ESE's works engine tuner

[TZ350]

On a standard NSR MC21 head the plug is quite shrouded. I was surprised at how ugly shrouded the standard NSR250 MC21 heads are.



Following Wobblys suggestion I spot faced the plug seat back 2.5mm. Maybe a good idea for any standard NSR250 head too.

The idea of a one off lots of work bespoke center plug rainbow head is pretty useless when you are building several engines and looking for repeatable practicality.

When I have figured out how to produce easily repeatable no compromise center plug heads I will be able to make a back to back dyno comparison with my original modified NSR head, and maybe with a completely standard one too, it will be interesting to see how that goes.

[F5 Dave]

Geez check out the drag dude with no gloves and legs like Kate Moss.

[TZ350]

If anyone can sell me a HONDA NOVA DASH 125 RS motor (or several) bottom ends. I would be interested. I don't need the cylinder or head so older motors that have seen better days would be Ok for what I need.

[husaberg]

Geez check out the drag dude with no gloves and legs like Kate Moss.

Sounds like you were........

[andra_rgv120]

The Dash125 and LS125 are similar, but not identical. The crank for one is different. The drag boys use a modified LS crank in the Dash cases.

I heard a story that the LS engine started life as a Dash, with HRC intervention. Small mods here and there, such as the crank for example. Not sure on the other differences.

I used to have a Dash some 15+ years ago, but it got nicked one night from outside my grotty apartment block. I have two LS's in the shed, but never done more than park them and throw a blanket over. One day I'll dig them out........

Thank you for the information matt

[andra_rgv120]

By the way, i found this interesting video, honda nova dash beat honda rs ( rs 125 motor in dash chassis) in drag race



Race start @7:27

How Is it possible street/production based engine beat gp125 engine?

[jonny quest]

Honda vowed to never make another 2 stroke! Surprised they are still producing them

[SwePatrick]

How Is it possible street/production based engine beat gp125 engine?

Everything can happen in dragracing, This race i would say it was a bad start of the looser.

[F5 Dave]

Geez first time I launched my RS125 in anger it was insane how long you have to let the clutch out so tall is first gear. After about what seemed like 10seconds of launch I let go of the last 1/2mm of clutch travel and it bogged.

Nothing a 60 tooth rear sprocket wouldn't fix.

Beat RS125 round kart track on my 50. He just couldn't get going.

[jasonu]

After about what seemed like 10seconds of launch I let go of the last 1/2mm of clutch travel and it bogged.
.

Sounds like all your bikes....

[Matt@TYGA]

The guys here spend an absolute fortune on their drag bikes.

I've helped out on a couple of occasions with one of the guys who was kicking ass.

Starting with a Dash125 motor, they'd mill out the cases and around the reed valve area, weld bits in here and there and fit an NSR150 (or similar) reed valve.

The crank pin hole would be welded up and rebored at a new stroke. Also rings welded onto the crank wheels to increase the inertia.

The cylinder would have a new liner popped in and ported. Strangely though, back then they always insisted on a single exhaust port. Also, their measuring of the ports was a little suspect as they'd use a ruler to check.

Spent one day at a test with this guy. I was helping to set up an Ignitech on his 160cc racer. By the end of the day he'd set a new 1/4 mile record and highest top speed......and I'd sold 20 ignition units :-)

It was a little strange as I was the only foreigner there, and plugging the bike into a laptop.......well, I may as well have been dressed as a clown doing cartwheels down the strip.......every time the bike came back and I plugged it in, a crowd gathered to see what was going on. Quite daunting but amusing all the same.

[jonny quest]

How much HP are those bikes making Matt?

[Matt@TYGA]

How much HP are those bikes making Matt?

No one that I know of has put one on the dyno, so don't know.

Offered free dyno time to my friend, but he never showed up.

The one thing that helps is that they cut and drill everything and get the bikes down to about 60kg, and the riders are around 45kg (including helmet, fingerless gloves and flipflops).

Sorry, can't answer that one, but I too would really like to know.

[andra_rgv120]

.....

Also rings welded onto the crank wheels to increase the inertia.

....

welded like this???

[sispeed]

Hello, a little offtopic a Vid to my 2 race in Hockenheim.
Bike with some useful insights from this forum Aircooled RD 250.
Thank you for all the useful informations her

Regards Siggi