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

Hello Lads,

The Supercharged Morini hopes to be ready for the 2018 racing season opener at El Mirage California in two weeks...

After much repair and refurbish in the off season, the Morini will be using a new timing belt I found.... Polymer body with kevlar reinforcing cords...

The Bike will be running without fairings this time out, and hope to set a new record for the class... I'll need to hit 108 mph to take the record.

Motor needs a bit of running to free up from the new bits installed...We'll see how it goes

Hope everything goes well.

Looks like the same belt I just installed on my K2!

Can you provide details of the fancy belt you're using please? might be great to try on my bikes too although they aren't going to work as hard as your one, I hope PS All the best for your attempt to break the record.

I'll hunt for the invoice where I bought the belt for anyone interested.....

I ran out of the rubber belts that fit well as they are too old and stressed to be comfortable using anymore....

All of the "new" rubber belt I've bought are too loose a fit compared to to old belts that were available.... timing would move around with them I'm sure

Robert in California

@smotorboy - yes please. I've just bought an old 3 1/2 Kanguro engine and it'd be a good candidate to try a new belt on.

Well guys, I'm finally getting back to you about the new belt that I have been running.

1- it works

2-it goes on-off easier than the rubber belts.

3- it needs a couple of degrees of spark timing lead to put the timing where you want it.
I'd say that the timing needs to be checked with a timing light at high rpm (6k) to know
for sure where the timing is with all slack pulled out of the system.

4- below is a link to the supplier:

https://shop.polybelt.com/124L075-Polyu ... 075FPK.htm

Well guys, I'm finally getting back to you about the new belt that I have been running.

1- it works

2-it goes on-off easier than the rubber belts.

3- it needs a couple of degrees of spark timing lead to put the timing where you want it.
I'd say that the timing needs to be checked with a timing light at high rpm (6k) to know
for sure where the timing is with all slack pulled out of the system.

4- below is a link to the supplier:

https://shop.polybelt.com/124L075-Polyu ... 075FPK.htm

I get mine from a garden lawn mower stockists and have had only one genuine Moto Morini belt break- no damage occurred, I could not understand why the engine stopped after checking the usual, only when I took the rubber cover off did I notice the belt was broken. Fitted another and away she went.

does the team think that this poly belt is the way to go?

Not in my opinion. I use £5 belts from RS Components. Made by Continental. Proven at Cadwell!

MickeyMoto wrote:Not in my opinion. I use £5 belts from RS Components. Made by Continental. Proven at Cadwell!

But, but did you dyno test it with that belt and exactly the same state of tune but with a Kevlar belt ?

The 'timing moving around' concept is intriguing. Though I'd have thought that once a Morini strobe timed properly was WFO at the red line it wouldn't make much difference, until the belt started to wear significantly perhaps, in which case regular strobe checks would be in order.

Er, no. Mine makes not many horses, so not tough on belts. If I was tuning it to a few more bhp I would, but in my opinion why pay extra for something that works? Been in Yorkshire too long. The squeaking is not my boots...

If the belt is worn significantly, change if for another £5 one!

MickeyMoto wrote:Er, no. Mine makes not many horses, so not tough on belts. If I was tuning it to a few more bhp I would, but in my opinion why pay extra for something that works? Been in Yorkshire too long. The squeaking is not my boots...

If the belt is worn significantly, change if for another £5 one!

MickeyMoto wrote:Er, no. Mine makes not many horses, so not tough on belts. If I was tuning it to a few more bhp I would, but in my opinion why pay extra for something that works? Been in Yorkshire too long. The squeaking is not my boots...

If the belt is worn significantly, change if for another £5 one!

Well yes, but quicker to do a strobe check in the paddock

I hear what you say, but smotorboy reckons even new ones are too loose on his machine (perhaps he needs new pinions ?). I'm not sure the bhp to be released by this strategy on any Morini would be enough to notice anyway. I like the 'easier to get on and off', but given the trend in the sterling/dollar exchange rate a Kevlar one from the USA is going to become even more HFM? If only Gilera Nordwests and Saturnos used lawnmower drive belt sized cam belts.

I once ran a belt long enough on my Sport that it was over the maximum 6mm slack limit and the idle was getting quite unreliable.

The idle was much more stable as soon as the belt was replaced, but the timing jitter at full advance didn't seem to change.

The camshaft pulley of course came in three grades, A, B and C to enable use of sorted and graded, rather than selected belts. Selected belts would have been quite expensive.

That doesn't mean there were three distinct sizes of camshaft pulley (or belts), there would have been size variation in each grade. A small B grade pulley paired with a long B grade belt might be slacker than ideal.

I've seen a tensioner pulley mounted to the back of a specially made alternator stator plate. The plate could be rotated on extended adjustment slots to set the tension.