Building a DRM 400

[Marc.com]

I think the post code is correct, but you'd be better to ring him first
He charged me £90 all in and I supplied the cam to be reworked. I have a few spare.

I have never had a problem to get a cam from Megacycle. Though a lot of suppliers will shy away with sending stuff into Europe.

Main advantge with Megacycle is you are buying a new camshaft and not some reworked one on exchange. I have used a couple in TT500 engines and they work well.

If cams are built up then ground back often the cam profile is compromised.

[cloggy]

Not with Phil Joy they're not. The problem is the valve springs. The only USA one's I've had repeatedly sacked at around 6000 miles. Fine for racing but useless on the road
When you send a cam to Phil Joy he does the work, not some faceless employee of dubious provenance.

[Jens]

Might very well that way with TT500 cams but if you want Megacycle to hook you up with a DR400 cam you have to send them your old one, atleast according to their pricelist. So for me I guess it would be much easier to get one from Phil Joy, living in Sweden as I am.

Thought any about my suggestion Cloggman  ? You should check out the springs in Megacycles list as well, might be what you´re looking for...

JJ

and remember: Full throttle!

[cloggy]

I'm ok for springs
I use old Protec Keepers, chuck away the springs and put in ones from a 70's ford crossflow head. Thing is I've got two sets of keepers but I haven't got a spare set for anyone else. The cam Phil does is identical in profile to an XT one, it's got a bit more lift and more duration, but it's nothing extreme. The standard springs don't bind, they are just not quite strong enough to prevent valve bounce It makes more power in the midrange. With the standard cam there's a slight dip in the midrange. That's not noticeable till you change the cam. There's a mile long steep hill near here, over the Radnor Forest. With the standard cam I'd have to downshift  but with the Joy cam it would gain speed all the way up. I've changed lots of things but that was back to back with just a cam change

[oldfart]

Most of my power was gained by drilling holes in air box ( as per Clymer specs ) larger carb and jetting properly along with right sprocket combo .
Remember these old beasts develop most of thier power in low to mid rpm range .....so by short shifting and using the torque you will end up using all the gears rather than 2 maybe 3 .
I had a re-ground cam in mine for 6 months, and it would rev it's head off. But found it came at a cost ( mid range ) so have settle for a very mild cam that does not need revs .
Shttp://www.tighecams.com.au/prings are Std  but shimmed to be correct.

[cloggy]

Yeh I think the sort of high end power for road racing is not what's needed for scrambling. I'm very happy with my motor. I use a smaller SP370 carb and I opened up the airbox intake. On the DR400 there is an inside out filter so if you keep the airbox the most you can do is take the lid off completely. The Clymer manual I have mostly concerns itself with the previous model. From experience I found a lot of it's tuning tips rather generalised and not model specific. As standard all the varients are incredibly bunged up and most improvement comes from derestricting the intake and exhaust and rejetting to suit.
That said I've just got a pair of KLXs and the carb for that aneamic 250 is the same size and general model [VM32SS], so perhaps I should try the 33mm DR carb with the smaller carb's needle/needle jet combo.

[SON]

Interesting old thread, cams is interesting

[Graeme M]

Yeah... takes me back. I had an SP370 back in the day. Hi-comp piston, Peter Allen pipe, Megacycle cam, S&W valve springs, ported head, 36mm Mikuni and stock but opened up airbox. Cost me a bunch of dollars and was about as fast as a stock TT500. I sold it and bought a Yamaha...