RD250 Cafe – Intro

I went to pick up my newest garage endeavor last Friday morning, a 1975 Yamaha RD250, destined to become a cafe racer. I was anxious as I made circles around the bike at the sellers house, trying to look and sound somewhat confident that I knew what I was talking about.  A healthy dose of research got me up to speed pretty quickly the night before. The bike was in decent shape, but had enough wrong with it that it would need some TLC before it could be trusted as a “daily runner”. The seller had a garage full of interesting and rare mopeds that were higher on his project priority list than the RD, so he was looking to get back what he paid for it originally and be done with it.

Known Issues –

1. Cylinder fouling – Prior to my picking up the bike, the seller indicated that the right cylinder had issues with fouling its plug really bad, to the point that it would cut out and turn a 250cc bike into a 125. When I got to his house, he said he had taken it around the block that morning and noticed that the right cylinder was fine, but the left was acting like it wanted to foul out. So, one things for sure, there’s some tweaking to be done to the air/fuel mixture in general on this bike. At least things were leaning to the “too rich” side and not “too lean”. Seller said one of the pipe baffles was unpacked, and he was running one side without its pod filter. He put new idle and main jets on the carbs as part of his debug effort, but that’s as far as he got.
   

   Right plug after a mile ride, didn’t look much different before I started…

2. Transmission oil leak – There’s a very small oil leak from the transmission. No other information other than that, probably just needs a new gasket
3. Tank – Holy cow someone went to town on the poor gas tank. I didn’t see evidence of it being layed down (pipes look good, and the side of the tank isn’t scratched or dented). It looks more like someone took a baseball bat to the top of the tank. Or several paint cans fell from a shelf onto the top of it. It works well enough, but it looks awful, and the petcock tends to leak gas if you don’t shut the fuel off. I’m not sure if this is something I can repair/refinish, but I’d probably be better off just getting a whole new tank.
   

   The tank is in pretty poor shape

4. Disabled oil injection – These bikes come with the Yamaha Autolube system that pumps oil into the engine. One of the previous owners disabled the injection and just went with a premix of oil and gas in the tank (32:1 was what the seller was using, with synthetic marine 2-stroke oil). The oil pump could have just been disabled out of preference, or maybe it stopped working. To be determined…

Where to Start?

When I got the bike into my garage after riding it home (and having it die on me in the middle of two high traffic areas where I had to push it across the road), I just sat and stared at it, unsure of where I would even begin on a project like this. I have zero auto/mechanic experience, but I’ve always wanted to learn. I spent the evening looking around for inspiration, and found two great “how to begin a cafe conversion” articles. The first, a reddit thread on r/motorcycles, laid out that a tenet of cafe conversion is reduction, reduction, reduction. “If the bike runs without it, toss it”. That let me look at my bike in a new perspective, from what I could cut out and still have it run (and be street legal).

The second was an in-progress article from the Utah Cafe Racer group. It laid out the most iconic features found on most cafe-styled bikes, and although I could have probably picked these out myself, it was nice to have verification of what would need changed from an aesthetics perspective.

But really, before I start cutting things away, I want the bike in daily runner condition. That way, I know exactly what parts NEED replacing, and what parts I can get away with reusing. And if things don’t work 6 months down the road after I’ve had the bike in pieces, I’ll know it’s something I did.

STEP 1 for me is going to be the cylinder issues. I’m going to take apart the carburetors, clean them thoroughly and make sure the baffles in both pipes are packed well. Once I can get both cylinders running without fouling out (and with the pod filters installed), I can move on to the transmission oil leak.

Keeping Motivated

First off – this thing is a blast to ride, even in its stock form. The 6k power band surprised me the first time, but then it was ear-to-ear grins. It’ll be hard to not get to rid the thing while it’s taken apart, but I’m excited by the prospect of what it will be when it’s all said and done.

Once I start taking it apart, I’ll have to get my moto fix on my Vstrom, who I think is already jealous of the attention-stealing addition to the family.

Additionally, I’ve found several inspiring pics of builds I’d like to pull features from on my own conversion. I’ll be updating the site a lot once things get started.