OzVMX Forum
Clubroom => Tech Talk => Topic started by: EML on November 21, 2012, 02:51:40 pm
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OK Stupid question time.
We have a China built genny in the shop that was diagnosed as having a bent/burnt valve so it was shelved and the customer went off to buy a newie.
Had some time today so the boys pulled it down and found it to be ok. The mower shop next door has since told us that the spark plugs that they come with break down intermittently and give the impression that it has dropped a valve. We usually have plugs that either go or not and nothing in between.
Now, it is based not so loosley on a Honda and I figure the timing marks should be similar. There are two holes in the cam wheel that should line up with the cam cover/head. Then there is a hole in the bottom case for a locking pin to hole the bottom gear to line them up. Only problem is it will only let all this happen at BDC not TDC. SAm I going crazy or can this be correct?.
ps the mower shop don't have anything to do with these motors -prolly for good reason- but hey the cost over a grand and we have 1 for next to nix.
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My young bloke had a spark plug problem with a Chinee genny, it sounded like it was rattling its bits off !!, the porcelain had came loose from the metal body, the metal bit came apart when he tried to get the rest out leaving the threaded portion behind, got that out and put in a new NGK , no probs.
Can't help with the timing marks, though.
Foss
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C'mon Vaughn its a single cyl 4 stroke just set it up so it looks right TDC and cam in the right place and jobs a gooden ;) i know your forking with us :-*
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Seriously Bill if that was the case i would take the piss-espec from you lot.
OK so find TDC, line up all available marks and pull the rope----pa pa pa p-
OK- we got spark -check.
we got fuel- check
pull the bloody rope -----pa pa pa pppppa
OK so must be 180 out. Start again but get the same results. FIIK.
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Grass hopper ... does it have compression at TDC ???
Get to top of stroke and apply air ...this will check if your valves are ok or timing is out by 180 .
Has it sheared the key way ??
pa pa pa pppppa .... heard that same noise come from a trolly one day :)
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Maybe that's it Oldfart, it's caught the dreaded desease from the Wasp.
Has heaps of compression, valves are nice, head gasket is sweat. No broken keyways. Plenty of spark.
Has a funky electric throttle set-up so could be something with that.
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It will be the low oil level switch hommy.
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What Davey said
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Yep as Davey and mavman have stated , the oil switch/watchdogs commonly shit themselves and default to engine no start. Tim754
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Have earthed it out with same result. We have a tell-tale on the plug that tells us we aren't loosing spark which is what the low oil switch would cut. Seems to be a fuel issue.