Hi, My Imola II is running but the rocker s are slightly offset from the valves and cause them to wear on one side, does anyone know why this is? as this engine has lots of issues with the 4 valve head does that mean that parts from the V65 4 valve may have been fitted in the past which may be slightly wider or was there a change thro the production run? any info on this greatly appreciated - lastly
can it be converted to 2 Valve? if so has anyone got any heads for sale?
Mark
Do you have a photo, it might help. I have lots of V65 Lario bits so could compare sizes etc if you provided measurements, although my guess wld be the rocker gear would be the same on both.
2 and 4 valve frames are similar enough to swap engines I have been told so you could probably put a 2 valve engine in, preferably with a matched gearbox. Anything else would, I think, be technically challenging
Cheers
I should add that they all do that. Due to design the rockers hit the valves off centre. I have heard it said this can mushroom the valves over time. Guzzi made lash caps to protect the ends as a retro mod and Guzzi Pui in Germany can supply them new.
The biggest problem with the valvegear in most people’s opinion is that the valve springs are much too strong and this can damage the cam lobes, shear them or snap valves. There are solutions centred around replacing the OEM springs with lighter ones. Suzuki GN250 one choice. Lario Brian on FB has a document that lists mods and part numbers for his fix he will send you or I can if you PM me.
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I think sometimes that the off centre rocker/valve thing is a design feature meant to rotate the valve during use and so distribute the wear. Certainly in some other makes.
Funny, a similar thread came up on Facebook just the other day . Maybe this will help you
https://www.facebook.com/photo.php?fbid=1443888505723975&set=gm.1752336031465540&type=3&theater
I think you’re right Tony,good point and I did read that somewhere I’m sure - that would mean I suppose the problem is the soft metal of the valve mushrooming?
Cheers
No way can I see the offset in the above photo turning the valve stem around. Made impossible by the pressure of the springs at least I would think.