Difficulty restarting engine.

[Mr-d]

Our engine starts fine first when its cold, pull out choke, pull.. it ticks and stops, slam choke back in, pull.. and it runs... However, after it is ran warm, and stopped (i go fishing) 30 min later i decide to move back up due to drifting, and it wont start... pull 3x normally, nothing happens, pull out choke again and thing backfires (Pulling the start cord back in REALLY hard, it hurts!) Stick the choke back in.. and it still backfires... leave it for another 3 min (by which i am almost hitting the rocks..)<br />try to start it again, with choke off pull it 3x, nothing happens, 4th time it backfires and then 5th time it starts running, only on one cilinder....... Rev it up, 2nd cilinder engages and thing runs fine, until you stop it next time...<br /><br />It's a Merc 200 from 1978, 20HP, twin cil.<br /><br />Any ideas as to what might be causing it, i suspect it is a highly carbonated piston.<br /><br />Thanks,<br />Daniel.

 

[WillyBWright]

Re: Difficulty restarting engine.

I'm suspecting water is getting into the lower cylinder. Not a lot, but enough to squelch the explosion until it clears out. If you ever severely overheated it, it could have a cracked cylinder. It could also come in from a bad lower crankshaft seal. If it is water, you'll be able to see it on the sparkplug, or you will see a significant difference between the deposits on the two sparkplugs. The cleaner one would be the problem cylinder. Sometimes the deposits are speckled, sometimes you can find rust.<br /><br />Your float valve may be leaking and the gas ending up in the bottom cylinder. That would flood just one cylinder and it would run on the upper until it cleared out. That could also be the result of a leaking fuel pump diaphragm.

 

[Mr-d]

Re: Difficulty restarting engine.

Update.... <br /><br />Got engine started today (from cold) with hooooge trouble. Pulled out choke, attempted to start it 3x, took 3x before it fired briefly. Stuck choke back in, pulled 3x, backfired 2nd time and started 3rd time... Went out (running on only once cilinder...) 2nd cilinder engaged every now and then... and i slowed down to allow a passenger to come further towards the back, it imediatly shut down one cilinder when i slowed down, and now the second cilinder started to sputter and fire irregularly. and i went to WOT to solve it, and nothing happend... it then stopped..... and wouldn't restart... <br />Upon trying to start it i've had backfire (Through exhaust, nice water feature, might i add.)<br /><br />and the starting cord jamming up upon pull and reversing itself REALLY hard (I've still got all my fingers..)<br /><br />So, it refuses to restart, i've given it 5 min cooloff periods, but it still wont start... i think im going to take it to bits and get all the seals replaced, the impeller replaced (Might as well), get a new seat for the carb needle..<br />maybe some new spark plugs if i can find them... <br /><br />The hardest thing has got to be telling my dad that i want to take it to bits, he is one of the preaching types that says that only bad things come from taking engines to bits, because you never know WHAT has been changed/messed with.<br /><br />He tried to outsmart me today (infront of some friends) by telling me how to work the boat... like i dont know how to work the boat.. he has never even been out on it by himself, or even controlled it.