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my 912 ul has started to run rough at cruise speeds, starts well, idles well, accelerates well, climbs well, after storing it for 5 months and when i checked the plugs which are only 18 hours old the plugs in cylinder three the porcelain is still white while the rest are a normal brown colour,
anyone have this experience or ideas
tony
How many hours out of storage? Did you change the fuel filter and gas after storage? How about looking at the carb bowls & clean them out too. How are the EGTs, the clip frequently needs adjusting in the cool temps. Also winter gas blends may affect it. I had similar problems before and was advised to get some fresh gas. After protesting that my gas was still good, I listened and got fresh gas AND a good running engine again!
larry
Does your gearbox have an overload clutch?
If you do not have an overload clutch and it has started running rough at cruise or in mild decent and your carbs are in sync then you need a gearbox rebuild.
Installing the overload clutch will fix this issue. All newer 912 gearboxes come with the clutch for this reason.
Also, do an oil analysis and look for high iron.
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i bought a carbmate to try and synchronize the carbs and make it smoother but no go, so took them off and cleaned them, the one carb on the side with real clean plugs was dirty for sure and the other a little. reinstalled the carbs, set the idle at 1800, synchronized with the carbmate and now she is smooth.
i will check the new plugs in 15 to 20 hours and see if they have the same problem but for now she is running very smooth, i am thinking maybe smoother than before
the smooth running lasted about 10 minutes now back to rough running at cruise 4300 to 5300 rpm, i have lowered the main jets one notch and will try that, any one else got any more ideas, sort of running out of things to do and check
What are your EGTs running at cruise?
i do not run any egt's, only the oil and water temp gauges, everything there is the same. fun and games as long as every one is safe
Did you not read my post? Do you have an overload clutch?If not chances are your gearbox is at issue from the long storage. I do not post in jest.Quote:
Originally Posted by tiketyboo
gear box is fine and the rough running is intermittent not steady like a gear box or prop problem and we fixed it once with a carb clean for about 10 minutes