Big-Bore Kit?

Which big-bore kit is best for the DRZ400?

I probably will get one later this year (when gets too cold to ride again), and would like to know who makes the best one, and what sizes are available?

Of course, along with the big-bore, I'll probably get the E pumper carb, airbox mod, cams, and some kind of performance (but not loud) exhaust.

Not racing -- just like to ride a high-performance street thumper.

Best and the only way I would go (actually I already did it) is MelleniumTechnologies http://www.mt-llc.com/flash.shtml

The one I did is the 436cc was 450$ for all the labour and parts (piston,clips,pin,gaskets "E" model base gasket so you bump up your compression as well rings.....)

They have another,bigger bores but they require a sleeve I believe and cost 750$ :naughty:

How is the low end on the 436 kit?

How about reliability compared to the stock?

I've read the reliability on the 436 is on par with the stock stuff. The 450 is relatively new, so it's hard to tell about the long term reliability. I have the 450 and I think Jshur does, too. It runs like a champ now. Burned was a little concerned about how close the cylinder wall gets to the cooling jacket when they bore it out that much.

Best and the only way I would go (actually I already did it) is MelleniumTechnologies http://www.mt-llc.com/flash.shtml

The one I did is the 436cc was 450$ for all the labour and parts (piston,clips,pin,gaskets "E" model base gasket so you bump up your compression as well rings.....)

Did you get that done at Mellenium? I would like to put that on my bike eventually.

Thats exactly what I did, millenium. :naughty:

You have a number of options. You need to pick the one that will give you the best service and performance.

There is a lot you can do with the stock displacement with a number of performance mods. It will stress the engine more, but the DRZ seems to be up to the punishment.

Bigger displacement is great too, but if you are going to run in the upper RPM range most of the time on the street it may not be your best option. It typically gives you more bottom and mid power performance increase.

For the street - cams, combustion chamber mods, higher compression pistons, carburation (Lectron, Eddlebrock, etc.), high flow exhaust, etc. can make a lot of HP from the stock displacement. A friend of mine did this with a stock displacement S and it hauls on the street.

Don't forget about the bottom end, clutch and transmission. They are going to take more abuse. Cleaning up/blue printing them will benefit performance also. Better clutch plates and heavy duty clutch springs should also be looked at. If you have the cash there are a couple of aftermarket clutch baskets that will help with performance and shifting.

I started 3 new magazines subscriptions in magazines focused on the type of riding that I do for background and review. I made phone calls to all of the kit manufacturers that I could find and compared their recommendations with what my objectives were and their competitors. You'll learn a lot.

Good luck.

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