Suzuki DRZ400 Rebuild Restore Modify thread.

Well after I got all our baby bills paid off I picked up another project.
I'm secretly building this to get one of my best friends into dirt biking so I'm rebuilding it on a budget so he can get into a cheap and reliable bike for very little money.

This is a 2002 Suzuki DRZ400E
So it has kickstart and electric start but not all the emissions and street legal stuff as the "S."
It also has the better carb, the flat CR or FCR carb by Keihen.
It's been street legaled with a Tusk enduro lighting kit. It also came with a K&N reusable air filter.



So first things first:
Oil change and air filter service: wasn't very dirty at all. The previous owner was a girl who rode it on the street to and from college.

I totally hate the stock DRZ headlight so on goes a Polisport headlight.


It did not have the stock cable driven speedo so a Trail Tech endurance computer and a used Scott's Stabilizer is next.


It already had a nearly new Pro Motion O-Ring chain and sprocket set so that got a deep clean and oiling and stayed.


I tried valiantly to revive the battery,


but it was toast so a new one went in. (Also: who zipties in a battery? Well apparently the former owner lost the stock tie down so they thought these skinny ones would work).




Next I checked the valves and timing chain. I was pleasantly surprised to find them in pretty nearly perfect so I didn't even have to mess with them. (If I remember right .200 intake and .300 exhaust).

It also appears to not have an autodecompression intake cam (I did some research and I guess this is a good thing as the auto decompression cams tend to fail on these bikes).

The left radiator was looking pretty sad so I yanked the tank to take care of it.


I'm getting pretty good a straightening these:




And I found this backyard radiator hose situation some previous owner had cooked up...



Yup that's a red garden hose with heat sleeve over it...



and the exhaust was touching the hose to the water pump...



so I ordered new hoses.

Header pipe before:



Cleaned:


and After:

Next:
The seat cover was garbage.


So I re upholstered it.



Then out came the carb for a rebuild:


I noticed at this point the remote idle adjust screw assembly was missing (it allows you to adjust the idle while the carb is in situ on the bike.
So I measured the idle screw and ordered a new assembly.


Here are some boring jetting pictures fore me to remember what jets are in it.

45 idle


135 main (I could probably go up to a 145).


leak


and new float bowl gasket (thanks Suzuki for a $27 gasket....)

and of course it was missing a hose clamp from the air boot to the carb.


And the front tire was worn out: so I got a new one on there.

Grips were garbage.


New Fly racing grips (I'm a little undecided on these... they're a little hard for my liking).


And I got a new clutch lever too. ($15 Moose). (Strangely this took a little modifying with a file to make the clutch pull correct).

Very nice Stratton! Those jets look hammered!

Thanks. Yeah those jets definitely have been taken out a few times with the wrong screw driver lol.

Also the bike has protaper bars and an aftermarket Scott's shifter too.

It's all finished up now for the most part. I'll post some completed pics later.

I think it's missing 17" wheels, and slicks....

Tonkaman said:

I think it's missing 17" wheels, and slicks....

Click to expand...

Actively searching KSL and eBay!


Here are some completed shots. It cleaned up really nice!
I buffed the tank and front fender with some 1500 grit wet paper and it took out all the little scratches that had collected dirt and made the tank look brown on the sides.


(the white on the radiator shrouds is sun reflection).

Cool! Looks like a fun project

Gravy said:

(thanks Suzuki for a $27 gasket....)

Click to expand...

I hear ya. A friend of mine spent ~$100 on a couple gaskets/o-rings on his dual carb XR600 that I was rebuilding a few years ago

Sudco rocks for Keihin and Mikuni carb parts: http://sudco.com/carburetors.html

Finally got a minute to swap rear tires.

(Thanks for the good used one Tyson!)

Sometime in the bike's previous life the airbox snorkel was removed, so I went up on the main jet from a 135 to a 145 and now it doesn't want to idle as slow as I'd like (which should have no bearing on idle). So I had the carb ultrasonically cleaned (which is so great btw) and it still isn't quite right so I bought a remote fuel screw (currently at 2 turns out from bottom) so I can mess with that while the bike is running and a few different idle jets (stock is 45). I'm going to try to tune it a little better today. It's probably fine for most people, but I'm kind of particular and it's been a learning experience on jetting.

[video=youtube;SKn7y1QHA1c]https://www.youtube.com/watch?v=SKn7y1QHA1c[/video]

Looks like it's running like you need it to. Wish mine was doing the same! I'm jealous of your electric start, for sure. These DRZ's really are great, do everything bikes.

So I found that someone had put a mikuni 62.5 slow jet in this bike instead of the correct keihin one which was causing the problem. Stock is a 65, renegade only had a 70 and a 55 so I got the 70 keihin in there and it started first stab at the starter and idled well so that was the fix. My friend just left with it for its new life in Idaho.
That was a fun bike!

Already gone? Dang that was fast!

What's the physical difference between the mikuni Jet and the Keihin jet?

Tonkaman said:

Already gone? Dang that was fast!

What's the physical difference between the mikuni Jet and the Keihin jet?

Click to expand...

Thanks, it was a good bike for a minute

Well it's a Keihin carb so Keihin jets are what it should run.

Here's how you identify the brands.
Mikuni mark


Keihin mark


This is what I learned today from the carb tuning guru at Renegade today:
Although a Mikuni Jet will physically fit in the starter jet spot; the taper into and out of the bore is different and the number (for example: 65) is just a place holder and isn't necessarily quantifiable.
So a 65 Mikuni might not have the same bore as a 65 Keihen

You'd need a pin gauge or carb jet gauge to accurately measure the size of the ID


It would be really cool if a 65 meant .65mm I.D. , but alas it doesn't.