While im clutching at straws by suggesting this because it would be unusual at such low revs(ie compared to race engines) but if your ignition system isn’t breaking down (which it should during your static run) maybe a weak valve spring causing valve bounce(like i said clutching at straws). Have you tried a vacuum gauge to at least determine what side of the engine the breakdown is on?(remove the balance pipe between manifolds, block one side and put vacuum gauge on other then alternate comparing readings before and during breakdown). Another thought- it takes more energy to produce a spark under lean conditions, you may have a combination of problems. Cracks in the distributor cap(in the magneto)or a bad lead/plug/points/ capacitor as well as a carb issue leaning out at high revs. Did you find an issue with your fuel pumps? Do you have a kink in any of the metal fuel lines(or rubber for that matter)? Stuck needle and seat in one carb? Water in the fuel? Are the bearings in the magneto ok? Would love to know what you find
From: [email protected] [mailto:[email protected]] On Behalf Of Ian Mc Phee Sent: Saturday, 30 November 2019 10:05 AM To: DOG LIST Subject: Re: [DOG mailing list] Stromberg 150 CD3 air leak around the throttle axle Have not seen an issue. Maybe put some plasticine around it and do a ground run. I will keep thinking. Ian McPhee 0428847642 Box 657 Byron Bay NSW 2481 On Sat, 30 Nov. 2019, 08:30 Jarek Steliga, <[email protected]<mailto:[email protected]>> wrote: Hello, I am still struggling with my Limbach rough run at RPMs around 3000. Since my max static RMPs are ca 2700 the problem only becomes apparent on take off (I actually had to abort one take off while being already ca 100 m above the ground - a rather hair raising experience). After having replaced a perforated metering needle piston diaphragm with a new one I am back to square one in my detective work of what gives. The next suspect I am zeroing in on is a badly worn out brass throttle axle combined with the visibly enlarged hole in the carby body this axle protrudes through. Can the air passing through this opening affect the formation of underpressure inside the carby to the extent of producing effects above described? Any comment will be greatly appreciated as always Regards Jarek --------------------------------------------------------------------- You are subscribed to the Dimona Owners Group mailing list. To unsubscribe, send email to: [email protected]<mailto:[email protected]>
