Le mans needle position

Ok, I’ll try to post guys… having trouble logging on to site. Had a question about the needle position on the le mans 2 carbs…they were in the 4th notch when I got it and it ran fine but wouldn’t rev past 5000rpm (about 90mph).I had it on the second notch a while back and it tended to shut off when I closed the throttle, so back to 4th…Have gone back to 2nd notch and not tried bike yet but would there be a reason why someone had done this? It was running rich, black plug etc…slides are bit worn, k and n’s fitted. Mistral exhaust when I got it but now lafranconi cans. All jets standard.

Well with K&N’s fitted the reccomendation is up the main jet 10-12% I found Tim Hicks and also Eurocarbs real helpful.

According to Guzziology the standard setting is, as you say, 2nd position from the top.

When I fitted K&N’s I increased the main jet by 10% and lifted the needle one notch.
Have you had a look at the jetting in the carb? Maybe someone’s tried to compensate for the mods by just moving the needle rather than re-jetting?

Standard jetting is

Idle 60
Main 140
Needle K5
Needle jet 265
Slide 60/1
Choke 70
Pump 38

Hi GTM…Needle is K 20, main jet 140… I have it in the 2nd notch now but have to fiddle with the mixture screws to get it to idle… Have not tested it high speed yet but with the needle in 4th bike only reached 90mph and died. Have thought of bigger main jet alright, perhaps this would cure it? Motivlack2013-12-10 12:50:53

Ok, I see the needle should be a k5! Is this the problem? Why k20 with everything as standard?

The settings I gave were from the tables in Guzziology.
It is not unknown for Guzzi to change specs mid production but if you’ve got a problem it might be an idea to put everything back to standard and start from there.

Great thanks …So your le mans (2?) has a k5 needle, 150 main jet and needle in 3rd notch with k and n’s?? I will order the correct needles and two larger jets if that’s the case. Anyone else have a le mans and what carb settings?

I don’t have a Le Mans. I have a Cali III FF. The settings I have given you for your bike come direct from the tables in Guzziology. The bible for Guzzi owners.

Thanks, have guzziology, I’ll take a gander…

If you were ordering from Eurocarb, then you could ask them what the difference is between the two needles.

I would give Eurocarbs a call they know their stuff and will save you lots of hassle BUT + 10% on standard main jet = 154

I know it made a fair difference to the T5 850 engine alot cleaner pick up and a slightly higher top speed BUT the top speed on MY V1000 is more limited by the high ratio bevel drive from a Convert BUT it is OK fo the V1000 as I really do not want to be over 85 fully loaded anyway.

It has a higher top speed in 4th than 5th. The 1000cc engine is being recommissioned slowly for next year THAT will pull the top gear alot easier. It has at the moment been cleaned had the mains checked, new rings the valves re ground, new seals and will have other new bits as and when, I want to get it all done before Easter next year.

Thanks GB…I’ll give them a call tomorrow… Good luck with the 1000.

Reading this set me thinkin, didnt mk 2 come with bell mouths ? , so fitting k n ns would not require bigger jets , slightly smaller if anything. Standard needles only have 3 notches I thought ? Will have a look later. My mk 1 has always been best with the needle at its highest. Worn carbs can cause lots of problem for sure. We also find that the screws need fine tuning, don’t go by the ‘1 and a half turns out’ etc.
Fitting big mains also kills em in our experience, a couple of years ago, we aquired a spada royale which topped out at about the ton, was a bit vibey etc. On investigation it turned out somebody had put 175 mains in it !
The smallest mains we had in stock were 142 s I think. Popped these in and voila, problems gone.
Eurocarb are very good btw.

Always worth having the carbs set up right.
Kate’s right in saying that the LMII had bell mouths as standard.
The carbs are, of course, only one piece of the jigsaw. Tappets, points (if fitted) and timing all conspire to make the bike really good or really awful.
Kate makes a good point about making sure of the baseline for a MkII. Once started to put a poor running Spada III back to standard jetting etc. when I double checked the spec and found that it was fitted with non-standard carb bodies;-)
Best of luck
Steveguzzibrat2013-12-11 15:45:18

Hi guys. Thanks for taking the time to look at this. I rang Eurocarbs today and they were very helpful. The guy I spoke too said the reason for the K20 needle as opposed to K5 standard may have been to allow for the more free flowing Mistral exhaust system. He told me to play with the needle in different notches and make note of changes. I was aware of the stock le mans running bellmouths so I did question the need for a larger main jet, hence the previous owner having the k20 needle in the 4th(highest position)
I am sure timing is bang on etc. It does have a 950 big bore and I changed the silencers for Lafranconi competizione(using the mistral downpipes) Electronic ignition also fitted.If any of this would make a difference.
It does feel like carburation to be honest. Bike runs ok up 5000rpm and dies. I do have a spec sheet from the guy who cleaned the carbs and noted as ‘defects’ were worn slides(both)Needle jet fibre washer questionable(left carb) and may lead to flooding. Any ideas. I have loaned out the ignition box to friend who is trying to get a Triumph running so wont get to play around until closer to the weekend. Would love to get this sorted and put it to bed.

On a side note I gave the previous owner a call to pick his brain and he said he never had the bike anywhere near 90mph+!! Come on, its a le mans and needs to ridden fast…:wink:

Bike in question. Top speed 90mph

Sean, you’re saying that your engine will not rev above 5,000 rpm and 90 mph.
Do you mean in any gear or just top gear? If just top gear, it will be on a full throttle (I assume) and then only the main jet will come into play.

Try doing a plug chop after (hopefully) holding full throttle for half a mile or so preferably on an uphill gradient.

Your bike looks ace by the way.

I’ll second that…

Some elektrikery ignotion does not allow the full advance…just incase you come up against a brick wall with the carbs, That bike should be good for 130+

Two other things come to mind as well after the ignition timing is checked.
Are the chokes definitely “off” when they’re meant to be.
Has the engine been apart? If so are you sure that the cam timing is correct?