I am restoring a Le Mans 1000 Mk4 and just need to check with those familiar with the engine.
the valve guides are very worn and so I am renewing the guides. I have machined my own guide removal tools drifts and am ready to heat the head.
The guide looks to have a snap ring fitted about 2cm from the top end which I assume is to stop the guide being inserted too far into the head.
Before I start beating seven bells out of the guide could anyone please confirm that the guide can be safely removed without having to get the snap ring out first.
Its probably a daft question but it would save a lot of grief to get confirmation before bitterly regretting I did not ask - as it is the first time working on a Guzzi.
Many thanks
best arm yourself with a copy of guzziology
the bible/Koran/Talmud of Guzzi maintenance
Because of the limited room for error on the “big valve” heads I ended up using a specialst firm.
Seasoned engineerswere reluctant.
I’ll ask about the circlipd when I see a few of them when we meet tomorrow.
Good luck
Steve
Same here on using a specialist, on mine the exhaust valve seats were also receding, (always use the high octane when I can) so it got new guides, new exhaust valves and hardened seats, reused the inlet valves and all the valve springs , motor is a lot quieter and seems to pull better, (though that could be just in my head).
The bike had done less than 30000 miles, all Good nowđź‘Ť
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Thanks for the comments . The engineering is easy enough- I have fitted many valve guides in the past but they were usually flanged so impossible to fit in the wrong position. Reaming the guide and re-cutting the seat is straightforward - as is removing old seats and fitting new - if necessary.
I am now sure the guides will come out by heating the head in the oven and using a drift to punch them out.
The bike has done 42000 miles but the
wear on the valve guides is quite severe compared to Japanese four strokes with similar mileage. Looks that valve height, rocker tip condition and rocker bush clearance are critical. I suppose the acute valve angle exacerbates wear rate of guides on this engine.
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Don’t heat the head to remove if they’re Bronze guides , bronze has a HIGHER coefficient rate of expansion than aluminium , if the new guides are bronze put them in the freezer for an hour before heating the head to fit ,
Derek
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Many thanks .
Guides are out, bores are good, new
guides are in the freezer. Guides are 3mm longer than the originals. The lemans 1000 manual supplement gives length of the guide as 49mm whereas new guides are 52mm so have machined these to suit the required
Recommended length.
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