The O-Ring Mod for an FCR

[Ivanhoe]

what speed are you shifting into 5th?

approx. 50 mph give or take

[Wayward Son]

pretty low to be trying to pull 5th gear un less you are runnign 14/47 gearing or the like.

a jetting bog is not gear dependent.

these motors rev to 10,000 rpm.they like it.

[Motomike1]

pretty low to be trying to pull 5th gear un less you are runnign 14/47 gearing or the like.

a jetting bog is not gear dependent.

these motors rev to 10,000 rpm.they like it.[/QUOTE]

call me old school(I'm only 18), but that's hard to believe.

[mickeydee]

pretty low to be trying to pull 5th gear un less you are runnign 14/47 gearing or the like.

a jetting bog is not gear dependent.

these motors rev to 10,000 rpm.they like it.[/QUOTE]

call me old school(I'm only 18), but that's hard to believe.

my drz revs to 11,000 rpm.my old yz400 reved to 11300rpm.if its hard to believe look at the graph in my garage

[Wayward Son]

pretty low to be trying to pull 5th gear un less you are runnign 14/47 gearing or the like.

a jetting bog is not gear dependent.

these motors rev to 10,000 rpm.they like it.[/QUOTE]

call me old school(I'm only 18), but that's hard to believe.

whats hard to believe?this isnt opinion.

[William1]

A lot of guys seem to be terrified to rev their engine. They are under the mistaken belief that keeping the rev's down low will make the engine last longer. On a DRZ (and most modern thumpers) running under load below 5K is bad for the engine, puts too much stress on the parts. I only run it that low when steady state crusing on a flat road. If I am going to accelerate, I am at 6K at least.

[Ivanhoe]

pretty low to be trying to pull 5th gear un less you are runnign 14/47 gearing or the like.

I always wondered where the "correct" shift pts are. If I remember correctly it seems the owner's manual is way low (mph wise) I want to guess I was at 6000 + rpms at the 5th gear shift. I'll pay more attention to the tach (Vapor) (and no, not 14/47 but 15/41 gearing)

thanks Eddie.

[William1]

15/41 shift point is a minumum of 60, I think.

Take a read of these:

https://www.thumpertalk.com/forum/showthread.php?t=562230

https://www.thumpertalk.com/forum/sho...d.php?t=441304

[headster]

and a max of around 75mph

[Ivanhoe]

thanks for the links William.

So, after plugging in my individual gearing, tire size etc. do I use 6000 rpm's as my guide or higher?

Also, my apologies for getting this thread off track from the "O" ring write up.

Rod

[William1]

I do not try to accelerate hard in 3rd on up hard if after the shift, my rpm's are below 6K. There is sufficient tourqe in the lower gears to be at a lower rpm. But even then, the minimum engine speed should be at least 4K.

When you ride, you''ll notice there is a point when the acceleration is seamless and effortless for the engine. Typically, this point goes up in rpms as you go up in gears.

[Motomike1]

whats hard to believe?this isnt opinion.

I believe they rev that high, I just didn't know that they like to be revved that high. I could see hitting the rev limiter every now and then while riding, I do that all the time. But I figured it to be bad for the engine to keep it up that high. am i wrong?

[Wayward Son]

holding it int he rev limiter isnt a good idea.

revving the bike to the limiter and then shifting isnt hurting any thing.

my point was lugging the motor around isnt good for it.

most people dont realize what rpm they are revving the motor to any way.i bet its higher than you think.

[stringburner]

After spending time w/ a bike, you should get to a point where you realize the "happy" range of your engine. It took me a few days on my DRZ to figure it out, especially w/ it being my first thumper, and coming from a background of inline 4's & 2-strokes. Now we're like old pals.

[ollie134058]

Gyday Guys, Nice Post I just bought a JD kit for my 04 wrf450 and this mod was included, also it had a thin o-ring for offroad and trail use and the thicker one for MX and supercross. I have 3 fingers amputated at the outer knuckles on the right hand (long story) so I can understand some of your frustrations, I use my old standard husky 360 spring puller to get it done. Maybe we should have a Post of our favorite tools that we couldn't do without!!

cheers Ollie

04 WRF450

Sydney Australia

[6nine4]

For the O-ring mod do you need to use the exact size 7/16" O.D. X 1/4" I.D. X 3/32" thick? I have been to two hardware stores and the closest I found was 1/4" I.D. x 1/8" thick and cant remember the O.D. Can I just double up the size I found?

[William1]

You can certainly try the one you found. I would not double it up as it sounds like the one you got is thicker than the rec. one.

[6nine4]

Well I went to 6 places and finally found the right size O-rings. No hardware or automotive store here carried that size. I had to go to a hydrolic hose shop and they came in a 20 pack so I have plenty of spares now. Thanks for the help.

[Wayward Son]

i just bought several packs at home depot.........

[6nine4]

Our Home Depot here only had some variaty plumbing packs with with a bunch of different sizes in them and it didnt list what sizes were in there and they looked to thin and had no sizes listed on them. I asked if they had any other packs of O-rings and they said what you see is what we got. He was a bad salesman.