Ok, so i got his bike and it went 20mph.
I put a high compression head on, it has a 15/15 carb, a biturbo, 11th front sprocket and 45 or 46th rear sprocket. I also bored out the intake port to 14mm, exhaust to match biturbo, trimmed all gaskets, drilled out intake manifold. Polished exhaust port and roughened manifold/intake port. Why am I only going 25 mph? I believe the jet size is 58 or 59.
Any thoughts, other than that biturbo's suck?
How much compression are you putting out? How fast was it supposed to go from the factory?
They're not supposed to be fast from the factory (maybe 25mph tops), hence the modifications and aftermarket parts. Compression is pretty good, i don't have a gauge, but it's definitely not low compression by any means. This is also one of the NOS ones form '77 mopeds, and assuming they were assembled properly, there shouldn't be any bad gaskets (crankcase) or weird air leaks.
Dan I would say the harden seals in the crankase too. If you buy the right files and rise the tranfers and exhaust port (3-5mm).
There is so many mods for the minarelli v's... clutch springs, drilling the shoes, polishing.. the inside of the case.
This is a NOS motor from the 70's?
I would disassemable and reassemable just because I don't unless I put it together. Its just me. Its a safety thing.
The big thing is to find a C2 motor.
check the timing, I just found that the timing on my city bike was stupid retarded. I got better throttle response and a few more MPH's. It only did 20 when i got it. now its much closer to 30, not verifiable though faulty speedo
the minarelli v1 engines came in a 25mph and 30mph version. it could just be that you got the 25mph. the difference being that the cylinder/piston are a little smaller, the intake port is a little smaller and the intake manifold is a little smaller.
Ed, harden crank seals?
And yeah, it's obviously the 25mph version.
Ed, you seem to be pretty on top of the minarelli game, what do you prefer to do as far as drilling clutch shoes goes (as in sizes and numbers and locations of holes)?
The timing is good on it, i suppose i could get an oversized piston and have the cylinder bored out.
I'd really like to avoid splitting the crankcase, as I do not have the tools nor time to invest into that right now.
I would like to do everything possible before checking seals/bearings/case gaskets/case polishing.
Thank you for your kind words. Harden crank seals.. The rubber seal is stiff and harden from over years of sitting. Drilling the clutch shoes makes them lighter and quicker to grab open.
Any stock cylinder can be drilled, ported and filed. You might wanna get a 15mm pbhg a tuneable carb in the future. Any pictures of this bike? Running Cdi on this?
With the piston at tdc and carburetor off (I put a rubber hose on the intake and blow in the intake and listen for leaks).
All my italian bike have 42 or 44 rear sprockets, 11 is a good gear for the front sprocket.
Any body else.. ? I would look at the ports in the cylinder show the group. Decarb everything? Ed
No cdi, i'll try a 44th rear sprocket. very minimal carbon buildup (only maybe 500-600miles). I'll get pics of the bike and ports later. the dellorto came with the bike, not my first choice in carbs, but it was free.
And ed, i'd still like your email if you don't mind. I have another minarelli "project" i think you can help me with, but i don't wan to spam up the boards.
dan, we're totally fighting.
Uh oh.
bj at handybikes.com is the go to guy for minarelli parts.
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