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California valve adjustment

zjohnston

Just got it firing!
Joined
Jul 27, 2012
Messages
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Location
Knotts Island, NC
I almost refrain from writing this because I know how motorcycle guys are, especially niche motorcycle guys. Despite the raised eyebrows this will probably bring maybe someone will relate. I have been around bikes all my life and have vast mechanical experience with a variety of machines but this is my first Moto Guzzi. I just finished restoring a 90 california III and noticed after the engine was at temperature the valve noise was a little more than I liked. I had adjusted the valves to spec. but figured I should recheck it. The clearance was still good, so I checked the difference in the clearance from cold to hot to see if I would be able to close it up a little. What I found was when hot the valve clearance for both valves increased 4-5 thou. from the cold setting. .006 cold to .011 hot intake and .008cold to .013 hot for the exhaust. This is backwards from what I thought would happen but I attribute it to the aluminum cylinders growing in length moving the heads away from the cam more than the pushrods and valve stems grow. In short I set the valve clearance at .002 cold for both valves, now I have 6-7 when hot and a quiet valve train. I guess it's really no different than Harley sportsters and shovel heads, valve clearance is right when you can still just spin the pushrods with your fingers.
 
I can't say I agree with what you did. A Guzzi should have more clearance than 0.002 for both intake and exhaust. I'd recommend the newer specification for the 1100 engines on your 1000 motor of 0.004 intake, and 0.006 exhaust. The US specification for valves was 0.002 and 0.004 to reduce noise, but problems were encountered. The 0.004 and 0.006 world specification does seem to work best.
 
My '85 SP 11 V1000 "Cafe Roar Hoar" is quite "ticky" when she's cold . When she's hot I dont hear it .I just hear her music from the pipes . The odd tiny little drip of oil sometimes on the floor of the garage where I park her , just like any pedigree dog , she leaves the odd mark here and there .
Theres one thing I'd be very cautious about , that is running tight tappets with an air cooled engine. I did it once with an old Norton 500 twin , only to burn an exhaust valve soon afterwards .( cast iron barrel and head, with duralium pushrods).
One thing is for sure , if you stick to the original specification requirement , you wont go wrong !
In the big picture whats a bit of a tick anyway . My ears and hearing is that poked it sounds like 5million locusts most of the time anyway .mmmmmmmm, I know what you're thinkin .
Regards Supaflee
 
My Grand-Pa always said: "I'd rather hear 'em than smell 'em".

LOL > Let 'em rattle a bit & get used to it or pull the mufflers off & wear a full face brain bucket with cotton stuck in your ears. < LOL
 
What I found was when hot the valve clearance for both valves increased 4-5 thou. from the cold setting.

<scratching head> Never have heard of such a thing on Guzzis.. but then, I've never checked it either.
 
zjohnston said:
I almost refrain from writing this because I know how motorcycle guys are, especially niche motorcycle guys. .

Very interesting! I'm glad you did post it.

This is, as you have indicated, contrary to the norm. All of mine get quieter as they reach operating temp.

I would just like to confirm 2 things. Sorry but I need to ask as I am one of those niche motorcycle guys. :lol:

1. That you adjusted the valves at TDC on the compression stroke on a cold engine. I always remove the rocker covers and watch the valves as I rotate the engine and feel for TDC through the plug port. Double checked with the timing mark.
2. You have checked and re-torqued the head bolts.

This is a puzzle that I would like to understand. The outer engine case is open to the air so should be at a lower temperature than the internals that can only disspiate heat via the oil and breather system. Logically the push rods, etc should expand more.

Just a few thoughts.

Heads need re-torquing?
Different gasket material than the normal composite?
Some aftermarket pushrods?
Valve seat expansion? I've never heard of it either but I'm grasping at straws! :lol:
Camshaft bearing allowing movement?
Worn rocker spindle bushes?

Please let us know if you discover anything.

Cheers and thanks for letting us know.

Rod
 
As I recall, the only change in guzzi valve clearance was when they switched from iron to aluminum rocker holders. The coefficient of expansion allowed the aluminum variety to be a bit tighter. I have always worried if I could not hear my valves. Is your exhaust to quiet ;) There are other reasons you get valve clatter when properly set, but Roper, C from I, or somebody else will have to chime in
 
I haven't considered the head bolt torque. Everything on the bike is stock though, nothing has been done to the engine except normal maintenance. My father in law owned it since new and I got it from him a while back. I did check the clearance cold and rechecked hot, and while the engine cooled back down I periodically checked the clearance and it slowly got tighter. Anyway I have been running at .002 for a few thousand miles now and no problems or valve noise. I think I might check the head bolt torque though.
 
Hello all, resurrecting this thread 7+ years later since last post. So, I am about to go on a long trip and some preventive maintenance is in order. One of the things I want to do is check valve clearance, especially since when hot my 2001 California Special makes a tapping noise more from the right cylinder. My method is removing covers and spark plug, remove the rubber plug for visual confirmation of TDC, put bike in high gear and slowly rotate the wheel while also feeling the piston coming up (I often use a chopstick). Once at the right spot, feel both rockers for free play and adjust as needed. Am I correct? Also just for confirmation, what are the clearances for my model? Thank you!
 
Clearance should be set cold. My preference for engine rotation is to remove the alternator cover and rotate the engine with a socket or wrench. Intake is 0.004 inch, and exhaust is 0.006 inch. I leave the rubber bung in place and feel for TDC with with both valves closed using an instrument similar to your chop stick.
 
Hey John thanks for the feedback. Since this is my first ever California can you tell me if I absolutely need new gaskets for the valve covers or the existing one is reusable (provided it was removed carefully). Thanks!
 
Hey John thanks for the feedback. Since this is my first ever California can you tell me if I absolutely need new gaskets for the valve covers or the existing one is reusable (provided it was removed carefully). Thanks!

New gasket not needed if no damage to the existing. Sometimes the gasket will stick to one side, if it does don't try to remove if it stays intact. If it doesn't tear could be re-usable. Sometime I will use a bit of anaerobic sealant around the bottom half of the area to help it seal if the gasket is questionable. I would have new ones on hand. The extra thick ones from MG cycle give good service.
 
That's what I thought. MG cycle is about 2 hours (and a nice ride) away from where I live. Good to know about their extra thick gaskets; will probably pay them a visit soon, thanks again John!
 
Noise valves are happy valves, you may get some extra performance but it is not worth the potential damge you may do to the engine by making them too tight.
 
Agreed! A larger gap adjustment is better than a tight one. My understanding is when valves are adjusted to the recommended specification should not be "noisy", just ...happily audible. Mine sounds fine when cold but it becomes noisier when it warms up. Shouldn't it be the other way around? Plus that only happens on the right site. The left remains relatively quiet when both cold and hot. Also, I checked the valve cover temperature with a laser thermometer and after a short ride the right head runs a little hotter by about 10 F degrees. Any ideas? Thank you!
 
Last edited:
Maybe my slideshow video is useful for this thread.
You can find some additional info in the text below the video.

 
Nice slide show, but instead of small vice grips, I use a small adjustable wrench. Took kits of early bikes had a small bar with a slot that was used during valve adjustments.
 
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