Frustrated with my 300ex

[Sjorge450R]

I have been talking about and asking about a rebuild on here for my 300ex for quite some time now. Now there are still a couple of questions.

What bore should I go to?

Will i need a valve job?

Should I replace the valve seals just to be safe?

I am just getting extreamly frustrated with this and i am very confused. And if you could, can you post a list of parts that I will need.
Thanks
Steve

[300exOH]

Originally posted by Sjorge300EX
I have been talking about and asking about a rebuild on here for my 300ex for quite some time now. Now there are still a couple of questions.

What bore should I go to?

Will i need a valve job?

Should I replace the valve seals just to be safe?

I am just getting extreamly frustrated with this and i am very confused. And if you could, can you post a list of parts that I will need.
Thanks
Steve

I would highly recommend talking to an experienced engine builder and purchase the kit from them. They would be able to hook you up with all the right parts. A service manual should explain everything you would need also. Personally I wouldn't attempt the rebuild without one anyhow.

[300exOH]

This thread might help you too

http://www.exriders.com/vbb/showthread.php?s=&postid=1940060#post1940060

[bwamos]

It all depends on what you want, and how much you want to spend.

I would agree with calling up sparks, fst, etc.. and having them work with you to find out what fits you best, in your price range.

297 w/ 11:1, cam and minor port work would be my reccomendation for the best bang for the buck. Filter & pipe required of course if you dont already have a full system.

[Sjorge450R]

i didnt think that sparks dealt with 300ex engines. I will try to call them tomorow if I get a snow day. I tried FST only to findout they are only open from 4-7pm. Does anyone know how much this is going to run me?

[2muchquad]

you dont have to go through an expensive engine builder to get a rebuild.purchase a manual and you could do it yourself once you have your cylinder rebored.$40 or so for it.you can buy those deluxe gaskets kits that come with valve seals etc online for $30 or so.figure $85 for a piston kit if you look around.:)

[Sjorge450R]

i just cant figure out what bore to go to

i think that I am going to go to 1 or mabey two over bore but that is it. Because then i dont want to have to get the cyclinder re-sleeved plus, i already do pretty good on a stock quad with pipe and jet kit. Yeah i found a piston kit for 80 a top end kit for 17 and when i get my boring dong at hetricks, they are going to send me some valve seals.

[sickmojave]

i think that I am going to go to 1 or mabey two over bore but that is it.

The difference between one overbore and two will not give you any noticeable difference in power. if it needs to be bored just go to the next size that will give you a clean cylinder. I think you would get more bang for the buck by going up on the compression ;)

[Sjorge450R]

yeah i think that i am only going to go up one size to clean it up and then go with a 11:1 piston.

[bwamos]

You'll be satisfied with that option, IMHO.

Should cost you about $200 including piston & labor. (Assuming you do the engine teardown yourself, more if you have them do it.)

With the 11:1 piston, you may look at a Web Cam and hardfaced rockers next. Along with an increased rev limit on the CDI. It will really wake her up.

[Sjorge450R]

thanks for all the help. We got about 6 inches of the white stuff coming tonight so I probably wont get to tearing it apart for about 2 weeks but I am going to start ordering parts soon.

[ZeroLogic]

Originally posted by Sjorge300EX
thanks for all the help. We got about 6 inches of the white stuff coming tonight so I probably wont get to tearing it apart for about 2 weeks but I am going to start ordering parts soon.

what state you live in??

were soppose to get about 6 to 10 inches tonite:macho

[bwamos]

We got about 6 inches on the ground here in KC last night also.

[Sjorge450R]

im from pa. Right across the river from trenton. We ended up only getting about 5 - 5 1/2" and most of it turned to water already :( there are still other morons out riding the streets but i dont feel like riding on "wet aspault" thats just stupid.

[ZeroLogic]

i live kinda close to you Sjorge300EX

i live right were ny pa and nj meet together

[rollie]

.80 piston 12.1 comp ratio
.335 web cam
hardend rocker arms...:cool:

worked for me