As you are aware I just purchased my 75 350 sport last week.
I took it to get registered the other day and after a few minutes of it running I saw what looked like a black liquid coming out of the balance pipe join. At first I thought it may have been oil but it is more like water and carbon.
I also hear a tapping noise coming from the front cylinder.
My bike has 46000kms on the clock and am new to Morini, so any assistance on what these issues are and how I can fix them would be greatly appreciated.
black stuff from the exhaust system: if you only drive around the block a lot this is usually condensation with carbon because the engine never gets warm enough. Otherwise, no idea..
Tapping noises: pretty normal for a morini but is it much louder then the rear cilinder? May you should check the valve clearance on both just to be sure
The bike has been sitting around for the last couple of years and never ridden regularly. So having said this perhaps moisture has gotten into the tank.... I may drain the tank and put in new fuel and filters and see if that gets rid of the black liquid.
In relation to fuel, can I just use regular or premium unleaded or do I need to add some sort of additive?
If the bike has only had short runs then combustion products including water will form,being discharded via the breather pipes like brown mayonnaise, or as you have seen black water in the silencers.I'd check the tappets on a cold engine to put your mind at rest re the engine noise at least in the first instance.Some noise is not untypical.Also a thing to aware is that the rocker block studs can easily be pulled out of their threads, but these don't need disturbing just to check tappets.
Regarding petrol, Morinis will run on premium or standard unleaded. I like to use Shell V-power or Total Excellium which (I believe) are ethanol-free. I also treat the bikes to an occasional tank of leaded four-star, which has them cracking along very happily.
Hi - are you sure the bike was running on both cylinders - I have had a black liquid which i believe was petrol and carbon come from the exhaust thread when I had problems with the bike not running on that cylinder. - Duncan
Check the tappets, maybe change the oil to 10-40 semi synth if you don't know whats in there,
don't worry about the dirty water mine if left ticking over soon as a little puddle under each
silencer, the dirty water will most likely change to clean ish water after it's been run enough
to blow any old soot and such out of the system.
Air cooled engines can sound a bit noisy, Morini's are not bad in that respect, you could do
with hearing another run get a idea if yours is worse.
I will have a look in the next few weeks and see how I go. I am waiting on a workshop manual from NLM.
I was wondering if anyone can send me a vid of what a standard 75 sports engine sounds like so I can compare the two. If anyone has any vids could they please email me at Ponch1972@gmail.com
I sent a vid to Stuart from NLM and he reckons it may be the primary gear. Sorry to ask a silly question but what is the primary gear?
The black water would be condensation, my guess is the bike has been sitting and the carbon has been washed out with the condensation.
I would be going over the bike, check tappers, lifters etc and then change oil, plugs, cam belt, check tyres, timing, also check your suspension oils in the forks and rear shocks etc.
I run mineral oil (Penrite Premium 20/50), only and change it every 4000km, although I would be changing the first lot earlier after solid run, also clean and wash the filter.
Fuel I run 95 premium with a squirt of the lead additive.
Further if the bike has been sitting check your carbies, the needles and seats etc as the Dellorto carbies internals will corrode with time if not used regularly. Flush them, clean them and if necessary get a kit to replenish them.
Also double check all nuts, bolts any fittings, ensure they are tight and if necessary use the blue loctite, believe me nothing worse than looking for lost parts when out riding, use rubber washers when you can particularly on the side covers and seat screws also the dash warning lights. Do this on every ride during and after.
Good luck, drop me a line on my email via pm and I will be in touch.
Cheers
Brett
1974 Moto Morini 3 1/2 Sport
1940 Indian 741
1942 WLA Harley Davidson + Sidecar
1970 Laverda 750 GT
1973 BMW R60/5
2012 Harley Davidson Road King