Having issues with a 2 liter boxer engine.

H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.

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914Driver
Posts: 39
Joined: Thu Nov 17, 2016 4:42 pm
Location: Saratoga, NY

Having issues with a 2 liter boxer engine.

Postby 914Driver » Fri Aug 10, 2018 1:09 pm

Limbach L-2000a with Stromberg-Zenith 150CD3 carbs. The plane's been sitting for a while before I bought it, I'm concerned that the logbook showed the valves being adjusted at 5 - 10 hour intervals. Compression was low so I adjusted the valves correctly (had to back the adjuster out 2 turns just to get them to relax). Ran it a bit, checked compression, ran it some more, check adjustment and the compression is now 120-140.

Timing is spot on, so what's the problem? It won't rev higher than 2500 RPM. Red line is 3k, but run up instructions are to go to 2750 for 30 seconds. The only other variable is the carb. perhaps some schmegma is lodged in the main jet? I put some Save the Baby type cleaner in the fuel tank, but that takes time to work.

Removing the carbs is a real pain, I guess I'm looking for an easier solution before going through all that. When I rebuild this type of carb for a 1966 Datsun I had, the kit came with a 45 minute video, not a good sign.....

Suggestions greatly appreciated.

Dan

914Driver
Posts: 39
Joined: Thu Nov 17, 2016 4:42 pm
Location: Saratoga, NY

Re: Having issues with a 2 liter boxer engine.

Postby 914Driver » Fri Aug 17, 2018 6:48 am

Carbs were pulled and cleaned. Kinda. More of a wipe down, the jets and orafices were clear.

Rats. More befuddled than ever.

chicagorandy
Posts: 107
Joined: Fri Sep 08, 2017 2:39 pm

Re: Having issues with a 2 liter boxer engine.

Postby chicagorandy » Fri Aug 17, 2018 7:29 am

You probably already have this in your files, but just in case:

http://constructeur-amateur-aviation-lo ... -carbs.pdf

User avatar
joey4420
Posts: 138
Joined: Tue Nov 22, 2016 8:25 am
Location: Cincinnati Ohio

Re: Having issues with a 2 liter boxer engine.

Postby joey4420 » Fri Aug 17, 2018 12:33 pm

Not that I am that knowledgeable on these things; but if the engine is running good at full throttle but just doesn't get to the RPM you want, could it not be the prop? Either too long or pitch is wrong?
Joey
Cincinnati OH
Sport Pilot
Ercoupe N99773


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