Cessna 150 vibration problem

I just wanted to give a quick update on my vibration problem. I also wanted to say thanks to Tom D. I ended up purchasing the used carb in the pictures and replaced the New carb that was installed just before my problem began. The new carb being a one piece Venturi and the used one being a two piece. Swapping the new for the old one fixed my problem. Thanks again to Tom D and the others here that helped point me in the right direction.
 
My $0.02. #1 The one piece venturi does NOT work well with the old style discharge nozzle.
#2 When you get a new or rebuilt carb, you MUST ensure the entire induction system is tight or you WILL be chasing your tail.

Got a rebuilt carburetor from Avstar last year, replaced all the intake manifold gaskets & tube rubbers and sealed the leaking sump pipes (lycoming sump) and couldn't be happier with the results. 45 year old Lycoming O-320 never been apart 1,500 total time and one of the smoothest 4 bangers I've flown after the carb and induction system work.
 
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bnt83 said:
My $0.02. #1 The one piece venturi does NOT work well with the old style discharge nozzle.
#2 When you get a new or rebuilt carb, you MUST ensure the entire induction system is tight or you WILL be chasing your tail.

Got a rebuilt carburetor from Avstar last year, replaced all the intake manifold gaskets & tube rubbers and sealed the leaking sump pipes (lycoming sump) and couldn't be happier with the results. 45 year old Lycoming O-320 never been apart 1,500 total time and one of the smoothest 4 bangers I've flown after the carb and induction system work.
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Lycoming's heated sump does not suffer the rich running tendency that the 0-200 with the remote mounted carb. does.
 
Tom-D said:
Lycoming's heated sump does not suffer the rich running tendency that the 0-200 with the remote mounted carb. does.
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This thing ran like crap before, solid, passes mag check but vibrations and didn't lean well. After the owner installed new spark plugs and a harness and a prop balance and didn't solve the problem he started asking about a carburetor. When I researched I couldn't prove his existing 10-3278-32 was even the right one. We traded for a rebuilt 10-5217, sealed the induction system up, what A HUGE DIFFERENCE.
 
Policeboss said:
I just wanted to give a quick update on my vibration problem. I also wanted to say thanks to Tom D. I ended up purchasing the used carb in the pictures and replaced the New carb that was installed just before my problem began. The new carb being a one piece Venturi and the used one being a two piece. Swapping the new for the old one fixed my problem. Thanks again to Tom D and the others here that helped point me in the right direction.
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I don't know about you but I would surely think twice about keeping the A&P who sent you on this while ride....It is not like this is a new problem or an unknown one. Your mechanic should know this.
 
Tony_Scarpelli said:
I don't know about you but I would surely think twice about keeping the A&P who sent you on this while ride....It is not like this is a new problem or an unknown one. Your mechanic should know this.
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Unless "other" A&P's /IA's didn't submit service difficulty reports to the FAA....:dunno::dunno::mad:
 
N801BH said:
Unless "other" A&P's /IA's didn't submit service difficulty reports to the FAA....:dunno::dunno::mad:
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I guess its too much to expect that they might have worked on a 150/152 before or any kelle aerospace carb on 172's, Cherokee's.....

I have read this exact problem on three different pilot forums and two Cherokee forums and I am not a mechanic.
 
N801BH said:
I don't get it...:dunno:..

Why should A&P's, IA's be vomiting :vomit::vomit::vomit:....

Shouldn't it be the poor customer who got screwed. :dunno::rolleyes:
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Parts arriving DOA (dead on arrival) is not that uncommon. Carburetors are suseptible to shipping upset which will be found at installation as the float/needle will be stuck...

Kelly Aerospace carburetors themselves having issues, first I've ever heard of it. :dunno:

Talk to the overhaulers themselves before you buy an overhauled carb. Knowing the engine it's installed on from the get-go can prevent setting problems.
 
Tom is ded on about the rebuilt Kelly carbs.
Most times all they need is accelerator pump, and a good cleaning.
Mine also needed the pump discharge valve. It already had the one piece venturi.
I did replace the float IAW MSSB (I forget the number) with the blue epoxy float.
The total cost of parts and gaskets was less than half the cost of a rebuilt from Kelly. And downtime was a day or so.
 
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bnt83 said:
This thing ran like crap before, solid, passes mag check but vibrations and didn't lean well. After the owner installed new spark plugs and a harness and a prop balance and didn't solve the problem he started asking about a carburetor. When I researched I couldn't prove his existing 10-3278-32 was even the right one. We traded for a rebuilt 10-5217, sealed the induction system up, what A HUGE DIFFERENCE.
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Would you believe any engine would run sweet with the wrong carb, and induction leaks?

the MA3-SPA carb has many different part numbers dependent upon the make and model engine.

I know of two different owners that tried to run C-150/0-200 carbs on a C-172/0-300 neither worked well.
 
N801BH said:
I feel real bad for the OP, as he has already bet his hard earned money on a FAA certified carb, only to find out by several FAA certified A&P /IA's that Kelly produces junk, and that fact is well know throughout the inner circle of mechanics and for some reason no one is giving the FAA the feedback I thought A&P's were bound by law to provide..:dunno:
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Ben I'm sorry I missed this post the first time thru the thread, But my question to you is simple, What makes you believe we have not been bitchin about this to the feds since 1994?

Why do you think we have had 4 different re-writes on these ADs?
 
Tom-D said:
Ben I'm sorry I missed this post the first time thru the thread, But my question to you is simple, What makes you believe we have not been bitchin about this to the feds since 1994?

