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1983 Honda NS 250 F - at Mosport in 2007

1983 Honda NS 250 F

Originally built as a street bike, the Honda NS 250 makes a very reliable package converted for vintage racing. Honda's 250 cc 2-stroke, liquid cooled, v-twin is very reliable and less maintenance intensive than the pure-bred two-stroke racers. I purchased this bike in 2005, already stripped of it's street gear and safety-wired, and have been racing it since then. Except for welding exhaust parts back on when they fall off, I've done very little to it. Honda never sold this model into the North American market, so it's very hard to buy parts for it; I'm now relying more on fabrication expertise, than parts-sourcing expertise if anything breaks.

The photos below were taken in February of 2008, while the NS is 'undressed' for the winter, with the gas-tank and body-work off, and the exhaust system removed. One of the only problems I've had with the bike has been the exhaust system, which comes undone at one end and sheds silencers at the other end. The undoing part I can cope with - I've been siliconing in my exhaust mounting bolts for several years, and hopefully I'll get that properly fixed this winter; heli-coils into the cylinder where the exhaust mounting bolt goes. The problem at the other end has been much more involved. The aftermarket silencers are very light, but the metal of the stock pipes is aging, apparently, and they break off; usually right next to the previous weld. In fact, these pipes are pretty much the reason I went to welding school, so on some level I suppose I'm grateful. Still, I'd like to run a race weekend without exhaust parts detaching themselves, and I think that will entail finding a new way to mount my exhaust system.

NS250F original Japanese warning label on gastank

This particular bike was originally sold into the Japanese market, and still bears the original warning label on the gas tank. I've removed the English warning labels from my modern streetbikes, but this incomprehensible sticker delights me, and I've been carefully preserving it. The tank came to me in dented condition, but this charming sticker has given me an excuse to leave the tank unrepaired, with only minor paint touch-ups.

NS250F fuel tank seen from above
The NS 250 F Gas tank as seen from above, the right hand side dent showing slightly.

NS250 Gas Tank from left side

Gas tank of the Honda NS 250 F as seen from the left hand side. This is actually the 'good' side of this tank, the slight scratches to my sponsors sticker we delivered by a bully of a TZ50 that managed to come loose from it's tie-downs while strapped in next to my bike. Fortunately the light-weight 50 didn't do much damage to the paint or the tank, the sticker bore the worst of it. The other side is dented, from an right-side crash before the bike came into my posession.

Honda NS 250 front wheel as seen from right side
The front wheel of the NS, the beautiful rims obscured by the large front disc. Stopping power on this bike is impressive, with two generous discs, and good feel though braided steel brake lines (the one showing in the photo was an emergency repair mid-way through a race weekend, and it needs to be replaced soon with a line of the proper length). Agressive braking does not upset the composure of the chassis.

NS 250 Honda - front left side view
39 mm forks, now updated with progressive suspension springs, work quite well, although I seem to have a slight leak still, despite replacing all the seals last winter. The square tube frame is amazingly solid, bracing around the steering head, and across the frame above the motor, all contribute to a bike virtually free of flex or wriggle of any kind.

Honda NS 250 F - frame and swingarm seen from the right side
Rear swingarm is made of rectangular section tubing, and has additional square-tube bracing underneath, quite modern for it's era, and more substantially braced than many heavier and more modern bikes. The NS chassis is solid from front to back, and well suspended too. I believe the rear suspension is entirely original, and the front suspension has only recently been updated.

NS250F motor seen through the frame from above
This view through the frame from above gives a good look at the front end of the frame, how solidly it's braced at the front end of the bike. You can see the top of the rear cylinder and the top of the rear shock too. The angled spark-plug cap was difficult to replace until we worked out that it was the same as Honda's RS125, for which parts are still available in Canada.

NS250F rear suspension through the frame
The rear suspension, as seen through the frame from behind the bike. The solid bracing across the swing-arm is visible too. Chain appears in good (clean) condition, but it's wearing, and will be replaced this winter.
NS250F rear wheel and swing-arm
This picture gives a better view of the NS's beautiful rims, the rear brake disc is small but sufficient, and the bike stops very efficiently. The spools have been added to the rear to accommodate a race stand, and one of Tim's beautiful hand fabricated brackets holds up the rear brake fluid reservoir, and bodywork too.

NS250 Honda right side peg bracket
The right side peg bracket shown here is similar to the left hand side bracket - a sculpted looking piece of cast aluminum - will likely be replaced this year. I'm hoping Tim can design and fabricate a set of rear-set foot-pegs and controls for the NS this winter. These pegs are relatively low, scraping badly at the Shannonville/Nelson circuit, and they aren't equipped with springs, so when they get folded up, they stay up while you fish around with your toe hoping to find they are still attached to the bike. Hence my enthusiasm for replacing them with higher pegs.

NS250 Carburetors as seen from above
The two carburetors nestle between the two cylinders of the 'V'. Carbs are entirely original to the best of my knowledge. The only aspect of the fuel system that has been updated are some o-rings in the fuel petcock, and new fuel lines.

NS250F in Streetbike form
An original NS 250 F as it came from Honda, in a different colour scheme than the bike I own. I believe this is a brochure photograph from the 1980's, from the Honda marketing department, but it's of uncertain internet provenance, so I can't be sure of the original source.

NS 250 F 1983 Honda - at Mosport in 2007

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