Moto Guzzi V50 Starting on 1 cylinder

[Ronb]

My V50 III tends to start on one cylinder from cold and then after about 30 seconds number 2 cylinder chimes in and the bike runs fine and the engine revs through to the redline.
It has new points condensor, plugs, the valve tappets have been set and the carbs are clean and ballanced.
There is no lack of power when running.......
Where do I look next to solve this?

Ronb   

[chaterlea25]

Hi Ronb,
What sounds a strange problem may have an easy answer??? 
Do you leave the bike parked on the sidestand while its in the garage?
Even with the fuel off, (those taps arnt great) one cylinder can flood sometimes
Try parking on the centre stand, and check those taps for drips
My T3  behaved in a similar fashion

Cheers
John

[R]

Something else to check is that condensation in the fuel can lead to a little bubble of water in the bottom of the floatbowl, again usually on the sidestand side. Until it gets sucked up with some revs, seems it can make starting awkward. Some models of DellOrto seem to specialize in gathering rainwater while riding, don't know about the V50 ones...

Always worth doing a compression test, part-worn rings or valves can do this when cold, but then run prefectly.

[JFerg]

I rode my Monza for 18 years, 100,000 miles and loved it.  Loved it even more after I begrudgingly replaced the points with a Dyna system.   I am no fan of electronic ignitions, in fact I refuse to have a vehicle that is smarter than me.  Everything I own (5 bikes that get ridden and two cars) has either points or magneto ignition.  And carburettors, of course.

Problem with the V50 is fairly deep rooted.  You'll notice that it does not start while cranking, but will fire at the instant you release the start button.  This is because the voltage drop caused by the starter cranking means a feeble and inadequate spark.  Release the button, volts come back, ignition comes back.  I never did find an explanation for why it ran on one until it felt like using both.  Rev it when it's on one, the second comes in, close the throttle and it's happy on two.  Start it hot and both cylinders play.

It was only in despair that I tried the Dyna, and it transformed the bike.  The merest glance on the starter button and it was running sweetly on two.  Actually ran better all round, but best of all it eliminated any future need to get at the end of the camshaft, between the pipes and behind the front 'guard.

It hurts me to say it, but the best solution is a decent electronic ignition.

cheers,
JFerg

[Ronb]

Thanks for replies so far.
Comments:
- I was pleased to hear I wasnt alone with this issue. 
- I always park up on centre stand so that is probably not the problem
- Water /condensation in fuel interesting .....but wouldnt that effect both cylinders
- Retrofit electronic ignition .........interesting idea and as my other bikes are old, slow reving single cylinder and power up by magneto I could go hi tech and minimise future maintenance. I use an "Odesey" battery so power should not be a problem.  But which electronic ignition is best and where to get it from?
- I did wonder about the HT coils as this is the only bit of the ignition system I havent replaced. Anybody got any views on replacing these as a solution and with what?.
The original equipment is bosch (I think) and second hand replacement probably not a good idea given that they will be circa 20 years old.

Any Thoughts

Ronb       

[R]

Easy to test some of these.
Take off the floatbowls, and see if there is water or grunge lurking.

Its also not too difficult to try a separate battery to power the starter, although obviously you need a good battery (car ?) , and some cables to allow this.
Be careful that the connections are correct + or -, and shielded so can't short anywhere or anything. Only the heavy cables for the starter need rearranging.

Can you switch the coils around to see if the problem swaps side. ?
If you don't have leccy ignition, have you tried removing a plug lead and trying to start the difficult side only ?  This can sometimes identify where the trouble is, by getting everything spot on. This can be as simple as a throttle cable (or choke) not quite engaging enough to give a good starting setting. (Are the throttle cables perfectly synchronized ?).

Hope this helps.

[JFerg]

Ron,

Cleaning the float bowls out is not a bad idea, but it's not the real problem.

You can replace the HT coils, but then you'd be like me and have a perfectly good pair of HT coils in the shed long after the bike has moved on.

I fitted a Dyna S, because that is what was recommended in Dave Richardson's legendary tome "Guzziology".  It's a points replacement only that retains the centrifugal advance and the same coils.  I always carried the original points and plate, wrapped in plastic and tied under the tank, just in case.

Like you, I have slow revving singles with lovely proper magnetos, but I also have a brace of LeMans IIs, which are perfectly happy on points.  Not only is that a more robust ignition system, the big blocks have their points in a housing (often wrongly called a "distributor", because it sort of looks like one) that sits in the valley between the cylinders.  It's easy to get at.  No-one would ever say that about V50 points.

The other thing that makes a huge transformation to a V50 is a conversion to tapered roller bearings in the steering head, replacing the vintage loose balls in a chattered race.  I can send you the drawings if you like.

cheers,
JFerg