Black carbon specks from 914 exhaust P2008

[Mike B]

Cleaning up the ship after a recent flight I noticed black carbon specks scattered from the exhaust under the belly and even the left landing gear leg and wheel pant.  I've had some of this in the past but not nearly to this extent.  I did have some ground delay for takeoff in the neighborhood of 15 minutes or so.  I'm running mogas exclusively.  I've noticed black carbon in the exhaust pipe of other 914's and those like mine are always black, unlike my previous Continental and Lycomings where the exhaust is light tan and dry.  To me this would indicate an overly rich mixture.  The engine runs great, no stumbles, good mag checks and although I haven't run at full turbo power in the detent until the warning light recently I do keep full detent power to 2 or 3 thousand feet.  I'm wondering if this could be related to the carb floats as I have not yet checked them per the bulletin.  Can anyone chime in on this?

[buzz]

I have never seen this on my 914. My experience and some others as well who have had stuck or heavy floats have had rough running engine, high fuel flow, flooded engine at start, and fuel showing from the vent tube. My float issue started with a few drops from the vent which I mistakenly thought was normal. Sometime after that I could not start due to flooded engine and had a large stream of fuel dumping on the ground. I had stuck floats on one side due to gunk on the vertical pin the floats ride on.

[Mike B]

Thanks for the reply, Buzz....
Went to the hangar to do a run up and check for the oil specks after having cleaned them up from the last flight.  I would have to say the specks started about two or 3 flying hours ago and appear oily.  After a warm up and 4000 rpm mag check I did the cool down and found quite a few per the pictures.  Giving this some further thought I think they it may be coming from the turbo seal.  The oil loss is negligible.  TT on the engine is about 85 hours since new.  Still looking for opinions or other inputs....

mb

[Ed Midgley]

Can you smear them or are they hard?
Ed

[Mike B]

Morning, Ed....
The specks are semi dry. I rubbed them and it would appear to be more carbon than oil but it's hard to be sure. My question is what caused this to come about. it's been about 10 hours since my last oil change, with 85 hours total time on the engine this is the first time I've seen this, the oil is clean and the level hasn't changed and the engine seems to be running fine at all rpm ranges.

mb

[MarkGregor]

Clean them off and see if they return. If they do I suggest contacting Dean at Lockwood or Brett at Leading edge for their opinion.

[cole505]

Jan 9, 2021 17:12:45 GMT Mike B said:

Cleaning up the ship after a recent flight I noticed black carbon specks scattered from the exhaust under the belly and even the left landing gear leg and wheel pant.  I've had some of this in the past but not nearly to this extent.  I did have some ground delay for takeoff in the neighborhood of 15 minutes or so.  I'm running mogas exclusively.  I've noticed black carbon in the exhaust pipe of other 914's and those like mine are always black, unlike my previous Continental and Lycomings where the exhaust is light tan and dry.  To me this would indicate an overly rich mixture.  The engine runs great, no stumbles, good mag checks and although I haven't run at full turbo power in the detent until the warning light recently I do keep full detent power to 2 or 3 thousand feet.  I'm wondering if this could be related to the carb floats as I have not yet checked them per the bulletin.  Can anyone chime in on this?

Hi Mike B,

I have the same black specks you speak about........ And I have changed the floats on my P-2008, They seem to be fading as I get more time on the engine...... I purchased my P-2008 new with 30 hours they were there then also ..... I also run Mobil 4T pure synthetic racing oil ( 95 percent of the time Mo Gas ) to help the Turbo deal with the high operating temps........ And I do run the Turbo the full 5 mins after take off to ensure all moisture is dissipated...... little or no oil usage. Let me know how your research go’s. I will keep you informed also as I accumulate more hours.

Been grounded due to an improper ADSB install. I am At Ryan Field 1-13-2021 in Tucson AZ. My avionics guy is pulling his hair out trying to figure out what the guys did on the initial install ( I waited a full year for him to get a look at it ) And with a warning ⚠️ From the FAA that my ADSB was non complaint since it was put into service....... I had to request a special waver to be able to fly the three hours into controlled airspace to get to Ryan from Boulder City KBVU all under class B airspace ..... And to address a loud radio squeal that has Haunted me since the day I left Mankato ........ praying to have it all repaired. It would be so nice to have a squawk free Airplane..... God willing and the river don’t rise..... ( John Wayne ) 😁

I never had them on the 912 like you said brown to tan always on the exhaust pipe...... so it must be Turbo related.......

