LA Sleeve DRZ 450 big bore kit

[PeteN]

I have a couple weekends of time on my 2000 DRZ400E with the big bore kit now and I am quite pleased. It was a pretty simple mod as far as engine mods go, no case opening. It gives a big midrange/low end boost and a little more top. It is a 96mm piston (actually 453cc), only 1mm smaller than the thumper 470 kit(actually 463cc), but keeps the stock 12.2:1 compression ratio instead of 11:1 like the Thumper. It is a JE piston and uses the same Cometic gasket as the Thumper (97mm).

In the trails it creates wheels spin much more than stock, but I have a pretty worn tire right now. I haven't noticed any more vibration than stock. The jetting is 50 pilot 2.5 turns out, EKP needle 2nd clip, and 165 main, seems pretty close. I raced a 1/2 mile flat track and it didn't feel much faster, but I could almost keep up with some of the Rotaxs?!? I think it will help more on a track with greater speed changes, I'm racing a SuperTT this weekend so we'll see. :) :aj: :)

 

[Rich Rohrich]

Thanks for the update Pete. I'm really interested to here how it works in an acceleration intensive venue like a SuperTT race.

Does this kit use a steel sleeve or a re-plated stock barrel?

 

[PeteN]

It's a steel sleeve and I had some problems on the install. They put it in 90 degrees off and then heated it and turned it. It must have slid up because when I first ran it, the sleeve dropped .003", the head gasket blew, and it started pressurizing the cooling system. They pressed it back down and milled one more time and so far it seems OK. I was wishing I hadn't done it, but now I'm glad. ;)

 

[DualSportr]

have you re-geared it at all? I never seem to notice a horsepower increase from more bore/stroke until I gear the thing up a bit.

 

[PeteN]

I'm running 14/46 in the woods, which is one tooth down on the back. Unfortunately, my rear tire was pretty worn, so all I got in the woods was tire spin. I think I will get a better feel for the power this weekend in the SuperTT, there is a lot of acceleration an the midrange boost should be great. ;)

 

[CAL]

Wow! 14/46 in the woods!? I hope those are some open woods. I ran 13/47 on my E in the woods. I couldn't even stand the stock 14/47. I'm running 13/49 on my 426...of course it doesn't have the wide ratio first gear though.

 

[PeteN]

13/47?? You must like to take in the scenery?!? ;)

 

[CAL]

Originally posted by PeteN
13/47?? You must like to take in the scenery?!? ;)

I'll be the first to admit...I ain't no Randy Hawkins! :moon: