gearing

[budge]

Hi, I bought my first Morini (1981 31/2 Strada) at the start of August this year as a non-runner but with advice from Mark Bridger on here I have got it sparking and running, I can't say it is running great as the carbs are in need of a rebuild kit as some of the seals are damaged or missing but it does seem to run fairly well but it just doesn't pull well and top gear is not worth the effort, this morning as I was getting ready to go out on my R75 I had a thought, could it be the gearing? I don't know yet what size front sprocket is fitted but the rear is a 40T so long story short what gearing should be on this bike? should it be 14-38? Many thanks for any help.

[Fastmongrel]

I would sort the carbs before doing anything with the gearing. I am amazed it even runs with damaged and missing carb seals

[Vitesse]

Blue book say 14/38.

[budge]

I would sort the carbs before doing anything with the gearing. I am amazed it even runs with damaged and missing carb seals

Hi and thanks for the reply, Carbs have had a good going over and been through the ultrasonic cleaner and rebuild kits will be ordered when I know what else I need to order.

[budge]

Blue book say 14/38.

Hi and thanks for the reply,
that's what I thought, going to have to get myself a blue book.

[George 350]

Hi,
While acceleration in top is nothing to write home about, it should be a usable gear.
I had a similar problem a few years ago, and it turned out to be that the rear cylinder ignition was not advancing.
To check this, you will need to add a "PMS2" mark on the flywheel - measure distance from ANT1 to PMS1, and replicate from the ANT2 mark. Doing this check should at least remove the ignition from the equation.
Otherwise, the issue could be elsewhere, e.g. exhaust or silencers blocked, air filters blocked, carbs not opening fully, brakes binding or rider has eaten too many pies!
Good luck,
George

[Fastmongrel]

Blue book say 14/38.

Hi and thanks for the reply,
that's what I thought, going to have to get myself a blue book.

You can download the blue book for free from the members only section. 150 pages iirc covers covers the pushrod v twins. If you want something a bit less comprehensive look on tinterwebs for a download of the Harglo manual.

The Harglo Manual http://www.morinist.dk/morini/harglomanual.pdf

[budge]

Hi,
While acceleration in top is nothing to write home about, it should be a usable gear.
I had a similar problem a few years ago, and it turned out to be that the rear cylinder ignition was not advancing.
To check this, you will need to add a "PMS2" mark on the flywheel - measure distance from ANT1 to PMS1, and replicate from the ANT2 mark. Doing this check should at least remove the ignition from the equation.
Otherwise, the issue could be elsewhere, e.g. exhaust or silencers blocked, air filters blocked, carbs not opening fully, brakes binding or rider has eaten too many pies!
Good luck,
George

Hi and thanks for the reply, I will work my way through all above and see if any help, but not giving up pies. I had my first reasonable run on it yesterday (60-70 miles) and it is getting better with every tweak.

[budge]

Blue book say 14/38.

Hi and thanks for the reply,
that's what I thought, going to have to get myself a blue book.

You can download the blue book for free from the members only section. 150 pages iirc covers covers the pushrod v twins. If you want something a bit less comprehensive look on tinterwebs for a download of the Harglo manual.

The Harglo Manual http://www.morinist.dk/morini/harglomanual.pdf

Hi and thanks again for that info, I will have a look at both.

[3potjohn]

If it won’t pull top with a 40t rear it’s never going to pull a 38t. Get those carbs rebuilt check carefully the jets and atomiser specs and verify fuel taps are free flowing. Check needles don't look too corroded or worn and no muck in the floatbowls. Eurocarb sell rebuild kits. Watch Paul Compton’s carb rebuilt video on youtube. Check ign timing. Check valve clearances. Make sure Plugs and caps are sound.
Best of luck chasing the issues.
John

[budge]

If it won’t pull top with a 40t rear it’s never going to pull a 38t. Get those carbs rebuilt check carefully the jets and atomiser specs and verify fuel taps are free flowing. Check needles don't look too corroded or worn and no muck in the floatbowls. Eurocarb sell rebuild kits. Watch Paul Compton’s carb rebuilt video on youtube. Check ign timing. Check valve clearances. Make sure Plugs and caps are sound.
Best of luck chasing the issues.
John

Hi John and thanks for the reply, received the rebuild kits today from Eurocarb and very fast service, I will rebuild the carbs tomorrow afternoon and see how that goes, I have played with the carbs and given them a good clean and it is getting better. I will check the timing again but one thing I have not done is check the valve clearance so well worth checking. I have been watching some of Paul's videos and watched the carb one again tonight. Good point on the gearing, the bike definitely isn't going great but I think I was comparing it to my R75 which I have been riding for years.

Thanks again, Budge

[Fastmongrel]

Make sure the seal at the bottom of the choke plunger sits in place and seals properly. I replaced mine but one of the seals became dislodged during fitting of the plunger and caused a lot of head scratching until I pulled carb to bits again and spotted the squashed seal.

[budge]

Make sure the seal at the bottom of the choke plunger sits in place and seals properly. I replaced mine but one of the seals became dislodged during fitting of the plunger and caused a lot of head scratching until I pulled carb to bits again and spotted the squashed seal.

Thanks again for your help and ideas, I got the kits and rebuilt the carbs and if anything it was worse, I decided to check the tappets and recheck the timing, both inlets were spot on both exes were a little slack ( not what I was hoping for) and the front tappet sheered with very little effort when setting the clearance so that was checking the ignition timing again a non-starter, so I thought I would check the compression, the rear is 160 psi and the front is 120psi, I don't know what it should be but to my way of thinking too big a difference not to investigate so I have now started stripping the top end off and it's not looking good.

[Steve Brown]

Oh dear, that isn't sounding positive. I will have a spare valve adjuster assuming your rockers etc are ok-mind you, I might have rockers to spare too. Don't get too despondent, these engines are fairly easily worked on and fixed if you can find the parts. And the parts are mostly available too. Let us know what you need and I'm sure you'll be able to sort the problems.

[72degrees]

What Steve said. I have spare rocker gear. It might just be in need of rings on the bad cylinder, though in my experience they will run surprisingly well with at least the oil control rings in multiple pieces. was there much coming out of the crankcase breather ?