Ray & Lucy ✈️👍🏻☀️🇺🇸✅ 

[Mike B]

Ray & Lucy....
Thanks for the reply. Happy to know I'm not alone out here with this exhaust issue. I'm meeting with a Rotax specialist from Wisconsin next week when he will be in Tampa on another Tecnam project. We'll be checking the carb floats, changing to full synthetic oil and also checking he needle valve settings to insure the engine is not set too rich. In my case, having bought new (40 hrs.) like you, I had no specks at all until recently. Other than a fuel leak on the firewall mounted electric boost pump assembly I have had no other squawks on the ship. I'll do a post on the results of our inspection next week.

ps...I've been into Ryan field a couple of times with my Bonanza when we were Calif. Snowbirds. The Pima Air Museum was OUTSTANDING.

mb

[cole505]

Jan 14, 2021 14:37:39 GMT Mike B said:

Ray & Lucy....
Thanks for the reply. Happy to know I'm not alone out here with this exhaust issue. I'm meeting with a Rotax specialist from Wisconsin next week when he will be in Tampa on another Tecnam project. We'll be checking the carb floats, changing to full synthetic oil and also checking he needle valve settings to insure the engine is not set too rich. In my case, having bought new (40 hrs.) like you, I had no specks at all until recently. Other than a fuel leak on the firewall mounted electric boost pump assembly I have had no other squawks on the ship. I'll do a post on the results of our inspection next week.

ps...I've been into Ryan field a couple of times with my Bonanza when we were Calif. Snowbirds. The Pima Air Museum was OUTSTANDING.

mb

Hi Mike,

‘’That’s awesome! Glad you have been to Ryan Airfield......... I just got back from RYAN and can you believe tan to brown INSIDE the exhaust pipe.......... I did the five min. Turbo run and a full three and a half hour non stop flt from Ryan to Boulder City KBVU ....... 35knt head wind >... kept her wound up to 5500 all the way perfect flt all temps in range....... and no black carbon inside side the exhaust pipe...... but a few black specks on the landing gear...... getting better all the time....👍🏻

Ray & Lucy 👍🏻✅✅✈️🇺🇸

[Mike B]

Jan 13, 2021 15:37:07 GMT cole505 said:

Jan 9, 2021 17:12:45 GMT Mike B said:

Cleaning up the ship after a recent flight I noticed black carbon specks scattered from the exhaust under the belly and even the left landing gear leg and wheel pant.  I've had some of this in the past but not nearly to this extent.  I did have some ground delay for takeoff in the neighborhood of 15 minutes or so.  I'm running mogas exclusively.  I've noticed black carbon in the exhaust pipe of other 914's and those like mine are always black, unlike my previous Continental and Lycomings where the exhaust is light tan and dry.  To me this would indicate an overly rich mixture.  The engine runs great, no stumbles, good mag checks and although I haven't run at full turbo power in the detent until the warning light recently I do keep full detent power to 2 or 3 thousand feet.  I'm wondering if this could be related to the carb floats as I have not yet checked them per the bulletin.  Can anyone chime in on this?

Hi Mike B,

I have the same black specks you speak about........ And I have changed the floats on my P-2008, They seem to be fading as I get more time on the engine...... I purchased my P-2008 new with 30 hours they were there then also ..... I also run Mobil 4T pure synthetic racing oil ( 95 percent of the time Mo Gas ) to help the Turbo deal with the high operating temps........ And I do run the Turbo the full 5 mins after take off to ensure all moisture is dissipated...... little or no oil usage. Let me know how your research go’s. I will keep you informed also as I accumulate more hours.

Been grounded due to an improper ADSB install. I am At Ryan Field 1-13-2021 in Tucson AZ. My avionics guy is pulling his hair out trying to figure out what the guys did on the initial install ( I waited a full year for him to get a look at it ) And with a warning ⚠️ From the FAA that my ADSB was non complaint since it was put into service....... I had to request a special waver to be able to fly the three hours into controlled airspace to get to Ryan from Boulder City KBVU all under class B airspace ..... And to address a loud radio squeal that has Haunted me since the day I left Mankato ........ praying to have it all repaired. It would be so nice to have a squawk free Airplane..... God willing and the river don’t rise..... ( John Wayne ) 😁

I never had them on the 912 like you said brown to tan always on the exhaust pipe...... so it must be Turbo related.......

