Dizzle ma Nizzle

[smegballs]

So my MZ is perfectly fine cycle parts but a fucked top end/ engine.....

So I might see about using it for the basis of a diesel bike.

Looking on ebay there seem to be yanmar clones about 8 hp or so around the 250-300 mark. Hopefully get a 2nd hand engine and maybe save a bit.

So I'm thinking of transmission, I know you can get all happy with torque converters and old pre-unit gearboxes, but I'm thinking more single fixed gear ratio along the lines of centrifugal clutch on the output shaft, with a inital belt reduction drive then a further chain and sprocket reduction to the wheel.

Now this thinking is on the basis that my 1.8 hp, 50cc mobylette two stroke could pull 0-30mph with basically the same set up.

No variator so a fixed gear ratio all the time, now if a 50cc two stroke - not the torqueyest thing going - can pull 0-30, how does a 8hp, 400cc diesel sound pulling about 55-60 top end speed?

Another front is sorting DVLA out with new fuel/engine etc etc, will the bike need VOSA checks or engineers report etc etc, insurance costs etc etc.

Also an alternator will be required for power generation....

Any ideas from people with similar experience needed!!

Rich

PS: If it goes ahead there will of course be a devoted thread to the build.

[Endless Nameless]

I imagine you will have issues because the 50cc 2- stroke will have a much greater rev range than the diesel motor (genny engine?) which is almost certainly very low revving.

Might be wrong though.
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A2 passed 22/07/08; restriction up 22/07/10 (just so I don't forget)
'79 Suzuki GS550E. Yes, that's a GS550, not a GS500.
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[MaybeGuy]

your MZ now has the 250 top end back on, plenty of compression, and is done properly (unlike your 300 top end, you 'tard).

just sort out the electrics, then let me set it up properly so it actually works.

your 300 probably seized because its perfectly smooth. it didnt get honed.
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[ms51ves3]

[smegballs]

My mobylette didn't have a variator!!!

I know some did but mine wasn't one of them!!

At the revs, the mobylette, being long stroke, was rated its 1.8 hp at only 4.5k. I did a bit of reading and although most generators are rated for a continuos 3600 rpm, by removing the governor and throttle stops they can run at 4200 safely.

Given that I have:

Engine cc Fuel Power Rev Range

Moby 50 Petrol 1.8 0-4500 rpm
Yanmar 441 Diesel 8 0-4200 rpm

From this I'm gonna assume that the diesel will certainly pull 0-30 .

I suppose I could even work out the gearing for 30 and then steadily try different sprockets until it found its top speed/driveability equilibrium point, expensive in sprockets tho!


PS, mattspratt did you have a wiggle on the conrod when putting the 250 on? Do you reckon any of the bottom end bearings are shot?

[MaybeGuy]

your cranks fine. with the 300 top end you could move the crank about 2 degrees without the piston moving. why you ever ran it like this is beyond me.
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith