Idle rich

[Cliff]

I'm trying to tune/sync the carbs on my '78 Strada. I can't seem to get it to idle at anything below 1800rpm. Is this right? It seems a bit fast to me. Searching around the net and the original Harglo and NLM manuals for the correct idle speed has drawn a blank!

I remembered I had a old Gunsons colortune kit and dug it out of the loft. I ran the test on the front cylinder. However, the idle screws seemed to have no effect on the flame colour. It remained yellow which according to the instructions means it is too rich. My thinking is that because the idle speed is so high the idle circuit has no effect! Any thoughts much appreciated.

Cliff

P.S. I haven't yet carb synced with a gauge of any sort. I've been looking at home made manometers on the net. It seems a simple enough idea using plastic tubing, a board, adaptors and TQF oil. Has anyone had a go at this? Be great to avoid spending £65 or so for a Morgan device.

[Ralph]

Have you checked the jets are tight and the O rings that seal the slow running jet as it goes into the
float chamber are in good condition also the seats and seals on the choke units, you can get new choke
units from P&M tuning at Middleton nr Morecambe they have a web site.

http://www.pmtuning.co.uk/dellorto-manu ... -vhsb-vhst

I think these are they.

[mad muller]

have you got the slides in the right way round, the cut outs facing outwards check this first, check the cables are not set to high as to lift the slides as this will take it off the idle circuit and mixture screws will have no effect. also check ignition timing isnt to advanced. hope this is of some help. muller

[chirpy999]

From what I know about the instruments on a morini I wouldnt trust the revcounter or speedo to be very accurate . My sport idles at 2000 rpm according to the rev counter.As anyone ever connected a trustworthy reliable rev counter to a morini and got a proper reading of what the revs are at idle?


Also my speedo seems to stop working at about 120 kmh, I am giving her morew revs in the gears now but get to 120 knm and the needle just seems to wobble at that speed.

For a smallish outlay Koso do a multi function electronic speedo /revcounter with loads of warning lights . Youd have to be pretty proficient with electrics to wire it in and fabricate a mounting bracket.

On the subject of low speed running heres the situation on my bike with regards to the elecric starter. Use both chokes and shell fire up on the starter go for a bit of a spin stop and try restarting , the starter whirrs but no fire. Yesterday started first time from cold went for a ride to NLM tried to start her on the electric starter whirrs but no go , give her choke and she starts!!!! Is that a sign of being weak on the primary circuit or what!!!

[Ralph]

My rev counter reads about 50 rpm low according to a calibrated mechanical rev counter,
the speed'o reads about 5 mph fast I thought the rev counter was reading low and so revved it
higher but testing proved otherwise.

http://s235.photobucket.com/user/G7ied/ ... sort=3&o=1

[EVguru]

It won't idle reliably below 1800, or you can't make it idle under 1800rpm?

You must some have free play in the throttle cables. When setting carbs up from scratch I like to have lots of slack to start with.

If the ignition is retarded then you may have to screw in the throttle stops to the point that you're off the idle circuit and onto progression.

You should be able to make a cylinder cut out by screwing in the mixture screw.

I've never seen a choke fail to seal except when the rubber is actually missing from the end.

Morinis often run rich on modern fuel (leading to a stumble coming off idle) and benefit from a smaller idle jet.

[Ralph]

I've never seen a choke fail to seal except when the rubber is actually missing from the end.

I have it ran like a dog rich as hell.

[Cliff]

Thanks for your advice one and all. Mad Muller when I read your line about the slide cut outs being in the correct way round it rang a bell It's too late now to go and check but I think this is what I've done Pretty sure it's not the choke or jet seals as I renewed all these in the rebuild.

I know the tacho is a bit vague and like almost every Morini instrument pointer I've ever seen mine too has a kink in it ( caused by heat so I'm told) which means it gets stuck on the glass before it gets to zero

I'll report back with the results of further investigations!

Cliff

[Ralph]

I know this is a old thread but on my Strada it ticks over better if the plugs
are gapped at no less than 25 thou.