berkshireduncan

it's more to try and squeeze a little more 'plonk' out of the bike- for mud & inclines..

Hi all, Anyone have any experience / advice to share on adding flywheel weight to small four-strokes for trials..?

Bashplate's been fitted since the pics were taken- just need to mod the rear brake pedal and we're away. Pipe is a Sammy Miller TL job, so it does sound pretty good (..for a 125!)

Hi all, I've just about finished my Honda 125 Special, and I'm aiming to do a couple of events in the New Year. I came back last year after a 25 year layoff and did a few trials- but with hindsight, perhaps a Monty 348 wasn't the best / easiest bike to start back on..(!) (Sadly) that's now been sold on to a younger, fitter owner- but I do love a project, so I built this bike up over the Summer.

Thanks, feetup. I had my stator repaired by Steve at Bradford Ignitions, and followed your guide for re-timing. The bike's now starting and running well, so I'm back in business. Interestingly, the timing had been set pretty well advanced at maybe 2.2 - 2.6mm BTDC, so it'll be good to see how the bike feels and rides now. Thanks again all.

Thanks Feetup.. that makes perfect sense. P.O. did a (Motoplat) Electronic upgrade, so it's just a case of working out / marking up the flywheel at 17.30 degrees BTDC as you say, then lining up the stator behind with a drill bit through the timing hole in the flywheel.

Thanks, Kingscorpion (Rookie?) question.. when you're setting the timing against piston position BTDC with an old school 'drop in' TDC gauge, how the heck do you accurately adjust in increments of as little as 0.2mm when the gauge scale is 1:1 with the piston?

Does anyone have a spec, or known-to-work setting? .. I'm guessing the timing's set in mm of piston stroke BTDC, rather than degrees BTDC on a crank dial gauge? Thanks

My best bike noise by a country mile was a Guzzi 1100 Sport (carb) with carbon cans. I used to do early shifts, so I routinely rolled down my sloping drive and coasted 100 yds or so down the road before firing it up to avoid upsetting my immediate neighbours. Went on a Boys' road trip to Normandy / Brittany and my mate got the royal hump as everywhere we stopped, no-one gave his new 916 a second glance. Like Peter, I'd have to say a Buick / Rover V8 takes some beating- I've owned, loved and lost both a P6 and a 2-door RR Classic. Ah, the fuel bills.. My reverse trike only has a 50bhp VT500 motor; but with a 9-10k redline and a fabricated race pipe, it wails!

I gave up on finding an internal puller to fit, and went with a 3-leg. It's very slightly dented the brass weighting ring, but I doubt it'll significantly affect balance. Stator & coil are away with Steve at Bradford Ignitions, so hopefully I'll be trialling again soon..

Losing the will to live here.. My mystery 348 Motoplat electronic rotor doesn't take a 'Montesa standard' 30mm puller- and the 26mm x 1.5mm R/H puller I just ordered is fractionally too small. Aaarrgh!!! I don't want to use a 2/3 leg puller, for fear of messing up the sweated-on weight band, so before I try for third time lucky and order up a 27mm x 1.25mm R/H puller from BVM, has anyone got any further suggestions or input? The P.O. tells me my Mini 6 is 'the same as fitted to a Villiers 210 kart engine'.. although I haven't managed to find any rotor / puller specs for same online. Q) Has anyone ever come across a Motoplat rotor with a L/H thread- (or is the BVM unit likely to be correct) Thanks again in advance..

Thanks, BogHopper The P.O. kindly got in touch and confirmed the spec. It has a Mini 6 set up- from a Villers 210 classic kart (the UK's longest running kart class, apparently) Luckily, my online researches had led me to a 26mm x 1.50mm R/H puller, which I've already ordered and is on the way. The P.O. had a whacking great brass weighting ring turned up and sweated onto the rotor; and IMHO the bike has bags of bottom end grunt. Thanks all

Hi Kingscorpion- thanks for the tip. There's no reason to believe the rotor & stator came from another Montesa- presumably just some other 70's/80's European bike. Steve at Bradford Ignitions ('Motoplat UK') said the same thing- that the Mini 6 was maybe a little light for a trial bike- I guess because it was originally fitted to an Enduro / MX.. however mine has a heavy brass 'wedding ring' band sweated onto the outside of the rotor to add some weight. You said 26mm.. 1.5 pitch and Right Hand thread..?

The Sammy Miller one I have isn't.. but is 27mm the only 'other' Motoplat size..?

So.. I ordered a 'Montesa' rotor puller from Sammy Miller, which is (by my measurement) 30mm. However, my 348 has had a number of upgrades over its life, including a Motoplat Mini 6 Electronic ignition.. which I'll be posting off to Bradford Ignitions as soon as I can get the rotor off.. The crank end makes measurement in-situ with calipers tricky, but I make the internal thread size about 26mm, so I guess my question is: Did / do any Motoplat Electronic rotors come with puller thread sizes close to (either side) of 26mm? In other words, am I safe buying a generic 26 x 1.5mm puller- or could my mystery rotor possibly be 25mm- or 27mm, etc..? Duncan