carbon deposits on piston crowns 912uls

by john mans in General Tech Discussion 9 years ago

Good day everybody! While doing my annual inspection I noticed oil fowling on #1 spark plugs. Peering through the plug hole I see lots of carbon on the piston dome.The rest of the cylinders have some carbon, but not much.The other plugs are not fowled. Compression is still good, and the engine is running good. I'm running premium auto gas, and aero shell sport oil. 360 hrs. On 2009 engine. I operate in a cool climate, summer only. Thanks for all replys! 103

Re: carbon deposits on piston crowns 912uls

by Roger Lee » 9 years ago

Roger Lee

131 5.38k 5.44k

Hi John,

Carbon build up usually comes from too much idling and or too wide a plug gap. Make sure the plugs are gapped between .023 - .027.
The wider gap is better for hot weather and the narrow gap for cold winter weather. Also flying at too low an rpm all the time. Better to be around 5100 - 5400 during cruise and not down in the 4000's.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Report
Re: carbon deposits on piston crowns 912uls

by Kevin Kane » 9 years ago

Kevin Kane

1 32 24

John,

Is the engine consuming oil? You may have a bad valve seal.

Report
Re: carbon deposits on piston crowns 912uls

by Capt. Siva, » 5 years ago

Capt. Siva,

25 266 738

What is best way to remove such carbon deposit on piston?

Is there any spray?

Report

You do not have permissions to reply to this topic.

Title	Category	Replies
EGT Monitoring on 912ULS--Why only 2 of 4 cylinders?	912 / 914 Technical Questions	11
912ULS carb overflowing	912 / 914 Technical Questions	20
Rotax 912ULS Main Bearings	912 / 914 Technical Questions	1
912ULS in a Tecnam Bravo	912 / 914 Technical Questions	4
Rotax 912ULS	Engines	0