Opinions on the factory B10 camshaft

Hi, I have just fitted the 950 kit to my 850 Le Mans and was considering changing the camshaft to the factory upgrade B10 cam, I was wondering if this is a worth while modification and if any of you have used this cam with any success, any comments are much appreciated, cheers Chris.

Go for it…

You should also get 4 new followers for it if you do, cams and followers wear as a set, the followers tend not to like being made to work with a different cam afterwards. Guess how I know! (And I was told to use new ones, but ignored the advice.)

I have already bought new followers and push rods, the reason i bought new push rods is when i put them in my lathe they had a run out of about 1 to 5mm so i replaced the lot! When i received the new rods i found they too had a run out of about 1mm so they aren’t great to start with!, I may remove the cam for close inspection but it means undoing all my hard work with the timing chain replacement, in hindsight i should’ve have removed the cam when i had all the timing gear out, but i guess that’s the fun of learning!. cheers Chris.

Some excerpts from Guzziology below about camshaft specifications, if any help. Generally sounds like B10 is quite good to me…

Guzziology snip 1.JPG
Guzziology snip 2.JPG
Guzziology snip 3.JPG

This is what i used to check my valve lift and found that one cam lobe was 0.2mm down on the rest, i have now removed the cam and it needs replacing, so yet more expenditure! The wear on the cam shows how important regular oil changes are , which it will get from now on.
Also any advice on where the best place would be to buy a new cam would be very helpful, i will give motomecca and gutsibits a ring on Monday and see what they have to offer. Thanks Chris

Hi Chris it does seem you have hit some bad luck on your engine rebuild, from a simple mix up on your first set of piston rings to where you find yourself now. If you can live with the endless expenditure I am certain what you end up with will be long lived and great fun so worth your endeavour!
Keep us all posted on the rebuild!

BTW - I took the easy way out and took mine to Baldrick. I got lucky with just new followers, cam chain and tensioner and it really is as good as new

The total joke of it all is when i bought the bike 2 years ago the previous owner had just spent £1500 on the engine and gearbox at a moto guzzi dealership (Bikersworld in east grinstead ) (I have all the receipts for the work), all i can say is I’m glad not reliant on so called specialists, as i have now spent approx 2k on the engine putting it right! And 2 years on and off rebuilding the bike, But i don’t mind too much as I’m not going to sell it, it will last for years and is a cracking looking bike, (as long as i don’t throw it down the road that is!)

I’d be interested how a new camshaft’s lobes measure.

All the same i would hope!
The lift on the cam i have removed measured right cylinder exhaust at 7.08mm, inlet 7.00mm, left cylinder exhaust 6.88mm and inlet at 7.00mm.
When i measured the cam lobes, all were all approx 32mm bar the left exhaust lobe at 31.80mm

All I’m suggesting is Moto Guzzi engineering tolerances may not be quite the same as Honda’s.

Only pulling ya leg!, ill let you know when i get it.
Off the subject slightly, i have tried to post pictures from my i pad and i phone on to this site and for some reason it wont let me, does this site support mobile devices? Cheers Chris.

I can never find a link for it on my iPhone. So I can’t either.

PS: (edit) There is a mobile view, I get it on the iPhone, and it’s completely different to the PC view. Some other links are missing too.

I enable desktop view on me fone but can only post pics by attachments…which have to be low res…good free app does this mind you…

Ah that’s how you do it! Did wonder


I have been in touch with gutsibits and even though they list many cams they only can provide the p3 cam, i cant seem to get a B10 cam from anywhere (I have been on the internet and phone to the whole of Europe!), motomecca offer to regrind my cam to B10 specification but I’m a little concerned whether their process is any good. ide rather go for a new cam if possible and i don’t really want to go a higher lift than the B10 cam due to the potential can of worms of changing valve springs, valve spring retainers, different push rods needed, timing to be altered from standard and putting more stress on the valves themselves.
Im not trying to build a race bike, just making some sensible mods while the parts need replacing, and the fact i have already changed all of the above parts mentioned with genuine moto guzzi parts so i wont be changing them again, unless i win the lotto of coarse!

for what it’s worth the run of the mill cooking cam, (1405 3301 on the list) is not that much different to the B10, (seat of the pants dyno, easy breathing+rejetted cali 111 v modified 1000s of the big valve variety).
Cash spent on suspension and quality brakes may be cash well spent :smiley: .
Belated Happy New Year to one and all,

Cam situation now sorted, i contacted Tony at kent cams and as soon as i said i wanted a cam for a Moto guzzi 850 le mans he said they used to do all of the cam work for Raceco and still have all the profile specifications stored, he also knew all the cam variations for my bike off the top of his head!, so i will get them to regrind my original cam to B10 spec, and it is only £130 all in!