Need Engine Advice

[mikewilson30]

I have a 1965 CL 72 and it's on the road and about 95% restored. I had a new one in 1965 so it is nice having one again. But I have a few details to resolve:<br />1. There are two nipples that are screwed into the back on the Head assembly. These had hoses that were connected to the right air cleaner. The shop manual calls them air vent tubes. Mine are plugged up. I can't blow air through them. I don't know where they end up inside the engine. My bike also backfires a bit on decelleration. It might be connected.<br />Any one know the purpose of these vents? Do they end up in the crankcase space or possibly in the intake port area? <br /><br />2. When fuel is low it starts to miss and I switch to &quot;reserve&quot;. It does not help. I need to shosh the fuel around to the right hand side of the tank and can then make to a gas station. <br />The Petcock on mine has a tube that stick up about 2.5 or 3 inches in the tank so when the fuel reaches the top of the tube, it shuts down. The cross connect tube is there and flows fine.<br />Do I have the correct petcock installed? How is it supposed to work? <br />Thanks,<br />Mike

[georGe]

1) the vents lead into the the valve guides as a vent you wont be able to pass air w/ an air hose as the port is small.They are there to help keep oil from running down the valve stem into the cylinder,they basically work off of vaccum from the air cleaner<br />2) Problem could be any number of things but not caused by the above . Id start buy making sure the tank cap is not over tightened causing air lock in the tank. I would also make sure that the reserve circuit in the fuel cock is able to flow. These are just basic answers ta get ya started if by doing the above nothing changes post back and Ill give ya my address to send me money for the answer....joke !<br />3) click on the marketplace link at the left of the page and consider buying the manuals.You can not believe how much info is in there.<br /><br />Good Luck<br />georGe

[mikewilson30]

Wow! I finally found a place where people actually know something!<br /><br />You may have helped me with another problem. Seems I do have a bit of an oil problem. It hangs around the flanges that hold in the exhaust pipes. The engine does not smoke and has new rings so I do believe it is a valve guide problem. <br /><br />When I had the head taken apart and the valves out, I still could not get ANY air through the air vents. I think they are plugged.<br /><br />If they need a small vacuum to work properly, then I will need to install the air tube into the air cleaners. My new air cleaners do not have the welded on tubes like the orginal ones did.<br /><br />OK on the hint of the books. I have a shop manual but there are a lot of gaps in it.<br /><br />Thanks again,<br />Mike