Thanks. I checked the electrical and all looks good. I'll check into the PV.

[kim]

One of my mates just smoked a piston on a new EC250 that had less than 8 hours on it.
Turned out that the fuel tap o-ring was blocking the gas line (in normal position) hence restricting the fuel flow when on WOT.

This only happen in normal position and not on reserve.

This was a factory assembly issue.

[LAWMAN]

is this the same thing it did that day at WP climbing that big hill? if so, I still say it's a fuel problem. I got $5 on it.

[angrytim]

Not the same thing. That was a fuel problem.