Gregory Bender

Engine out? Check these things

Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models


// //

If you've gone to all the trouble to remove the engine from your bike, you might as well check and replace as necessary the following items (it sure beats taking the engine out again).

Top of the engine

Timing chest

Inside the bell housing

Thanks to Charley Cole of Zydeco Racing who posted this information on the Yahoo! Loopframe_Guzzi news group. In Charley's own words:

There is another major source of oil which can get into the bell housing and wreck your clutch that no one ever seems to mention. It's the two holes in the top of the crankcase for the breather tube and oil return line. Any oil that gets on top of the motor from a variety of sources can leak down those holes because no grommet or seal is used there and the metal tubes are much smaller than the holes they go through. Also, the short connecting rubber hoses fit over the fittings on the engine breather and the tubing going into the bell housing, so any deterioration of the hoses or loosening of the hose clamps allows a leak there. The tubes are then a direct path for the oil to run into the bell housing.

Whenever I have the motor and gearbox separated I always completely degrease the housing and tubes, and then seal that area on the inside where the holes in the crankcase are. You should take the opportunity to bend the tubing so that it is not in contact with the crankcase. The breather is mild steel and the oil return line is cad or zinc plated copper, so both are quite soft and can wear through from vibration. Also, while you are in there, check the routing of the smaller diameter oil drain line and make sure it is not in contact with the crankcase as it makes it's 180 degree semicircular journey from the top to the bottom of the bell housing. I put 3 or 4 dabs of silicone on the back of the crankcase that join the crankcase and the tubing. This damps any vibration and prevents the tubing from ever coming to rest on the crankcase. I've seen a number of these that were nearly worn through from vibration. If that ever happened you would destroy your clutch within miles and be pouring oil on your rear tire.

Be sure to check or replace the crush washers on the oil return banjo fitting. Another caution, that probably doesn't affect many Loop frame motors, regards the fitting of crankcase or oil pan spacers. Most are not very tall (around a half inch thick) but the ones I have used are around and inch thick. If you use one of these make sure that your oil return banjo fitting still protrudes below the level of the oil in your pan. If not you will have equalized the air pressure in your breather coming from the breather and oil return line and your check ball will not lift off it's seat and allow the engine to breath. You can also prevent oil from draining effectively from the breather causing it to wet sump and cease to function. If the breather completely loads up, you will start pushing oil out your vent hose like you popped a ring.