MRC Forum- brought to you by www.morini-riders-club.com

Thanks for the photo harrymuffin - it helped me understand what you meant. After a long look at said photo, I saw that the rods are both facing the same direction, in other words the L/H or rear rod the wrong way round, which would lead to the same problem my engine has. I have just had a good look ...

Pete your generosity knows no bounds! I don't want to deplete your spares supply. On that one test ride I noticed how good the gear selection was - better than the Japanese contemporaries in the garage, so I think that the gearbox has got away with it. I do have to find neutral with my hand, but I p...

Thank you Ian and Mark, that could well be the cause of the problem all along. Whoever ends up with the pleasure of carrying out the repairs I will ask to measure the squareness. The 375 rebore was carried out by a company NLM used but it's possible the standard bore was also out of alignment, and t...

I have removed the front cylinder, which has survived. I roughly measured the side play on the conrods: the front 1.5mm and the rear 4.5mm! Perhaps this bike in it's previous life was poorly maintained and moved on when it gave up. For the record when I bought it there was also some electrical damag...

Finally got some time to investigate the problem, and it is what I had feared the whole time. The exact same failure as before, the gudgeon pin clip broken up and the pin allowed to drift and cut a groove into the cylinder wall. A newly rebored cylinder wall. Rats. IMG_0065.JPG Looking at the conrod...

Quick update. Tried a known good pickup and rotor in the garage, no test ride. No difference to idle behavior. Noticed oil on rear cylinder fins - thread of rear spark plug oily, and top of piston through hole looks wet. Electrode not wet - sooty like front plug (rich idle). Also, the tinkling rattl...

First ride in a long time today, and the rain wasn't going to stop me. I managed to fix the play in the pickup rotor with some thread lock, just to see if it made a difference. When warming up for an ignition timing adjustment she didn't want to idle with the 50 pilots so swapped back to the 48s whi...

Steve if we ever meet up I'll honour you on that pint! The Ebay listing was a pickup and rotor for a 250cc, and cost £75, which for that price I'm willing to take a risk. However that is a moot point as the parts are for a 250T. The play on the pickup is actually only less than 0.5mm, but I agree wi...

Really interesting reading the discussion. I was mulling things over at work today and I think one of the reasons I haven't made much progress with this bike is due to an unwillingness on my part to invest a lot of money in it, and instead trying and find what's going on with it using an exhaustive ...

When in doubt, draw a picture. The movement of the rear plate is stiff and rotational rather than lateral, but can't be helping. IMG_8219.jpg I checked the earth wire is still soldered on the pickup and also retimed the ignition to ANT at 6500rpm before making a couple more videos. Vid 4 https://you...

Firstly, thank you everybody for your patience, and contributing your expertise to this topic. I would call myself passionate about this bike, but some might say it's more like an obsession, the amount of hours (and petrol) I have spent in the garage trying to cure it. I've fixed other bikes in the ...

Decided to be thorough and ultrasonic cleaned the BS carbs, and rebuilt them including newly purchased o-rings and washers for the mixture screws - also added washers to the idle screws, which already had it's o-rings. Also blew all airways and chambers through with the brake cleaner. I am now confi...

I agree. In fact the last thing I did before I started this thread was take the bike for a ride. I can't go far because of Covid restrictions, and the bike is not yet road legal. On that last ride it seemed to pull well and carburate cleanly. Even the idle was more consistent than it was three years...

Update no. 5382! Moving on with John and Mark's comments about the brake cleaner and the effects of evaporation chilling the carb, I tried spraying parts where I knew there was no intake of air, and it still stalled the engine. The most obvious sign was just spraying the float bowl, shielding the re...

Thanks for the suggestions. The carb reducers/converters are indeed present and tight, as are the inlet stubs (one did need tightening earlier on in the investigation). I am wondering about the jubilee clips. I remember a long time ago NLM fitted them when I first took the bike to them, so I guess t...