Unleaded Fuel use in Morini V-Twins

[robinh44]

Hi,

From what date were the Morini V-twin engines adapted for unleaded fuel use or do they not need any adaption. I have a 1984 350 Kanguro, previously on an 81 Triumph Bonneville I used the 'broquet' product that seemed to work well on that bike.

Regards

Robin

[Coxey]

Robin
I use Castrol lead replacement fluid - I can't remember its exact name, but it costs around 8 quid and seems to last for ages - a small squirt per tankful
Rob

[robinh44]

Hi,

I will play it safe then and use the Broquet device, they worked well on my Triumph and probably still are for the current owner. I am not keen on additives at each fill-up reminds me of the two stroke petroil mix days, just another thing for me to remember ( which I will end up forgetting).

Regards

Robin

[buzby]

Hi Robin , the Broquet website claims all sort of wonderful features from this product, do you agree and over what mileage have you used it? cheers, Dave.

[Guest]

Dave

I used it in a 1981 Triumph Bonneville over a period of about 18 months back in 1998. Running the bike just on unleaded with no modifications. I cannot vouch for the octane boosting or mpg improvement, just had good starting and fuss free running ( other than the usual oil leaks, and normal triumph issues, clutch & carb related). If my 1984 morini engine is not suitable to run unleaded then I will give these devices a go again, I prefer the fit and forget method of dealing with unleaded fuel. Any other tips or advice on running unleaded on morini engines welcome.

Regards

Robin

[robinh44]

Dave

Sorry forgot to mention mileage, over the 18 months was not a particularly high mileage about 6000 miles.

Regards

Robin

[SupermotoDave]

As Morinis were sold in the US where they have used unleaded for years, and we are not talking about the personal milage of Captain Kirk, I have never taken the slightest notice of unleaded / LRP and just run unleaded, with the occasional tank of super as a treat.
The MRC used to recommend that people ran the bikes on 3 star and not 4 star(many years ago) as they did not need super high octane fuel.
There is also a bit about unleaded on the NLM website if you have not seen it.

[RedVee]

I've been running a variety of morini's for years on unleaded without any problems what so ever. In fact at one stage when some one gave me a can of leaded for the strada it absolutly hated it!

[robinh44]

Hi,

Thanks for all the tips & advice, you can't beat owners direct experience. I checked the NLM unleaded page but it seemed to be confirming that you need a valve/seat conversion. I will probably get the broquets and be the guinea pig for the group.

Regards

Robin

[Steve Scott]

I've been running unleaded fuel in my '79 Morini without additives and without issue for about 32,000 miles. Mine is a 500 but I can't believe the valve seats are any different than the 3 1/2's.

[robinh44]

Steve

Thanks for the info, in the US what octane rating is your unleaded, in the UK we run at 95 for normal or regular unleaded going up to about 98 for premium.

Regards

Robin

[Steve Scott]

Thanks for the info, in the US what octane rating is your unleaded, in the UK we run at 95 for normal or regular unleaded going up to about 98 for premium.

Robin,
All grades of pump gasoline sold for road use are unleaded here, and have been in most areas for about 20 years. Comparing octane is a little involved because our posted octane numbers aren't the same. We use an average of the Motor Octane Number and the Research Octane Number, while in the UK you post the Research Octane number alone. A modern fuel will test about 8-10 points higher using the RON method than the MON method. The result is that your posted octane number runs about 5 points or so higher than ours for the same fuel. I find that my Morini is perfectly content to run 89 (MON+RON/2) octane unleaded which would be about 94 (RON). This should equate to your regular petrol.

[SteveMRC]

I seem to remember that all magazines who tested the broquet and other similar 'drop in the tank' products came to the conclusion they were all snake oil remedies and advised readers not to waste their money.

All US Morinis have run happily on unleaded for decades. I have run mine on plain 95 octane unleaded with the occasional treat of 98 for years with no apparent ill effect.

Steve

[Steve Scott]

Something to consider is that the most likely problem to occur when unleaded fuel is burned in an incompatible engine is exhaust valve seat erosion. This would cause the valve clearance to close up over time. Since It's relatively easy to whip off the rocker boxes and measure clearance on our Morini's (especially the 3 1/2 where there's a bit more room), just check it more often until you're content that everything's OK.

[robinh44]

Hi,

Thanks to all for putting my mind at rest, I feel happier using unleaded with no additives now. The tip about checking valve clearances on a more regular basis is a good one.

Regards

Robin