EC300 still down on power

[rpduc]

Good luck with the seals. Hope that fixes it.
I just read thru all six pages of this and I didn't see where anyone answered your question about compression... Maybe i missed it.

I just did a compression test (prelude to rebuild) on my MC 250 with 3 yr. old piston, rings, lunched right main, very questionable big and little end bearings and I got 150 psi without oil, 165 with some WD 40 shot in there. I've seen GMP comment that he is in the +190psi range so seems like your compression is pretty low to me. Of course as Stainless mentioned there's always that nagging doubt about accuracy of compresion testers, mine included...

One thing I noticed on mine was that the bushing that runs inside the right main seal had a wear groove in it. (at least I'm pretty sure it's a wear groove, but this is the first time I've been in there and I have not seen a new bushing so not absolutely sure....) I overlooked that when ordering parts and put back the old bushing but I'm having second thoughts... At 46 bucks kinda spendy but beats eating up another main seal. Also note which way the bevel on that bushing faces upon disassembly...

And having just been in there I can confirm that you could replace the right seal thru right cover. Heck you can even do it without draining the oil if you lay the bike on it's left side. Just don't lay it on the shift lever or it will push the shift shaft thru and possibly disengage the shift ratchet.

Oh yeah, and I've been reading up on static timing and in your stator pic that plate on the 2 o-clock bolt is the locator plate that indexes the stock timing so I believe your timing is "stock" for that ignition.

http://www.gasgasrider.org/forum/showthread.php?t=4604&highlight=Static+timing

 

[GMP]

Yes, a sound 250 with RBD head mod max comp for pump gas is in the 190 - 200 PSI range. My '07 is still in there. My new stock '12 250 with 12 hrs on it is 180 PSI. My comp gauge is accurate, checked out against a gauge in the lab at work.

 

[LAWMAN]

GMP's post w/compression #s might make a good sticky

 

[19brendan81]

Thanks for the input everyone. Crank seals diem.t change anything. I was at a loss to explain what was going on when a saw an 05 300 for sale in my city. The seller was a good bloke and let me take it for a test ride to compare it with mine. I can tell you all that my bike goes heaps harder than this stock 05 did. Leading me to believe there is noting wrong with my bike at all.

unfortunately, at the end of test riding my bike i washed out the front wheel and folded my leg in half at the knee. Im writing this from my couch with a big bag of ice on said knee. I suspect i have torn my acl again. Will see doctors during the week. Its a cruel sport dirt biking.

 

[hannesd]

Thanks for the input everyone. Crank seals diem.t change anything. I was at a loss to explain what was going on when a saw an 05 300 for sale in my city. The seller was a good bloke and let me take it for a test ride to compare it with mine. I can tell you all that my bike goes heaps harder than this stock 05 did. Leading me to believe there is noting wrong with my bike at all.

unfortunately, at the end of test riding my bike i washed out the front wheel and folded my leg in half at the knee. Im writing this from my couch with a big bag of ice on said knee. I suspect i have torn my acl again. Will see doctors during the week. Its a cruel sport dirt biking.

those test ride hey... i twisted my foot last week on a first test ride after a new impeller and seals and bearing.
2 upcoming rides are cancelled too
it all happens so stupid...oh well, you can't get hurt if you don't do anything

ciao, Hannes.