improving suza DRZ400SM

[DEAN]

here is the list "to do" in winter with suza DRZ400SM-2005

1. FMF Powercore 4 muffler (have at hand)
2. FMF hi-flo header pipe - ??
3. FMF Jet kit for SM - ordered
4. K&N air filter - ?? (maybe other manufacturer?)
5. stock airbox modification
6. Hotcam stage1 intake cam - ?? (maybe other manufacturer?)
7. 39teeth rear sprocket - ?? (where to find it?)

sign "??" means i'm not sure if I need it. I'd like to hear good piece of advice from people who alredy did it and "got the power".

pls look at this list with critical wiew and write your opinion.

Thanks a lot

[Muzzard]

Hi Dean,
Mate there are several blokes on here with DRZ's that are good bikes. Neil is the obvious one to listen to as he has just done a lot of mods to his bike including the big bore 436cc kit.
The models vary greatly by specification country to country so if you can cut and paste the Factory Specifications for the European model you have, we will be in a better position to advise you, OK? ;)

[DEAN]

Hi Dean,
you can cut and paste the Factory Specifications for the European model you have, we will be in a better position to advise you, OK? ;)
mine is japanese model with fat silencer (foto)
I didn't heard about restricters or engine mods for different countries.

http://www.motodata.ru/trash/drz-right.jpg

[Muzzard]

Nice picture Dean!
You have a bit of skill by the way you are grounding that DRZ mate!
You will make Neil proud :lol:

Yes mate there are several different specifications out of the Factory depending on where you are, you get one that goes, or one that goes... but not as fast or hard...

There is a difference in the timing, carburettor is different, airbox, exhaust and no doubt a few more things too.
Neil will have the good oil for you regards the specs for here vs. there... ;)

You have a muffler to fit already I see and a few other things on your list.
Is your bike fitted with a Keihin Carburettor?

[Wobbly]

Nice pic dean, looks like you can ride! (bastard! :lol2: )

Ok, here's the biz ... the DRZ-SM is based on the DRZ-S, which is a slightly down-spec version of the enduro, the DRZ-E. The differences are basically lower compresssion ratio by way of a thicker base gasket, milder cams, lower rev limit (think the ignition curves are the same tho) and a Mikuni CV carb.

Firstly, exhaust - a slip on is worth no more than a gutted original apart from being quite a bit lighter. If you want more hp you need something with a tapered header, such as the full FMF system or the Yoshi or Muzzy. I think with the FMF that you can buy the header separately later though, but I'd just go for the full thing right from the off, so take the question marks off that item ;)

Next thing to do is to do the airbox mod - cheap and easy, just hack out the top of it. You can also hack the sides, but this doesn't really do a lot except make some near rorty airbox noises :) (as the restriction seems to be in the inlet tract, according to burned on TT)

The next stage of mods require opening up the motor. If you're going to take the cams out then I'd look at doing the base gasket although it's a little more work. You will most likely need to pull the head off too, which means a new head gasket. Pull the head and cylinder off and just swap in the std DRZ-E base gasket which comes straight from the suzi catalogue. This step probably depends on how comfortable you are with refitting the piston into the barrel, which is still very easy to do, but a bit fiddly if you haven't done it before.

Finally, cams. Don't worry about any poofy stage 1 anything, get the most aggressive cams you can, which should be the hotcams stage 2 cams. I've got the old hotcams which are the same as the current stage 2 cams, both inlet and exhaust. The inlet gives you more bottom end, the exhaust opens up the top end so it carrys on rather than running into the brick wall you no doubt currently feel. The exhaust cam is ace :up: Some people say it drops a bit off the bottom, but with both cams and the 436cc kit I only noticed more power everywhere :)

Here's a thread with some detail on the rebuild I did a while back - the bike has about 140 hours on it now since then with no problems :up:

http://www.vsmr.net/modules.php?name=Forums&file=viewtopic&t=325