Honda Spree and Elite 50 Forums

Weight drag is not going to help that. Got guys that weight over 230lbs that run 8to1 gears going 70+mph.You need to take off Drag in the gears. Again you were at 10.3k rpm but only going 71mph . Yeah the trans is setup to hold that rev but that doesn't mean its going to put the power to the wheels. There is a point were you reach the over gearing point of the setup. In this case these 72cc setup doesn't put out enough torque and hp to turn gears efficiently like 7.58 or smaller. Just not enough power and torque. That 71 mph speed you hit can be done with 8.44to1 gears and would get there way faster than 7.58 gears would.

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Makes sense to me. I may keep the 7.6s. Less work.

Mathematically you should be turning x rpms and getting x mph according to the gear chart. But Like baka said if your motor doesnt have the balls to push the gears then your not going to reach that x mph with the x rpms. Theres big heavy guys whacking high speeds on 72cc with good tuning. I dont see the point in ultra high top speed on a moped. If your trying to go that fast then just get a motorcycle. I catch my thrills with high torque and 55 mph wheelies.

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Before beginning assembly of Flash 6, let's have a look at the M'Arn (Malossi Iron) cylinder kit.Isn't she a Beauty. That's the V8 28mm 72cc pipe. All told, good for about 60MPH with good tuning.The bore looks just like new, except for the Motul coating from the 4 hours of run time.Except for some thin coated-on deposits in the center, the piston looks new too. That 50-50% Pump Premium-AvGas protected it from self-immolation with the 175psi compression ratio measured on assembly. It was actually a hair higher before disassembly, suggesting nicely seated rings.The spark plug picture looks nothing like the plug in good light. It was a good bit darker than it appears here. Sort-of Caramel color, but it sure looks lean in this photo.
Dismantlage was painless. My greased base gasket came off with a "Pop", in one piece, stuck the the cyliinder base without tears or missing chunks. I do this every time I assemble now.

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Time to pull out Parts and see what I've got. I really couldn't see any difference between the MHR and the M'Arn heads. In fact they look like they were cast in the same mold, including the "89" sunburst marking on the lower edges. Contrasting the shallow, progressive hemispheric center section of the MHR, Polini's Corsa head has a much sharper "cliff" leading into the central recess and plug hole. I'm confident that a great deal of thought from the Inginieres of the rival companies led to the very different designs. I have given some thought to putting the Polini head atop the MHR cylinder just to measure compression. Maybe even try to start it? Nah, the oil would probably turn to blood...

That's the cleaned-up M'Arn piston in the foreground, BTW. It looked perfect except for staining between the crown and the upper ring. Malossi sure makes durable stuff - remember 175 compression - Yikes! Speakin' of pistons,there's not much to tell the M'Arn (Left) and MHR apart is there. Slightly narrower, more squared-off boost port window with nearly identical area. The cylinder ports are quite different, and of course without doing a tracing there's little doubt that the ports are located to produce power at a much higher RPM on the MHR. The MHR exhaust port is remarkably bigger than the Iron's.So here she is all buttoned up with the Simioni exhaust, ready to go bolt on this afternoon.

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Baka-san gave me good advice on heat-cycling a few times before attempting to rev the engine, which I intend to follow. I have about a gallon of 50/50 AvGas in the tank that I'll burn mostly idling. Tuning and performance testing will have to wait until the week of the 18th. Tha's all for now.

Yes Baka is a great resource for these scooters!

The MHR and the cast iron use the same head.

what spark plug did you run ?????
that one look like a hot plug???
swimmingfree

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That'd be an Iridium BR8HIX.
Heat cycles were uneventful. Even took a short ride, diggin the quiet Simioni. One problem, though...Yes, it's that close. Taps with a small bump. Will break lens if I hit a big one. I don't particularly care for the JDM TAIL, but it's that or a different pipe. Too bad because the MHR had pretty good low end with the Sim.

Nice pipe wheelman! Im digging the 49rr decal haha. Did you decide on gearing? With the malossi straight cut 7.98 gears i was able to cruise at 55 on the highway at quarter throttle. Why not give the extra head gasket a try? I was running remarkably cool at 320 wot 280 cruising and those were small jets i could have went even smaller on the jetting

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Back for an early Sunday Evening cruise-ride. Temporarily reinstalled the V8 due to clearance issue previously noted. With but 14 minutes on the meter at the start, and 45 at the finish, I didn't flog it. A nice wind-assisted top speed of 45 was seen nonetheless - at about 1/3 throttle - and top temp was 374. I plan to ride to work on Monday and Tuesday.

Good stuff wheelman!

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Finally got into making a video, thanks to Galaxy tablet. It ain't Fellini, but here's a heat cycle.

nice video and legs lol

nice video yes and legs no..
glad to see a good heat cycle done right ....
swimmingfree