I hate to say this but a stock 400ex with minimal work can blow away a ds 650. i know a guy that has a 650 on NO2 and its still slow. I dont know where the 50 stock hp is???????????????????????? It certainly does not make it to the ground. And I'm not discrediting CT, because tehy build good stuff. I think TC is going to be your best bet.

 

Why Don't you call around and see what different setups are available from each of them. Cost is a big factor for me although it might not be for you. The question you ask about who is best will certainly make tempers flare as that really is a matter of opinion whether it depends on How many championships a certain name has won or how fast your buddy's bike by so and so is. They are probably all pretty decent or they wouldn't be in business long. See who will give you what you want for what you can afford and how long that will take.

CT250R

 

Who's the best 4-Stroke engine builder?

It depends on what you're using the quad for, and what you want out of it. If you're looking for the ultimate race engine, and you're not as interested in reliability, check out TC or Sparks. If you're looking for something that's fast on the trails, and still stands up to years of punishment, check out Powroll.

As far as anyone else goes -- everyone seems to be getting into the thumper business lately -- all the two stroke companies are touting new products for the 400EX. Would I consider them four stroke engine BUILDERS? Not as much as the three I just mentioned.

Another thing to think about is some of the four stroke companies who only work on quads have only been dealing with this engine for a few years, where the companies who also do dirt bikes have been working on it since 1994 (when the XR400 came out). These companies probably have more options for you.

Make sure you have a good idea of your goals when you talk to any company. It's more important to decide what YOU want out of your engine, then find a company to provide it, rather than go by advertising claims and pumped up horsepower numbers.

 

Well said Pam, I agree with you 100%