Here ya go Service Yamaha YZ300

[yathump]

http://www.servicehonda.com/yamaha-2010-models/yz300

, not badly priced considering that the dealers are not budgeing much off of MSRP

[adam728]

What's so special? It's $609 over MSRP, and the only thing done is an Eric Gorr big bore kit, which anyone can buy. All the "customizing" is suspension stuff that anyone can also have done.

I'm just saying, there's no custom fabrication or anything. It doesn't really excite me, because I could make my 05 just like that bike.

[8675309]

:thumbsdn:looks like $2k for a cylinder and some graphics to me

[7thirtyseven]

Wow!!!

[brentn]

I was going to say the same thing, there is nothing really different about that bike other than the big bore kit and some stickers...

wth?

[i ride]

it says it has a set of showa forks and a showa shock. doesn't look like it to me.

[adam728]

it says it has a set of showa forks and a showa shock. doesn't look like it to me.

Also says it has a Mikuni TMX flat slide carb.

I think someone copied a table over, and didn't bother changing much in it.

[Budlite]

My guess is that it's not a 285 either. It's probably a 295 but which one ?

[phil-coley]

funny how things get changed in a short space of time ,i remember a few months back that they were puting a 250 yz motor in a 4 stroke frame for 2010. dont you just love these special bike builders,truly years ahead of us. phily cee still laughing.

[harrperf]

Why would they say a 285 and sell a 295??? Just wondering.

Not to mention, there is a reason 285 seems to be the limit in bore size, ever looked at the casting on the cylinder? Not really much room beyond a 285

I could be wrong, and would hope it's not "just a 285" but from my knowledge and from what it says...285 sounds right to me.

[busted bones]

I thought they said it would be the 295 kit? And also it seems like everything listed there is wrong

[adam728]

All the original media on this bike was saying it would be a 295. Must not have turned out reliable enough.

As for it being in a 2010 250F frame, I've only heard that rumor here, and cannot think of one good reason they'd do that.

[NE14MX]

I've been doing a little research on this.

The Service 'Yamaha' bike has the Eric Gorr 295 kit installed. He can port it for enduro or mx use. The 295 kit is available for 2000-2010 YZ250's for about $600 through Eric's site Eric-Gorr.com. Eric expects to sell many more of the kits to current YZ owners than complete bikes.

Service Honda recently picked up franchises for other brands and this is there first venture in that direction.

The Gorr kit bores out the cylinder beyond the oring seal, plates it and replaces it with a custom head gasket. That's how it can be 295. The mx version is supposed to top 53 hp. and be competitive with any 450 four stroke but you can have the power taylored to you (low mid high) through his porting. He has a special piston that weighs the same as the stocker so no crank balancing is required.

From what I understand the FMF gnarly or stock pipe are the best choices for enduro versions. It's still debatable what pipe works best for MX. A custom 295 pipe would be sweet. Getting the jetting right is probably the trickest part of the conversion. It would be best to start rich and work down so as not to squeek the cylinder.

Oh one more thing. Eric resets the squish band on the head to get rid of the detonation. Also he can set it up to use pump high test or race gas.

Edited December 17, 2009 by NE14MX
additional information

[cryzrider]

With the 285 kit the inner O-ring is very close and I recently had mine leak into the cylinder forcing me to slap the 250 top end back on. I do plan on putting the 285 jug on a crazy CR aluminum framed YZ Frankenstein bike that I'm rolling along on. I'm thinking about a new dirt bike next year and of course a new YZ is in the list but I'm also not ruling out the TM 300, Gas Gas 300 or the Husky.

Craigus

[mliebal]

I see from Eric's website that they do case mods as well on this kit for the yz's.

So, one should send the whole engine for upgrade?

I dont know, I am not too excited about sending the whole engine.

Anyne know for certain how much the case mods add to the perfromance?

Mike

06 YZ250

[NE14MX]

I don't see where it says the 250 mod requires the cases to be sent. I do see it on the 125 to 144 packages. I thought I saw somewhere (search for yz300 on tt) that the model years 2000-2010 were specifically picked so that case mods were not required.

I have a '93 with the long rod kit so I'm out of luck for this mod. It does have me thinking about picking up a 2006 or 2007 and having it done for mx though. Sounds sweet. If anyone has done this with the mx mod, please give us a review.

[mliebal]

My bad. I was looking at the order form.

The section showing the big bore kits, said case porting included for YZ and RM, but did not state for 144 bores.

Good!

[RCannon]

AJ told me personally he was going to put the yz 250 engine into the 4 stroke frame, obviously he did not do that with this specific model.

Service spends way more time building project bikes than they do updating internet info. It makes it very hard to know whats going on if you dont live down the street from them.

[Bambislayer]

Service Honda recently picked up franchises for other brands and this is there first venture in that direction.

No its not. AJ built a KX500AF some time ago.

[sdjclevland]

I saw this the other day and was wondering why does the yamaha look like the least was put into it?

That kx looks awsome and it says it has support from kawasaki and so does the honda.

Also if both these companies dont make 2 strokes anymore where are they geetting these motors and why are they only making a 500? i dont get it