I am millimeters from pulling the trigger on the big bore kit. One concern is how the cylinder head cuts into the water jackets on the 351. I've also noticed that Bill makes a 340 kit. Would this be a "safer" option, since you would leave more of water jackets intact?

Big Bore kit = drool

 

Go big or go home.


I always have this thought process for motor toys:
Is the motor as big as it can be? No? Make it bigger.
Is it as fast as it can be? No? Make it faster
Is it as fun as it could be? No? Make it more fun.

I do the same thing with my cars.. NEVER buy the base model when there's another model with a bigger motor, or an added turbo, or something. What's the point!

 

Damn, I've been owned! lol

 

hahaa, just trying to show you the light.

Even with the tiny bit smaller waterjackets, still never had the bike overheat. The fan doesn't even come on more than it did when stock.

And I've had it putting in the woods on 90° days for hours and hours. I overheated, the bike did not

 

Man, I do want to go 351! I've been riding tight, technical Washington state trails and I need some instant wheel lofting power. My concern was from a post by Buffalony, he had an issue with the 351 being a bit tight on the water jackets. It seemed like a reasonable concern. A 340 would be a good compromise between cylinder walls and power. From all the posts I've searched everyone is happy with the 351 kit. I just want to be sure before I drop th' cash on hardware and mechanic.


Big Thanks!

 

Don't pay a mechanic!! It's a pretty easy job if you know how to read a manual and turn some wrenches.

 

My thought on 351 is only an opinion.. Look at the pictures that bake posted.

I never had the 351 kit so I cant say with evidence that it will overheat if you flog it for extended periods of time. Honestly the only way to get scientific proof on its future reliability would be to take a stock bike and 351 bike, put it in the hands of the same rider and beat the crap out of them both until one or both of them failed. Granted you would want the same person to setup both bikes so you would eliminate all variables. You would also need to ride them on the same track/course/trail.

The difference between the 340 and the 351 is only 11cc's. your talking about a milimeters of cutting material. Like I said earlier there are several people on here to include an individual that tested on of the first bikes that say there are no worries... So dont worry about it... Either way the 331, 340, or 351 will be a great choice and you wont regret it.

 

Cool, I appreciate the reply. *salute*


Pressing the big bore button RARRRR!!!! Hulk Big Bore Smash!

 

has anyone had it ported

 

Being one of the first on here to big bore the KLX, we did not have a lot of options back in the day. First, I went with the 300cc using Kawasaki parts. That was nice. I then did the 331cc (Kustom Kraft). It was great, I loved it. I then did the FCR 35mm carburetor set up by Jerry Leighton. That was even more wholesome goodness and complemented the bigger displacement like vanilla ice cream does warm apple pie. Then I did fork springs, and then sold her for my current KTM.

If I was starting over with a new KLX today, I would go straight for Bill's 351 kit, and another FCR35 carburetor. And while the bike was down for that service, I'd be having the suspension revalved and springs replaced with those for my weight and riding style by a good suspension shop. Toss on a nice full-system exhaust and open up the airbox. Those mods would transform the KLX from an anemic rocking horse into a respectable dirt bike that would keep even the most serious riders happy for a long time to come. That all would probably set you back in the ball park of around $1500 or so. But in the long run it will save you money as you nickel and dime your mods trying to find a silver bullet to give you the bike you want only to sink a bunch of money into relatively ineffective mods stuff. The only true way to do it right is to start with the basics - suspension, displacement, intakes, and exhaust. So my advice is don't screw around, go straight for the jugular and get serious results with serious mods.