Why do you think we have had 4 different re-writes on these ADs?
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If all you A&P's and IA's are sending in the Service Difficulty Reports and nothing is getting done to fix an obvious Quality Control problem at Kelly then I have to assume the FAA is sleeping at the switch... Since this site has a narrow audience and there clearly is an issue, one would think that worldwide the SDR's stretch into the hundreds. Is there are place a person can go to on the Internet and view all those Service Difficulty reports..... Seem to me it would be public record and available for all to see.
 
N801BH said:
If all you A&P's and IA's are sending in the Service Difficulty Reports and nothing is getting done to fix an obvious Quality Control problem at Kelly then I have to assume the FAA is sleeping at the switch... Since this site has a narrow audience and there clearly is an issue, one would think that worldwide the SDR's stretch into the hundreds. Is there are place a person can go to on the Internet and view all those Service Difficulty reports..... Seem to me it would be public record and available for all to see.
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This problem with the MA3-SPA carb did not start with Kelly, It started with Precision Air motive, in 1990. when they used 7 carb failures in 40 years of this carb being in service to gain an emergency AD to replace all 2 piece venturies, that started a chain of events that lead to the AD being re-written 4 times.
What they tried to do was sell parts thru the AD system, and it nearly bankrupted them, because they got sued by several operators, so they sold the production certificate to Kelly. Now Kelly has re-designed the carb to use plastic floats, 1 piece venturies, different atomizers, and several other modifications.

The old brass floats, steel inlet shut off needles, and the old atomizers are getting way difficult to find. And these are what is needed to run auto fuel in these carbs.

When you run auto fuel in the new Kelly carb, they will not honor their warrantee.
 
Tom-D said:
This problem with the MA3-SPA carb did not start with Kelly, It started with Precision Air motive, in 1990. when they used 7 carb failures in 40 years of this carb being in service to gain an emergency AD to replace all 2 piece venturies, that started a chain of events that lead to the AD being re-written 4 times.
What they tried to do was sell parts thru the AD system, and it nearly bankrupted them, because they got sued by several operators, so they sold the production certificate to Kelly. Now Kelly has re-designed the carb to use plastic floats, 1 piece venturies, different atomizers, and several other modifications.

The old brass floats, steel inlet shut off needles, and the old atomizers are getting way difficult to find. And these are what is needed to run auto fuel in these carbs.



When you run auto fuel in the new Kelly carb, they will not honor their warrantee.
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I see the dilemma Tom......

If I had a certified plane with an autofuel STC, I can guarantee you I would fight Kelly,, tooth and nail over the fact they sold a carb that was NOT airframe complaint.....

Ps... Care to tell me where to go looking for all those Service Difficulty Reports you guys sent to the FAA?

Thanks in advance..
 
N801BH said:
I
Ps... Care to tell me where to go looking for all those Service Difficulty Reports you guys sent to the FAA?

Thanks in advance..
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Not a clue.
 
Tom-D said:
Would you believe any engine would run sweet with the wrong carb, and induction leaks?

the MA3-SPA carb has many different part numbers dependent upon the make and model engine.
QUOTE]


NOPE! They wouldn't

I couldn't prove that the carburetor was ever removed either. By the records it looked to be factory installed, so I asked around to see what other owners had on their same make/model/engined aircraft (since the TCDS just says MA4-SPA), and none of them had the carb that this engine had. Engine parts manual conflicted with a much later dated Service Instruction so we installed the SI part #.

Per the carb shop the 10-3278-32 runs MUCH richer. Maybe they were trying to mask induction leaks or cooling problems long ago? :dunno::mad2:
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bnt83 said:
I couldn't prove that the carburetor was ever removed either. By the records it looked to be factory installed, so I asked around to see what other owners had on their same make/model/engined aircraft (since the TCDS just says MA4-SPA), and none of them had the carb that this engine had. Engine parts manual conflicted with a much later dated Service Instruction so we installed the SI part #.

Per the carb shop the 10-3278-32 runs MUCH richer. Maybe they were trying to mask induction leaks or cooling problems long ago? :dunno::mad2:
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More probable they was a spare MA3-SPA setting on a bench when they needed one. and an attitude that they are all the same.
 
Thanks for all the information. Just for future visitors....

Cessna 150j ran great and one day, we had noticeable vibrations at lower RPMs. Mechanic asked us to run engine for around 30 seconds and test temperature of each cylinder with touch or laser thermometer.

Cylinder 4 was 100 degrees cooler than the others.

It turns out the intake gasket had blown out. Intake pipe was little loose. Didn't realize it at first but upon further invigilation, we found it to be loose.

Hope that helps future pilots troubleshoot.
 
FritzSmith said:
Thanks for all the information. Just for future visitors....

Cessna 150j ran great and one day, we had noticeable vibrations at lower RPMs. Mechanic asked us to run engine for around 30 seconds and test temperature of each cylinder with touch or laser thermometer.

Cylinder 4 was 100 degrees cooler than the others.

It turns out the intake gasket had blown out. Intake pipe was little loose. Didn't realize it at first but upon further invigilation, we found it to be loose.

Hope that helps future pilots troubleshoot.
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Just to update, the new carbs that are on the market now have the rich running problem fixed. I've changed two in the past year both ran well, even the idle and idle mixture were right.
 
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I hate to break into a carb thread, but are Kelly's overhauled Slick mags of similar quality?
 
Does anyone have contact info for Tom-D, I'm in need of a repair/rebuild on a carb.
 
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