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Hi guys,

I'm just curious about this... is there porting that would increase power for stock exhaust and intake and not diminish from bottom and mid rage power? I honestly doubt I will ever touch the ports on these stock RD400 jugs I had to find and buy but I am curious. I'm more interested in reliability and longevity so widening the exhaust or intake ports is a no no for me.

Thank you

Hi again,

I'm just wondering if anyone would know what would the powerband be like if you have cylinders like the one's I found with stock pipes and intake? Stock is 35mm and these butchered jugs were at 28mm.

Wanted to ask you guys if having the intakes joined like an RZ is worth the expense on my RD400c ?

All I can find out is that it smooths things out... but unless it's a guaranteed thing I dont really wan to waste money on it.

TY

Hi everyone,

Figured I'd start a thread here to document the restoration of an RD400c I found in Toronto.

I've had two-strokes in the past...a couple RZ350's and an RD400g. I got out of messing with these old smokers around 6 years ago because I got fed up with the money pits they can easily turn into and the constant issues they seem to have. Endless jetting and ill running being the biggest headaches, of course.

Yet, here I am again! I saw one for sale and I wanted it so bad. I love the character of these bikes an riding them gives me a joy I dont get on newer bikes.

I told myself if I could get the asking price to a point where I was comfortable I'd get the bike and put it back to stock and pray that in stock form the damn thing would run properly and be reliable. I told the seller I knew I'd have sink a couple grand into it just to get it mechanically sound and he agreed and dropped the price for me after it wasnt selling for more than a month. I always wanted a completely stock bike with the original intake and exhaust system because I love how much torque these bikes have when they arent piped and 2-into-1'd and ported to death. In my mind a bike like that is nothing more than a pain in the ass to drive around town from light to light or go on nice relaxing rides with. The loud silencers and intake drone got old real fast for me. Once I put the stock airbox and exhausts on the RD400g I had I was stunned with how wonderful and torquey these bikes become. Plus I love the sound of stock pipes.

Here is the bike I bought and the last pic is what I intend it to look like. It's an R1/R6 blue not one of the original blues but I love it. Everything is there so I am happy. All the chrome is in good shape, too. Only things I see are the front rim is gold and not orig (unless someone painted it) and the seat cover is aftermarket with the yellow piping to match the paint someone did in the past. According to the ownership this  bike was black when it arrived in Canada in 1976. The important thing was the bike was all stock and had everything it was built with and this one was very close.

I'd like to do what I can to get more low end grunt on this RD400c. I had a 1980 RD400G for a few years and it was so torquey in the low/mid I loved it so much for driving around town.

The only thing I can think of is correct the squish. If I'm correct that will add power mostly to low mid ? I have all stock intake track and stock exhausts.

Any other tricks?

Hi guys,

Am rebuilding a 1976 RD400c and I'm wondering if these were the stock con rods that are in it that say 2R9 on them. It's a canadian bike.

Ive ordered some prox con rods from economy-cycle to replace them since I figured I'd just have the entire crank rebuild but I am curious about the 2R9 pars.

Thanks!