I did some measurements on the different bores I have. "Sleeve" means the overall height of the sleeve. The pins with two thicknesses are tapered on the inside; they get thinner towards the edge. Notice the pin dia is different between the 250 and the 350, so you can't put the 350's piston on the 250's rod (I was told you could).
this is the counterweight drive gear on the crank. Jesse Kein says there is a problem with the pin slipping out and causing catastrophic damage. I can't remember what Jesse's solution was. I decided to weld mine. I did a fusion weld (no filler rod) so I wouldn't upset the balance.
Flywheel weights: 91 DR250S: 4lb, 3oz 98 DR350: 3lb, 15oz The manual suggests jamming a penny between gears to stop them from spinning when you're trying to torque things down. I tried this to torque the flywheel bolt down (95 ft/lb) and I broke a tooth off the oil pump drive gear ($30 replacement). So don't try that. When swapping the trannies I swapped all the internal parts (gears, shafts, forks, and drum). The reassembled trannies both bound up. I spent a long time trying to figure out what was wrong. I finally swapped the drums back and they worked. I examined the drums closely and couldn't find anything different about the two, but it appears the drum needs to stay with the case it was meant for.
In order to get the primary drive ratio I want, I need the 91 DR250S's clutch basket. So I put in the whole clutch from the 250. Does anyone know if there's a difference between this clutch and the '98 350 kicker's?
Great work and awesome thread! Do you need to modify the engine block to get the cylinder with the 440 sleeve to fit?
The hole in the case is able 2.5mm bigger than the 440cc sleeve. My guess it the 460cc kit takes up the entire hole. Due to some of the bolt locations, you wouldn't be able to bore out the cases much larger, maybe a couple mm's, but it would be pretty pointless.
People say all sorts of things. With enough time and money I'm sure you could. The stock cases can accept a sleeve OD of up to 93mm. With the 71.2mm stroke of the 350's crank, you would need a 93.9mm bore to make 500CCs. I don't know how thick a sleeve needs to be, but you're looking at widening the cases (and moving some case bolts) or getting a stroked crank. I've never heard of a stroked crank for this bike, but that doesn't mean someone hasn't made one
On your neutral switch "missing a cover". I think that's just how they are. Mine was the same way. I think I read about someone grinding an offset crank pin to make a stroker crank for one of these. Jesse would probably know. You do some nice welding, BTW.
I bored mine out to 450 and the engineers that did the sleeve and boring said it would be entirely possible to go to 500 with the room that was left. The kit I used came from LA Sleeve and just maybe their sleeves are a bit thinner. I just went out and measured a set of cases I have and the case hole was 98.26 mm so with that you could fit a sleeve that was damn close to 98 don't yer think???? With your figures that would leave a 4mm sleeve thickness. Stock thickness just measured at 3.5 mm.
Sweet build. I would love to have the wider spread tranny, cant wait to hear how the final result works. FWIW my DR350 has an RMX swinger on it that is quiet stiff. I got it that way so I don't know if it was an easy swap but it looks to be a bolt up fix. Might be easier than welding the stock-er.
I would love to hear from anyone who has done this, some people say its a pain and others say easy... Awsome build pablo, I wish I was knowedgable enough to tear that far into one. The higher 6th gear would be perfect!
I'd love to hear more about this too. Do you have any pictures of the shock mounts? Do you know what year/model your swingarm is from?
Someone on one of the DR350 threads was recently commenting on their Jesse-modified exhaust. Shearboy, was that you? Anyway, I'd like to keep this bike real quiet and wanted to know if there was a noticeable difference in sound after Jesse's mod. Anyone?
Yes. It sounds better, deeper with a bit more volume but is still well muffled. But, if you really want it quiet, don't deviate from stock.
The DR250S's footpeg brackets are rubber-mounted and heavier than the hard-mounted DR350's brackets. I know some of these posts seem real random, but I'm just trying to document the differences in the two bikes as I come across them.
