I Recently removed my flywheel and had 7.06oz taken off. Jim at LC Machine told me that he didn't think there was any way that he could safley remove any more off of the flywheel's sholder. This is not to say that it cannot be done because there are records of people having removed more than 7.06oz. I thought I would post a how to for anyone interested...

REMOVAl

Step 1. First off you should place something under your Z to catch any oil. Some guys like to elevate the left side which will cause the oil to run away from the flywheel in return causing less of a loss of oil during the procedure. Another thing i've herd is to let the wheeler run for a couple minutes to allow the oil to leave the base of the engine. Start by removing the case saver by taking out these two 8mm bolts


Step 2. Now remove the Cover to the starter gear by taking out the three 8mm bolts,
but be careful not to lose the washers.



Step 3. Now Remove the eight 8mm bolts which hold the cover on, then remove the cover and
carefully set it on the foot peg as it holds your stator.



Step 4. Place a 27mm offset wrench or cresent (i used a cresent) on the back nut (Red arrow) and a 17mm
socket on the front one (yellow arrow), breaking it free. Set the nut aside for now.


Step 5. You can wait to remove these allen head bolts which hold the actual flywheel gear on
or remove them now. I chose to do it now by placing a socket on the nut to hold the
engine from rotating while i backed out the 6 allens.


Step 6. Now your ready to pull the flywheel. I can only explain this step because I don't
have a puller, instead I loaded the girl up and took her to a local dealer. They
charged me 15.00 flat to use the puller. Anyhow you simply put the puller over the
end of the crank and begin tightening the puller in return pulls the flywheel off
its tapered shaft.


Now your ready to take the flywheel to your local machine shop for machineing...

This is what it will look like when you get it back, before on the right and after on the left. (The following photo is property of Z400Clone because I never snapped any photos of mine)


INSTALLATION

Step 1. First off take some parts cleaner of somesort and spray off your entire flywheel incase of excess metal. Not to say that you shouldn't trust your machinest but hey better safe then sorry.


Step 2. After cleaning the flywheel line the keyway up with the key on the end of the crank and slide the flywheel on as far as you can. Then take your nut and thread it on as far as you can. Make sure your Z is in gear and use a impact wrench to rattle it on until your wheels spin. Now you need to use a 27mm offset wrench or cresent wrench on the back nut and 17mm socket on the front and tighten her with all you've got.



Step 3. Once your flywheel is snug line the 6 allen bolt holes up with their mates. Hold your engine from rotating with a 17mm socket while you tighten the allens. Be sure to apply a little threadlocker to each of them prior to reinstallation. Make sure to double check all of the allens and also your 17mm bolt on the end of the crank to ensure you've gotten them all tight.



Step 4. Now place your cover back on with your gasket in place. Start by threading all of your 8mm bolts in back in their correct location. Aslo don't forget the one behind the starter gear and to reinstall the 2 in front of the sprocket through the cable bracket. Bring them all to finger tight then work your way in a cross pattern as you tighten them all. As for torque specs on these I didn't use one but you probably should i just reccomend that you get them all snug but don't over tighten them... after all its just a cover



Step 5. Your now ready to place the starter gear back in its location. Make sure your washers are in place and when you get your teeth to line up make sure that the seal around the outside of the cover doesn't roll out of its groove while you push the cover tight. Okay now tighten all three 8mm bolts.




Step 6. Now reinstall your case saver. Start your Z up letting it come to running temp then you want to shut it off and check your oil. If your oil is good your ready to take her out and rip.

Thanks to:
Jim @ LC Machine in Lowville NY for the machine work
1-315-376-8686
Paul @ Watertown Powersports in Watertown NY for their flywheel puller
1-315-782-4430

Very nice write up! Thanks for taking the time to put it together!

Here is the DRZ flywheel option too.
DRZ Flywheel Already 8 oz. lighter!

Dan

Awesome write up!!!

I honestly think it should be Pinned!

ill second that good job taking pics while doing it i usually get excited and forget to take pics just so i can get it back up and going to try it out...
good job

Add the torque specs and it should def. get pinned.
And also the price your machine shop charged.(just for reference)

Pinned!

