RE: Thumper Racing 340cc upgrade costs and options?
 

I am happy with my current setup of mods which is no lid, jet kit, slip on, & 300cc. I am done. To me it did the trick. I no longer consider the bike underpowered. That does not mean I can loft the front wheel sky high at will or put the hurt on 450s or even those "Gixxer beating" DRZs. It simply means the bike now has enough power to be ridable & safe on-road & off. By this I mean keeping in front of traffic & climbing hills, both of which I worried about at any other level of mods I had before until I went 300cc. Your expectations may vary so I cant say if youl be satisfied with 300 or not-- I am.

RE: Thumper Racing 340cc upgrade costs and options?
 

Thanks for the info. I'll decide next season if I want to go big bore, since I havent really given the complete mod setup a chance. I havent even been in the dirt yet with my new gearing, nore have I tried adjusting jets to see whats what.

I'm thinking though that I will be outgrowing the bike completely no matter what I do to it. I see orange and black in the future, but how long is a different story. Like I said i just want to be able to lift the tire through deep puddles and over logs or whatever, and be able to climb longer steeper hills. I was discouraged that my bike quit on me on a hillclimb, after doing the jetting andthe exhaust. Not looking to do wheelies for several blocks.

We'll see what summer brings next year. Too bad theres only about a month or so left of riding [:'(]

RE: Thumper Racing 340cc upgrade costs and options?
 

"We had a sleeved 340 from thumper racing and had bore problems, ring problems, etc."

http://www.thumpertalk.com/forum/sho...19#post5271719

That's part of a post from Bill P. at Thumper Talk, who regularly rides at Moab. You might want to ask him about specifics, but according to his experience, he prefers a plated cylinder over sleeves.

RE: Thumper Racing 340cc upgrade costs and options?
 

Personaly my bike does all this stock.

RE: Thumper Racing 340cc upgrade costs and options?
 

Yes, but you guys drive on the wrong side of the road and I think your speed would be negative since you are below the equator. :D

RE: Thumper Racing 340cc upgrade costs and options?
 

That's very helpful information. I'm still debating whether the extra 31cc will really make that much of a difference.

RE: Thumper Racing 340cc upgrade costs and options?
 

I plan on hopefully next year getting the 331cc upgrade. I was thinking really hard on a new bike, even a kx450f. But now even some new jetting (128), better gearing, 14/48, and a Big Gun, I'm already thinking this bike is not so bad. It's got much much better response, more fun. My needs are satisfied for this season. So another $800 to make it a 331cc and maby a pumper carb after that... and probably a large tank eventually, and I'll be much much happy.
Can't wait. Now I just gutta get the bills straightened out

RE: Thumper Racing 340cc upgrade costs and options?
 

Tremor, I've heard the same comments on the 340 kit several other places as well. I'm starting to wonder if I wasted $100 on my used KLX300 cylinder. I was going to have Bill Blue bore it and sleeve it (there is a chunk missing from the case insert, no plate job for me) but if the sleeved setups are only getting 8000 miles (I don't know what TR uses for their pistons and rings but it sounds kinda poor) I'm thinking of ordering the bolt on kit from Kustom Kraft. Marvin replied to me within hours of me sending an e-mail to him:

Quote:

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Joshua,
We have done a lot of these kits for the 250S. We bore a 300 cylinder and re-Nikasil them. We also use a JE 83mm piston. This combination has proven to be very reliable and I would expect the longevity to be increased over the stock set up based on the high quality of the piston. A Nikasil coated bore will last an extremely long time with proper lubrication, jetting, and air filter maintenance. By nature the rings wear because the coating is so durable. I would replace the rings and piston according to the manufactures recommendations for years of trouble free riding. If you have any more questions please feel free to ask, and I look forward to helping you out.
Thanks,
Marvin Claridge
PS. There is a review of a project KLX250S with our kit in the current issue of Adventure Motorcycle Dual Sport News. You should be able to contact them through www.dualsportnews.com

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RE: Thumper Racing 340cc upgrade costs and options?
 

Did you see their pricewhen you send them the KLX300 cylinder? They do it for $440.00. The price for the KLX250 Kit is $769.00. That's a big difference even when you consider shipping, isn't it?
http://kustom-kraft.com/klx300bb.html

RE: Thumper Racing 340cc upgrade costs and options?
 

The price difference accounts for them buying a new 300 cylinder to work on. The one I have I bought from a blown up bike and the piston tore a chunk out of the neck that drops into the lower case. Bill Blue or TR can use it to sleeve because that neck is removed anyway but I can't send it to KK to have bored and coated because the damage is too severe.

http://i88.photobucket.com/albums/k1...3/DSC01530.jpg


I still may send it to Bill anyway, he's done a bunch of them and everyone is happy with them.