Ray & Lucy ✈️👍🏻☀️🇺🇸✅ 

[Mike B]

Hello again Ray & Lucy...

Met with a traveling Rotax specialist at Tampa Exec. airport yesterday. He removed the carb bowls and found the Bing floats installed. He removed them and installed the new Rotax floats. He was going to weigh the Bings last night and report back regarding any absorbed gas. He also found the mixture screws on each carb set to a richer than recommended setting (more than 1 1/2 turns out) so they were reset to a leaner setting. We then changed from Sport 4 to full synthetic Amzoil. An interesting observation was that the day before yesterday I flew for almost an hour allowing 5 minutes at full turbo power in the climb, landed at Arcadia, FL for Taco Tuesday and returned to Sarasota. There were noticeably fewer carbon specs that in previous flights, then on the flight home from Tampa Exec. there were even fewer specks. I'll be doing some flying through the weekend and will let you know the changes, if any.

Sorry to hear about your avionics issues. Everything A-OK with mine. Dual G3X screens, GTR200 Com., GMA240 Audio Panel, GMC 307 Auto Pilot.

Mike

[cole505]

Hi Mike,

Sounds good! Glad you got the Floats changed out.......l would be interested to know what the correct mixture settings are on the 914 carbs and how they decide the amount of turns to have the right fuel air mix?

Glad all your Avionics are good 👍🏻 Make to to due An ADSB flight in controlled airspace to confirm that your ADSB is talking to the GPS GROUND stations. It was a real shock and eye opener getting a call from the FAA informing me that From day one that my airplane was put into service the ADSB was not Compliant...... Still waiting on Walter Decosta Tecanm Italy to make a decision on the reimbursement for the $2000.00 I paid to correct a factory Mistake by Shannon. He failed to insure the required Quality control checks were done before allowing N356X to fly. It flew from Sebring to Mankato ADSB Non-compliant And I spent the last year in total violation flying in controlled air space with a non operational ADSB SYSTEM on my airplane. Just Hope Tecanam does the right thing we the customer are usually wrong. Trying to be optimistically hopeful, but a perfect example of Tecnam Not doing the right thing was the oil return line the factory strapped directly to the exhaust manifold was ( and burned through lost most of the oil in the tank ) my fault and they turned they’re back stating it was my fault! That one cost me another $2000.00 thank goodness for a factory warranty. I am still trying to figure out what exactly does the word warranty mean? I think the Translation from Italian to English is different and means nothing? One of the reasons to buy a new airplane is the peace of mind that if there is a problem they will make it right........ I think you get the point and I am glad your able to get the right assistance and hope Tecanam takes good care of you ✅✈️👍🏻🇺🇸 Please keep me posted and I will do the same...... Be safe be well and enjoy your New airplane ✈️ ✅👍🏻👍🏻👍🏻✈️🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸

Ray & Lucy

Look forward to reading your follow up on the back specks........ I am sure that as you get more time on your engine it will disappear. I am wondering if anyone else on the Tecnam talk? I have heard no mention of it?

[cole505]

Jan 21, 2021 18:45:32 GMT Mike B said:

Hello again Ray & Lucy...

Met with a traveling Rotax specialist at Tampa Exec. airport yesterday. He removed the carb bowls and found the Bing floats installed. He removed them and installed the new Rotax floats. He was going to weigh the Bings last night and report back regarding any absorbed gas. He also found the mixture screws on each carb set to a richer than recommended setting (more than 1 1/2 turns out) so they were reset to a leaner setting. We then changed from Sport 4 to full synthetic Amzoil. An interesting observation was that the day before yesterday I flew for almost an hour allowing 5 minutes at full turbo power in the climb, landed at Arcadia, FL for Taco Tuesday and returned to Sarasota. There were noticeably fewer carbon specs that in previous flights, then on the flight home from Tampa Exec. there were even fewer specks. I'll be doing some flying through the weekend and will let you know the changes, if any.

Sorry to hear about your avionics issues. Everything A-OK with mine. Dual G3X screens, GTR200 Com., GMA240 Audio Panel, GMC 307 Auto Pilot.

Mike

Hi Mike,

I was wondering what the Tech Guys found out? On your carbon issues ? Hope all is well, looking forward to hearing from you ✅✈️😊🇺🇸👍🏻

Ray & Lucy✅✈️😊😊🇺🇸🇺🇸👍🏻✈️✅