Another trick DR400

[Marc.com]

Anyone maybe Cloggy know the pedigree of this bit of DR trickeree

Just found a couple of decent barrels in the back of my shed so almost have enough bits for a rebuild pity 420cc piston is not about anymore

[SON]

Curtis, but since it is a forum members bike he should be allowed to post its story,
Lovely bike just needs a RN/RH or TM Tank.

[ola_martin]

77 RM125 tank has been tested and will go on.

Currently working on replacing the YZ490 fork for something pre 80 era, the modern WP's (that fitted right on my Maico 490  ) for a set of old Ohlins I think.

I have ordered new 70's look plastics, and will make some new sidecovers etc.

I settled on the look it currently have, with sidecovers instad of the "numberplaterearfender" many Curtis' use....

And a kickstarter that actually fits the bike! According to my knee the one on it is a piece if sh.t!

[ola_martin]

But, I'm having trouble making it run properly, just fires a couple of strokes and choughs out, sometimes it idles 20-30 seconds before it choughs out. Stops if I touch the throttle.
I think it's an ignition problem, the points sparks heavily while running, and the spark on the plug is weak, so I ordered a new condenser...

But, can someone tell me if the electronic ignition from a DR/SP400 will fit the SP370 engine that's in it??

[Marc.com]

Hey Ola, you are starting to get quite a herd of 4 stroke specials  Seems like Curtis fitted every motor going to the HL 500 frame.

[ola_martin]

You know Brian Curtis made all the NVT HL frames?

He made his own version with Honda XL500, I've read about 25pcs. He made 3 with Yamaha XT, wich actually was quite different from the HL frame although about the same design.
And this one-off, wich is based on the Hondaframe, but the whole frame is shorter to fit nice and tight around the Suki engine.

Got a CheneyXT, CheneyXL, the HLreplica and this one now, so the "British specialframe wit trailbikeengine" collection is coming along nicely

[Marc.com]

You know Brian Curtis made all the NVT HL frames?

Maybe they should be called Curtis replicas  , so is the JBR Honda based on the Curtis Honda ?

[ola_martin]

Nope, they're CCM's with Hondaengines.

[firko]

Nope, they're CCM's with Hondaengines.

I always thought that Eric Cheney built the JBR frames so I've learned something. That's a nice Suzuki Martin. Really nice

[ola_martin]

Guess it's a compliment to be able to tell Firko something VMX he didn't already know...

In fear of making this a Hondathread in the Suki section....

Curtis Honda:


JBR:


CCM:


And finally, Simon's (Cheney) version:

[oldfart]

I just don't get it ..... why they didn't go the extra distance to make an airbox The pods may have work well, but the bike looks unfinished in my eyes.
 

[ola_martin]

But, I'm having trouble making it run properly, just fires a couple of strokes and choughs out, sometimes it idles 20-30 seconds before it choughs out. Stops if I touch the throttle.
I think it's an ignition problem, the points sparks heavily while running, and the spark on the plug is weak, so I ordered a new condenser...

But, can someone tell me if the electronic ignition from a DR/SP400 will fit the SP370 engine that's in it??

Please don't forget this...

[oldfart]

 Will check it out tommorow .....I'm sure I have one that has been covered   

[cloggy]

 No It won't.The flywheel is totally different on the 400 and all the electronics are attached to the outer cover, save the CDI. There's not a lot the same on the 400, it's a beefed up engine. I don't know if the timing side shaft is identical. If it were you might be able to fit the flywheel and side cover, but I doubt it. The 370 was supposed to be the peppier motor, just not as tough.
 You sure it isn't running super rich or lean straight off idle? I'd change the points too.

[ola_martin]

Thanks, I've ordered the points too.

It feels rich, won't go with choke or startgas-spray at all, but I just feel the spark is weak. have tried to file and adjust the points, and changed to some condenser I had lying around (new, but I don't know condition), and it helped for about 30 seconds...
 
Mabe I should go through the carb, mikuni 36, to see if somethings wrong/clogged, but I'm told it was running and starting ok so I think the jetting should be ok.