That's simply the opinion of the local machinist you took it to, and numerous people told you the max that has been taken off a stocker is -9.8 ounces (performed by ProCycle, Jeff Homolka specifically).

I'm not bagging on you, but you state that as a max reduction like it's a fact and no more can possibly be taken off. Your local machinist didn't think he could take any more off. I don't want people on this board thinking that's the max reduction, just because you posted it the way you did. I know you said he couldn't take anymore off, clearly, but I don't want people getting the wrong idea. Bad rumors start from that kind of stuff...

Nice, though - and I'm not kidding!

one thing is too you can jack up the left side of the quad so you don't lose much oil if any at all. and another thing you might want to consider putting red loctite on those 6 allen bolts that hold the clutches to the flywheel....

if i remember, ill pm you or post the torque specs so you can put them in your first post

Thanks for the input guys glad you all liked it. I'll post the specs when i get a chance but Deer season just opened up in NY so i'll be busy

Well i added all of the torque specs and the people that helped me out.

Nice Write-Up dude! , Now I really need to Do mine!!!!

Theres a DRZ for sale on the forums for 40.00 man grab it!

interesting

very nice. thanks for the how to. i heard that the DRZe fly wheel was alot lighter than the Z's. i wonder how much can be taken off one of those the way you had it done. that would make for a really light fly wheel.

so is possible to just take out a z flywheel and put in the stock unshaved drze flywheel, or would it be a complete waste?

its not just the drze flywheel, you can get one off any drz400 or klx400. and yes for the price you can't beat it, it revs up faster

even if i leave it the way it is, because I wasn't planning on shaving it.

yes.... the drz wheel is something like 8 oz lighter

not to brag... but my trail tech -16 oz revs up even faster then a drze flywheel. very nice write up.

we already know this

Okay so I am seriously contemplating doing this mod but just want to make sure, If I put a stock drz or klx 400 flywheel, will it benefit my bike even though It is a basically stock motor with the exception of a full yohi and Uni fiter? How much more acceleration will you notice, alot or just some? Will I need to do the DRZE valve spring kit on my bike to help protect the top end?

yes....

no...

i just got my DRZE flywheel on and it definitely makes a difference. i have only rode it around my yard and up the road but i can tell its a bit snappier. i like it. i also made a tool to help make the job easier if you dont have a 27mm offset wrench like i didnt. i went to Sears and Lowes and called all my mechanic friends to see if any one had one but nothing. so what i did, i took a 27mm deep well socket and i had a big a$$ 1 1/4" wrench that i never use, and plus it was made in China so i didnt care much about modifying it. i cut off the end of the socket that goes on the ratchet. the hole in the socket isnt big enough for the 17mm socket to go through so i took my Dremel and bored it out to the size i needed to fit the 17mm socket through easily. i liked the idea of using the 1 1/4" wrench because the boxed in end is angled. so after getting the socket cut and bored out and ground down i took it over to my friend Lowels house and he welded it to the end of the wrench for me. i dont have a welder. i went home and used it and it worked great. the reason for making the tool was so i could hold the whole thing still so i could make sure i torqued the 17mm bolt to spec(89ft.lb.). i used an impact wrench to get it off. this thing would be good for the people that dont have and impact. here are some pics for yall.
here is the socket used.

before getting welded.


here is the socket cut and bored out.


here it is welded up.



in use.




here are some pics of the flywheels too. left is stock ltz. right is stock drze.

Thats a great idea, might have to try that when I have to remove mine here in a few days.

It works man, give it a whirl its really quite simple. Just post if you run into any problems and there will be countless people willing to help ya out.

i would say that this was one of the most simple mods you could do. it wasnt hard at all. i just didnt have the right tools so i had to improvise.

Nice work Trailrider ......I understand now about the dilemma you called about. My father in law took that 17mm bolt off while I was at work and I dont know how he did it. Good pics, If I decide to get a lighter flywheel I know where to borrow that tool from

Good info

sure. no problem. thanks man. if anyone needs or wants to borrow it just hit me up.

i forgot to post this also. my manual is a clymer manual for my Z400 and its a newer one. there is a typo in there. it says to use a 26mm on the big bolt but its actually a 27mm.