"Trikenstine"

[Storyboy]

I have a 1985 honda 250es big red. I'm trying to get the most power out of it as possible. Would the top end off a 300 fourtrax bolt up? I kno the design is almost exact, but is there any diffrence?

[TheRealFatShady]

The difference is the stroke of the crank. The bore is the same on both, in fact, the head and cylinder is the same. Supposedly the 1988 trx 300 cam is better slightly, but I doubt it's by much.

It depends on how intense you're wanting to go, and how much you'll spend. There are ways to improve it, but from what I gather, the you can put a lot into the SX/ES and not get much in return. I believe Dirtcrasher did that with his.

You can put a full 2wd TRX300 engine in, but you'll have to swap the output shaft which requires pulling the side cover and clutch.

[Storyboy]

Why would I have to change the output shaft?

[thestud25]

Why would I have to change the output shaft?

It is not the right link to line up.

[Storyboy]

O ok. So what could I do to get more power out of it?

[yaegerb]

O ok. So what could I do to get more power out of it?

Sell it and buy a 250r

[Storyboy]

Sell it and buy a 250r

Lmao! You funny. 250r aint turning 27" outlaws. I said power, not speed.

[briano]

2wheel drive trx 300 engine with a big bore kit, cam, carb, and pipe. Now all you need is the skills to do it.

[Storyboy]

I got the skills

[hoosierlogger]

In my best Thorny voice from Super Troopers..... DO IT!

[TheRealFatShady]

Or trx300 engine with trx 350d crank and top end (same top end as 350x), but requires custom made reverse grind cam as the motors run opposite ways. Flywheel side of the 350 crank is better, but can have it turned down or one guy I know of made a flywheel out of the two (inner section was from the 350) but it was slightly off and never ran as strong as it could have.