I just started my new 912 for the first time and heard what I presume to be a little valve tappet noise and slightly rough idle on both ignitions. After shutdown I checked the tappets and found several that appear to not be primed yet. I am wondering how many others have encountered this. My first 12's 912 ran flawlessly out of the box with only a carb synch.
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912 Tappet Noise?
- Thread starter Dave12
- Start date
Yes, saw pressures of #50 0r better. Also. prior to start-up, I ran the starter with ign. off until I had good pressure. Upon start-up, the oil pressure immediately shot to the top of the green arc.
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I think Jesse ment the prescribed purge procedure where you use an air pressure line to help pressurize the oil system, while turning the engine ov we by hand.
Understood, the procedure went well. Maybe I should try it again? What do you guys think? I fail to see it hurting anything. My thought is the loose valve lash, was causing the slightly rough run. I can't find a leaking vac source. Weather is so miserable, I can't try anything now.
I called my friend and he does two purges on a brand new engine. It leaves nothing to chance and never has soft lifters. If they were soft he said to do another oil purge. Won't hurt a thing and it will most likely solve your problem. Before the first engine start there should not be any soft lifters. That means there is air still in the system.
Dave, what do the wings have to do with an engine run?
Just to avoid a mishap as others have experienced (not with RV12's). Has any of you other guys ran the engine without wings? I just have not wanted to take the risk, but have thought about it many times?
Gagarin737
Well Known Member
No problem running the engine without the wings on.
YouTube: first engine start
More fun with smoke on ;-)
YouTube: first engine start
More fun with smoke on ;-)
Same here!
Thanks guys. BTW John, The West System epoxy worked very well on that fairing we were talking about. I have tried the more generic epoxies and hardners on ABS in the past without alot of success. Good tip.
The noisy lifter problem seems to be under control. The rough running is still a problem. I have raw fuel in the drip try on the pilot's side after a 5 minute run and this side is 150 degrees cooler on the egt. Looks like bad floats right out of the box. Looks like I am buying a digital scale.
A float problem is just one of a number of things that could cause it.
Could also be contamination.
You didn't mention putting gauges on and doing a carb. synch yet. If the carb synch is out by quite a bit, it can make it run quite rough and cause a loss of fuel. It would also cause an EGT imbalance.
Throttle arms are on the stops and idle is 2300 rpm. I was originally thinking a bad vacuum leak until I saw raw fuel dripping off the bottom of the pilot's side bing. I don't see anyway to synch until I get the idle down. I will be weighing the floats shortly with a new scale in hand. I am very interested to see the bowls.
Hi Dave,
Are your idle stop screws all the way out so the throttle stop doesn't engage? If they are and you still have travel on the throttle arm back towards idle then you need to shorten the throttle cable on the throttle arm. Do a mechanical sync after this and you should be right in the ballpark for idle.
Are your idle stop screws all the way out so the throttle stop doesn't engage? If they are and you still have travel on the throttle arm back towards idle then you need to shorten the throttle cable on the throttle arm. Do a mechanical sync after this and you should be right in the ballpark for idle.
RFSchaller
Well Known Member
Dave,
I drove my RV-12 in car mode on the taxiways for about an hour. No issue with the wings off!
Just remember you need the "Spar Override" button to start the engine.
Rich
I drove my RV-12 in car mode on the taxiways for about an hour. No issue with the wings off!
Just remember you need the "Spar Override" button to start the engine.
Rich
