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Eric Gorr YZ300 arrives! Small ride report added

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Guys, I was not goign to say anything about this until I had it installed. Once I saw it, I just could not wait.

I have to show you the before and after as its pretty funny. Before is easy to spot. It was thrashed. Still a decent value even though I did have to buy a new powervalve for it. It is better than changing a good 250 cylinder.

Obviously, the second pic is Erics work.....LOL I dont know if the picture will do it justice. Its the same color as an 06 stock cylinder, now. You can see that a ton of work has been done to all of the ports. They are semi-smooth, and sharp on the edges. Slightly scary looking as I can see this will make some serious power. I've seen the work the other companies turn out and this looks much better.

I also took a picture of the damaged powervalve. I dont know if this is normal or not. The cylinder I bought was a 2003 and appeared to have quite a bit of run time on it.

YZ2501803Engine011.jpg

4510 047.jpg

4510 048.jpg

4510 049.jpg

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I was just going to ask for a size comparison when I read the title, but I see that you put your old piston in the new cylinder already and took a pic!!!

Awesome, that piston looks quite a bit bigger. Did he have to drill and retap new holes for the bolt shafts?

I don't see a groove for the o-rings anymore, that's why I asked, but what do you use now for a gasket???

What kind of porting did you go with?

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The cylinder studs and dowels are in the stock position. The o ring grooves are gone. No more trying to hold them in the grooves! The kit uses a flat, metal head gasket.

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Eric did confirm this is a common problem with the powervalves. Probably not a bad item to replace every now and again, but they are VERY proud of it!

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Looks like you have to run a traditional head gasket as opposed to O rings.. :thumbsup: And ya, Ive had two PV's come out of my cylinder looking just like that.. One on my 285 and one on my 250... :lol: Oh well, such as life I suppose..

Congrats RC, you'll love it..

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I JUST won a beat jug and head on ebay a second ago for a total of 100bux! please let me know what the turn time and final $$ was. a pm is fine. I did not see the 300 in the site. I am ready to go big on the rebuild bike!

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Does he adjust squish as well for you with the kit?

Do you need to take a reading with the solder wire before you send it out, or can squish be measured with just the jug, piston, and head?

I'm guessing that squish is determined by the length of the crank shaft shafts in comparison with the head and jug? does that make any sense?

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the squish is the distance between the piston crown and the tightest portion of the head. you and I would use solder to measure, I would assume eric has done enough that he can go off of measurements in his notes.....assuming your rod bearings are tight

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If that's the case, then why do we need to take measurements all the time? I have a feeling that it's not just rod bearing play, but maybe small discrepancies in castings for the case?

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the kit does not use the stock cut on the head, it is cut. therefore the stock flaws are thrown out. should be able to pull a measurement from a ref mark......if you have notes on where and how much.......us common folk use solder

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I was thinking the same way that Brentn was. I was thinking it was from all the variables with heads cut, rods being slightly different and cranks not 100% true. Being a 300 kit I would think that E Gorr since he developed it would just be able to mill all heads the same and probably be almost right on with them

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I JUST won a beat jug and head on ebay a second ago for a total of 100bux! please let me know what the turn time and final $$ was. a pm is fine. I did not see the 300 in the site. I am ready to go big on the rebuild bike!

Turn around time all depends on how busy he is. He said he gets really busy around Feb. due to all of the work he gets for the amateur series. My turn around was 2 weeks and $600.

MAX!!!

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Does he adjust squish as well for you with the kit?

Do you need to take a reading with the solder wire before you send it out, or can squish be measured with just the jug, piston, and head?

I'm guessing that squish is determined by the length of the crank shaft shafts in comparison with the head and jug? does that make any sense?

the squish is the distance between the piston crown and the tightest portion of the head. you and I would use solder to measure, I would assume eric has done enough that he can go off of measurements in his notes.....assuming your rod bearings are tight
If that's the case, then why do we need to take measurements all the time? I have a feeling that it's not just rod bearing play, but maybe small discrepancies in castings for the case?
the kit does not use the stock cut on the head, it is cut. therefore the stock flaws are thrown out. should be able to pull a measurement from a ref mark......if you have notes on where and how much.......us common folk use solder
I was thinking the same way that Brentn was. I was thinking it was from all the variables with heads cut, rods being slightly different and cranks not 100% true. Being a 300 kit I would think that E Gorr since he developed it would just be able to mill all heads the same and probably be almost right on with them

Eric adjusts the squish, you do not need to give him any measurements.

MAX!!!

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