DRM 400

[oldfart]

Clutch springs in mine don't show any sign of sag , bike is thrashed at regular Mx meetings. Springs are std Dr 400 and checked at Xmas when motor was given freshen up . Check plate thickness ( 2.65 - 2.95     liimt =2.35 )    ......clutch spring length new = 40.5     limit = 38.5
the above is for DR 400     
Sp 370 has a different spring tolerance           new = 40.5     limit = 39.1
Generally the clutch on these old thumpers are more than adequite to cope with exta HP gains

[cloggy]

I've got a box of clutch plates, all well within tolerance and all pulled due to slippage. Put new ones in and slippage stops. I've never got to the bottom of it. I don't use aftermarket oil additives, just mineral oil.
The springs do sack eventually though.
Recently I've set the motor up with a smaller carb. There seems more low down grunt and it starts to slip after a very few thousand: before the plates would last well over a year.
I was out in the wet recently {Wales} and noticed that it went sideways at a touch of the throttle, this is on road with road wheels. I'm still waiting for the {hopefully} right fork springs to arrive.
Have you got fork springs you're happy with yet?

[oldfart]

Fronk forks  you trying to wind me up  still not happy with . Last meeting, I had what I thought all sorted out untill after secound race I had noticed they where bottoming out over small jumps and at the end of the meet the seals had shit themselves ( all balls triple seal ...red )
Back to the drawing board

Maybe change your brand of oil and see if slipage stops .....    most of my power is at mid to top end ( cam profile )

[cloggy]

I've tried that. At present there's only a touch of slip when the engine is warming up. Once hot it doesn't slip.
I've ordered a set of  fork springs. When I get and try them I'll let you know.

[LWC82PE]

have you tryed the Leak Proof seals or plain old OEM?

[ola_martin]

MotocrossAction article please? Anyone?

[Jens]

Hi folks!

Much good useful reading in this thread. Haven´t had the pennies to invest in a users manual yet, believe me I will, so my question is if there´s anyone of you sitting on a DR400 manual and is willing to scan the elecrical wiring diagram for me? I would be eternally thankful. Heading for winter in Australia, soon summer here and I haven't gotten any of my bikes in running condition, guess that´s the downside of being a parent, if I´d only known  Managed to score a ´85 RM500 front forks and now looking for a ´84 front hub to go with it. After that I should have all the parts for a complete bike except plastics and decals which are easy to come by. Guess I know what to do this autumn/winter, besides being a dad...

So long for now!

[oldfart]

Jens, Yes I have a CLYMER  service book which has a wiring diagram on the last page.
Will get me daughter to show me how to scan and load onto site   
Me thinks that the RM 500 forks might be too tall, and you would need a step ladder to mount your bike ?

[oldfart]

There are 2 types Dr 400 and Sp 400

[oldfart]

Sp  400

[bazza]

hey old fart line me up for a beer at CD,shame i did not keep maico spring specs for DRM they were great and the envy of many TT riders who rode the drm

[cloggy]

Bazza, that sounds like past tense. Have you sold the DRM?
I'm still waiting for my maico springs to arrive......
Jens. hubs are available new from Crooks suzuki in the UK. Martin may well do you a deal. The hub is identical to the RM125. It's the brake backing plate which is different. Martin should have these as well. What are no longer listed or available new are the cams and lever assembly that fit in the back plate. I have to say the end result is not particularly impressive, even with after market specialist shoes and skimming.... I don't think this is much better than the original SLS DR brake

[Jens]

Thanks a LOT Oldfart! And give my regards to your daughter as well  Yeah, the bike might be awfully high but I´ll bring a ladder when ever time to mount. Also been thinking about moving the footrests backwards, did that on my Curtis and it turned out a much better ride, easier over jumps, easier to balance. Any of you ever done that? and what´s your input on that? When it comes to forks I´ve found two other interesting deals for 82/83 RM500 forks so I´ll see what I´ll end up with. Propably a million other things I wanna ask but I´ll get back to you all. Cloggy, thanks for the info on the hubs, if I won´t be able to score a hub togehter with the forks I´ll definately get int touch with Crooks, the DR400 hub is big, awfully big and propably weighs there after. Ooooh, one other thing, the kickstarter on the DR400 is that the same as on the RM models? same splines?

So long for now folks!

[oldfart]

Dr 500 use the same kicker, Rm 79 -80  are about 100mm shorter and fowl with the frame- plus I recon you need the length to kick em over  ....Yes I moved my peg mounts back ( 25mm ) so as the rear bolt is inline with the down tube, bike handles better . Down side kicker has a shorter stroke and your boots wear the shit of of your side covers .

[Jens]

My thought on the pegs... I skipped the -85 forks for a pair from -82 including wheel. I guess that´s for the best since the bike is from -82 aswell. You say I wear out the plastics with my boots! Well, off they go Thinking about the kicker, engine turns over really easy thanks to the decompresser and I can score a NOS RM kicker quite cheap AND my "old" kicker isn´t an original and looks like shite, pardon my french... Really looking forward to this project. My Curtis, which is undergoing renovation, kinda died out on me a couple of years back AND I´ve been living in a flat without garage AND becoming a parent adn so on and on... Moving to a house this fall with a brand new double garage! Which means I can finally relief my mother from a couple of other projects and my old Lotus Elan +2. Life is sweet  Once again Oldfart, thanks for the scans. O yeah, talked with a specials bikeshop the other week about my shocks. They said they could shorten them for me which means I don´t have to look for new once (got a pair of Ohlins piggybacks from a Husky in decent condition) and thus saving a couple of pennies. Sometimes things go really easy 

So long folks!