Lee Jackson Posted September 27, 2013 Share Posted September 27, 2013 Hello all, I went up last night for my second flight. All was going swimmingly until my engine started to fade and die. I was holding the throttle on full power but it literally fades and dies - see video. I do manage to feather the throttle initially to give me a bit of power and then (after it dies) it does re-start, but then fades again. After I landed the engine started on the ground without issue and ran up and down the rev range without hesitation!?!? The engine is a Parajet Volution Macro 1. My suspicion is that there was a vacuum being formed in the tank as the cap was extremely tight to remove after I landed. Has anyone else had anything similar happen using a first generation Macro? And, using any clues within my shonky footage, can anyone else please give me pointers of how to work out what's up with my engine (from the way it fades)? [youtubevideo] [/youtubevideo]http://youtu.be/fPXNYK8ZnDg Many thanks Lee Quote Link to comment Share on other sites More sharing options...
Farmer_Dave Posted September 27, 2013 Share Posted September 27, 2013 Could be vacuum in the tank but at a guess I'd say they have an automatic breather in there somewhere. Engines usually get richer as you gain altitude but yours is more likely getting leaner by the sound of it. Check the Pop off pressure if you have a Walbro or other diaphram carb. Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted September 27, 2013 Share Posted September 27, 2013 The macro breather is built into the fuel cap, check it for blockages. It sound's more like a tuning issue to me but it's hard to tell from the video, just re-tune the carb, maybe time for a carb rebuild/clean depending on how many hours it's done? Tom Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted September 27, 2013 Share Posted September 27, 2013 Have you checked the plug? Quote Link to comment Share on other sites More sharing options...
Lee Jackson Posted September 27, 2013 Author Share Posted September 27, 2013 I checked the cap on landing and it was super tight to get off but I could draw air through it... so perhaps not that. I've also been told to check the diaphragm as my unit is getting on for 4-5 years old (I think) so this could have degraded. Does Parajet or anyone else for that matter supply a rebuild kit specifically for these carbs (sorry for my naivety)? At the moment my money is on it being a fuel starvation issue... but I'll attack it from all angles before that third flight. Thanks for your replies gents Oh, and yes the plug is perfect. Quote Link to comment Share on other sites More sharing options...
pete_b Posted September 27, 2013 Share Posted September 27, 2013 Very fine gauze filter in the carb is blocked with fine lint, take carb of and clean out. Quote Link to comment Share on other sites More sharing options...
Guest Posted September 27, 2013 Share Posted September 27, 2013 I second Pete's assessment SW Quote Link to comment Share on other sites More sharing options...
Lee Jackson Posted September 28, 2013 Author Share Posted September 28, 2013 Excellent, thanks Simon and Pete. I know you guys use these units loads with students, so I'll definitely strip and clean my carb. Many cheers Lee Quote Link to comment Share on other sites More sharing options...
irm750 Posted September 29, 2013 Share Posted September 29, 2013 Hi Lee I had exactly the same problem with my volution compact. Cleaning the carb would be the obvious first step, but before you take it off just check that the carb is firmly bolted down to the block by giving it a wiggle. I found that on mine the bolts were too long and so they bottomed out allowing the carb to be loose even though I did them up tightly. This allowed unmetered air in resulting in a lean mixture and overheating. Once the motor cooled down it would let me restart it. Grinding a few mm off of the bolts fixed the problem. Good luck, Ian Quote Link to comment Share on other sites More sharing options...
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