DR400 mods

[ozyditcher]

Bulding a DRM400, does anyone know if someone makes a rev box or cut a wire?

[oldfart]

Not too sure what you mean by "cut a wire"    I find short shifting them into another gear works better than reving the shit out it.

[LWC82PE]

Do you mean a CDI unit ?

Anyway for all things DRM's Olfart is your guy to speak to, plus check out these threads

http://ozvmx.com/community/index.php?topic=4376.0

http://ozvmx.com/community/index.php?topic=943.0

This place in NZ makes CDI units for TT/XT yamahas so they might be able to do them for the DR. Keep in mind you can only do so much with an analog system.

http://cgi.ebay.com.au/YAMAHA-XT400-XT-400-XT550-XT-550-XT600-XT-600-IGNITION-/200516552054?pt=AU_Motorcycle_Parts_Accessories&hash=item2eafb7c576

http://www.erd.co.nz

[ozyditcher]

Thanks guys for all the info, yes i was talking about the CDI. Im a honda guy, i  got the bike 3weeks ago and raced it stock   with a full gate of 250 and 500 two strokes , one Mike Bell.  I see Tom White every weekend, il ask him and let you know.

[evo550]

Best thing you can do to those old 4 strokes is remove a counter balancer if they have one. Throttle response is drastically improved and they rev out much quicker. Only a slight increase in vibration at idle.
Don't know if suzuki fitted one to the DR's, but worth checking out.

[Curly3]

Thanks EVO, I've got a DR500 that I want to REV a bit harder and they have 2 counterbalance shafts,not to mention the benifit of the weight loss.
I'm not sure about the 400 engine.
Steve

[oldfart]

Dr/Sp  400 has no internal counter balance.....primary side drives clutch cam chain and oil pump - opposite side has flywheel .

[Curly3]

The balance shafts on the 500 both run parallel to the crank, one just in front of and one just behind, fitted to counteract the throw of the flywheel.
I'm definitely no expert and would love to hear from someone who has removed them.
Sorry for hijack.

[TT5 Matt]

if you want your 400 to rev out quicker fix a button rotor out of a chinese 140 and use the cdi charge coil to power up the 400 cdi box,also fix heavier valve springs and a better cam

[YUMASTEPSIDE]

I too would like to know about the balancer removal on the 500's 

                              Roger

[oldfart]

It's not hard  . Remove paddles along with drive chain on LHS of motor . Be warned motor will viabrates up thru handle bars making you hands go numb.
"DR 500"   race's up here in sunny QLd with  balances removed       I've tried it on my test mule and put them back 

[YUMASTEPSIDE]

........so that would be a big DON'T DO IT then   

                        Roger

[evo550]

I took counterbalancer out of a xt550 and only noticed slight increase in vibration at idle. My top triple clamp had rubber mounted handlebar clamps, that may have made a difference, not sure how suzi bars mount.

[Curly3]

It would be interesting to know if the vibration is only noticable at idle and reduces as peak revs build?

[DR500]

Too remove them completely you have to strip motor apart.If you just want to try them disconnected,just remove chain.I ,as old fart said have been racing my Dr500 for a few years with them removed.Not notice that much of a vibration difference.It wil rev harder and faster, but these old things really don't have to rev that hard,just change gear!