shaggydec Posted December 21, 2009 Share Posted December 21, 2009 Hi Guys and Girls Anybody had my experience with engine cutting out ? About to launch and get engine up to temp. then give it some revs to clear its throat and check thrust. Take off and climb for a minute or so then loss of power as though fuel starvation , dropping down to low tickover or stop . Hit the starter and straight up to max revs for about 10 secs , climbing but looking to land ! And repeat until back at home ! Once i managed to nurse it home feathering the throttle . I ve managed to safely land every time but its so frustrating . Im posting this cause it happened again today . Just to say it isnt the fuel or the mixture or fuel starvation because i ve checked all of those previously...its simply the spark plug failing ! After 85 hrs im now on my 4th plug . The fault shows no signs in previous flights when it runs well and never misses a beat...On landing today i spent 1/2 hr on the ground trying to get max revs but to no avail...so new plug and its like a new machine again ! So my query is why is it eating plugs and why after having bikes of all shapes and sizes did you hardly need to fiddle with their plugs ( apart from a few KH triples that carried a spare set under the seat ! Remember?) PARAJET VOLUTION Thanks Steve Quote Link to comment Share on other sites More sharing options...
pete_b Posted December 21, 2009 Share Posted December 21, 2009 What plug are you using? Is the end burnt at all? Is the air gap correct? What colour is it when you take it out? Quote Link to comment Share on other sites More sharing options...
shaggydec Posted December 21, 2009 Author Share Posted December 21, 2009 Hi Pete Standard plug..NGK B8ES Looks like its running slightly rich ...sooty , brown .... but nothing to suggest it failing...and gapped to 30 thou....Tried one of my old " spare " plugs today just to check and it wouldnt even fire up Quote Link to comment Share on other sites More sharing options...
paramotormike Posted December 21, 2009 Share Posted December 21, 2009 I had a less severe version of your problem on a Parajet. Mine was caused by dirt in the carb. It would stay in the lower areas of the carb filter, and then on running and continuoius high vibration (take off) it moved and blocked the main jet. A good clean of the carb filter mesh cured it for me. Cheers Mikey.. Quote Link to comment Share on other sites More sharing options...
fanman Posted December 21, 2009 Share Posted December 21, 2009 Integrity of the plug cap ok? Quote Link to comment Share on other sites More sharing options...
alan Posted December 22, 2009 Share Posted December 22, 2009 Hello Steve, After you fitted the new plug did you fly the machine and was it fine as i had a power loss problem that was none of the above. Quote Link to comment Share on other sites More sharing options...
irm750 Posted December 22, 2009 Share Posted December 22, 2009 Had this on my first and second ever paramotor flights! Possible causes - 1) Plug cap worn oval and loose due to vibration 2) Unmetered air entering the system when warm (cracked or warped head or damaged head gasket) 3) Unmetered air entering below carb as carb retaining bolts too long (tight when checked with an allen key but carb still loose) 4) Carb needs cleaning or service. Good luck. Best regards, Ian. p.s. Any news on the battery??? Quote Link to comment Share on other sites More sharing options...
mark_t Posted December 22, 2009 Share Posted December 22, 2009 Hi Steve after 85 hrs of use have you thought about the fuel filter inside the tank ( It may clog up and the vacuum it causes may find a week point in your fuel line and draw air in causing your engine to run lean and cut out through fuel starvation) hope this helps Mark Quote Link to comment Share on other sites More sharing options...
Phil_P Posted December 24, 2009 Share Posted December 24, 2009 Could be a vacuum building in fuel tank at full chat, that eases as revs drop. Check all breathers. I had similar with a ball bearing type non return fuel line valve that would actually shut off fuel in the 'forward' direction if the draw in the system was sufficiently high. Quote Link to comment Share on other sites More sharing options...
Guest Posted December 28, 2009 Share Posted December 28, 2009 I had a less severe version of your problem on a Parajet. Mine was caused by dirt in the carb. It would stay in the lower areas of the carb filter, and then on running and continuoius high vibration (take off) it moved and blocked the main jet. A good clean of the carb filter mesh cured it for me.Cheers Mikey.. Same here, I used Tony's high hours Parajet for the instructors course. The carb was full of gunk, a quick clean and she was purring again. SW Quote Link to comment Share on other sites More sharing options...
garyfreefly Posted December 28, 2009 Share Posted December 28, 2009 mine did the same as Phil-P .......check your breather... or it could be the shitty petrol from the garage your closest to (I know) because I got 25 liters of worthless crap from there and it went into the microlight......they said you shouldnt be be using our petrol to put into a flying machine......I said that you shoudnt be selling water and passing it off as petrol... ...never been there since...... Quote Link to comment Share on other sites More sharing options...
shaggydec Posted June 19, 2010 Author Share Posted June 19, 2010 Should have replied before.... The problem turned out to be a partially melted piston !...Many engine hours before the reed valve decided to spit a piece into to cylinder . I stripped the engine down and could nt find any damage apart from a few very minor nicks on the piston top which disappeared with a bit of Wet Or Dry .. It ran fine for many hours after relacing steel reed valve with a carbon fibre one . Then i encountered the problems i previously talked about...Called Parajet and they thought it was the settings on the carb...The piston must have received some damage which i had nt seen and the front had ever so slightly melted...sort of rounded a bit which took some finding . The bore was spot on so just replaced piston and rings and head gasket . Fine till next time ! Quote Link to comment Share on other sites More sharing options...
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