High speed bump performance change?

[lvermey]

Hi 2t gurus, I need some help. I have a new to me EC300 08.

The fellow I bought the bike off of told me the float needle jet was leaking. I fixed that by just cleaning it out. Checked the float level and it was at 16mm. I got that measurment from the carb site. Then on my second ride I was going down a trail in 4th or5th gear at a good clip but not on the pipe, say mid rpm range. Then when I hit a 3" to 6" rock or root the exhaust note would change to pap pap pap... and I would lose half of my power. So I backed out of the throttle, shifted down, then rolled on the throttle until I hit the pipe and it seemed to correct its self. Doesn't do it every time, but anytime is to often.

The only things I can think of are: Carb, exhaust valve/power valve ( are these the same thing?) or reed valve?

I hope some one can help!

Len.

[scrambler250]

My '07 300 does the same thing. It feels and sounds like a 125 when it happens. I'm pretty sure it's the power valve. I bought mine used, and after it did this the first time, I took the power valve apart, and cleaned a bunch of carbon off it. This helped for awhile, but it's progressively coming back. I meant to talk to the gofasters guys at a couple nationals, but never made it. I've also not had time to research further on this board. I'm running bel-ray H1R at 50:1, if it matters.

[lvermey]

I am going to do the same. There is a thread that sounds like the same condition on this site. I have decided to do all the things one should do when you buy a used bike. I have started with the muffler, which the guy said was due for a repack. And boy it sure does. Doing my second over night soke with easy off overn cleaner to losen all the carbon up. I will then have a look at the power valve. My father inlaw is a rider and a master mechanic and he said to make sure all my carb vent hoses are cleared as well, and go over the carb completely. I'm running MotorX 100% synthetic at 50:1. The previous owner ran something else at 60:1. I talked to the dealer, and he said that with the synthetics you can run it at that ratio which is 1% instead of 2%. But he said I should stick to the 50:1. I will let you know if I make any progress.

[Brian VT]

It's usually not the oil ratio or brand that causes spooge, your jetting needs to be correct.

[iajim]

One small note here. Don't get yourself confused with the oil percentages(1%, 2%, etc.) 1% is 100:1, way too lean on the oil and your jetting will be too rich. I would guess carb vent hoses for the problem you described. Let us know what you find. Jim

[lvermey]

I believe I have solved the problem! I started with the PV. It was completely encrusted in carbon. I must have spent 2 hours just cleaning it. When I opened up the right side the actuator arm would stick 2 thirds of the way to the top every time I moved it up and down. Once clean and back together it moved nice and smoothly. Went for a ride today the bike ran perfect. I did not touch the carb because I wanted to know what fixed it. The PV didn't do it, then I would have went on to the next item on the list. I guess with a 2t that will be one of my routine maintenance jobs.

Thank you all for your help, much appreciated.

Len.

[John T]

Originally Posted by lvermey

I believe I have solved the problem! I started with the PV. It was completely encrusted in carbon. I must have spent 2 hours just cleaning it. When I opened up the right side the actuator arm would stick 2 thirds of the way to the top every time I moved it up and down. Once clean and back together it moved nice and smoothly. Went for a ride today the bike ran perfect. I did not touch the carb because I wanted to know what fixed it. The PV didn't do it, then I would have went on to the next item on the list. I guess with a 2t that will be one of my routine maintenance jobs.

Thank you all for your help, much appreciated.

Len.

What did you use to clean the power valve?

[lvermey]

For the most part I used brake clean, dental pick, and a wire wheel in my drill in the places and parts I could, not to much preasure. All the parts appear to be a hardened steel like a valve, so no marks or scratches were left on the parts. The bearings I sprayed with the break clean and wiped off right away. The bearings seemed to be in decent shape. I took the # off them, as well as measured them and will check with the local bearing dealer to see if I can get them cheap. When using the dental tool I was carefull to scrape with the side of the pick and not the direct point.

Hope this answers your quest.

Len.

[lvermey]

One thing I forgot to mention. I could not get the piece inside the exhaust port out. (spiggot) I think it was called. It appeared to be free of carbon when I looked at it with the trouble light, and it moved freely. I did not want to force it. In the instruction it sounded like it should almost fall out.

Any ideas for that.

Len.

[John T]

Not sure, all I can report is that mine is the same, loose and also free of carbon.

Thanks for your help!