1985 15hp no start condition

rpemp

Recruit
Joined
Aug 21, 2007
Messages
3
Hi all:
I bought this O.B. recently and can't get it to fire. Pulled the plugs and it's getting spark. "Seems" to be getting fuel because the plugs were wet, so I gave them a hit with emery cloth, blew them dry with compressed air and re-gapped to .35 (because I'm not sure what they should be at yet). When grounded to the block the plugs seem to fire fine though (blue spark). It doesn't even act like it want's to fire though. While it makes me cringe to do it, I even gave it a shot of starting fluid after drying the plugs out and...nothing, not even a burp.
The last owner said it was running and died suddenly and he couldn't get it restarted, he was trying when the the recoil retaining spring came off (for the second time) and he took it back to the local boat shop who'd "fixed" it the first time. They assymbled it wrong again (twice...scary eh?). Then he called me and I saw the problem after two minutes under the hood so the recoil works fine now. He got tired of being broke down on the lake and ordered a new motor and I ended up buying this one.
I was thinking ignition issues, but I'm not so sure anymore. I'm not afraid to dig into it, but this one's got me stumped...seems to be getting fuel, air, spark...so it SHOULD fire...but wont.
I asked what fuel ratio he was running and it sounded like (and looks like) at least 50/1. I'm fairly handy with a wrench so I'm willing to dig into it myself, so any advice or input would be greatly appreciated.

Thanks...Rob
 
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freddyray21

Commander
Joined
Jun 10, 2006
Messages
2,460
Re: 1985 15hp no start condition

it needs three things to run, spark , fuel and compression all at the appropriate times. I don't know on that newer model if it has points, but if it does check the points and see if they are gapped properly. If the gap has slipped a little it will affect timing and it will fire at the wrong time. Do a compression test and find out what the compression is in both cylinders. Assuming the compression is good. Look in your manual (if you don't have one buy one or get one from the library) and check the link and synch. Basically it is how you time them. I had a similar problem recently with an 18 hp and it turns out that is what it was.
 

iwombat

Captain
Joined
Jul 12, 2006
Messages
3,767
Re: 1985 15hp no start condition

The '85 has a power pack I think.

Just because the plugs spark laying against the block doesn't mean you've got good spark under load. You need to get or make a spark tester and to a proper spark check.
 

Xcusme

Commander
Joined
Apr 21, 2003
Messages
2,888
Re: 1985 15hp no start condition

Rpemp, Welcome to iboats!

Previous owner said it died suddenly, wouldn't restart...etc. Sounds like you may be correct about an ignition problem. Using a harmonic balancer type puller, remove the flywheel and check for a sheared or partially sheared flywheel key. It wouldn't be a bad idea to get some compression numbers while you're at it.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 1985 15hp no start condition

i agree with the flywheel key. if it has compression. besides the puller you need 3/ 1/4 x 20 #8 hardened bolts (auto parts store) regular bolts will strip off in the flywheel.
 

rpemp

Recruit
Joined
Aug 21, 2007
Messages
3
Re: 1985 15hp no start condition

Man...you guys called it. Pulled the flywheel to find it was 180 off and the woodruff key was sheared. I changed it out and it fired right up. Thanks for the input and support! Was kind of concerned that the nut on the flywheel can come loose like it did so I gave it a liberal dose of high strength locktite before nailing it with an impact wrench. If it were to happen again I believe I would drill the nut and safety wire it (like we did on everything back in the aircraft maintenance world), but I think it's good to go now.
Thanks again all! (Now about that 61 40hp v-twin I'm working on for my pop...) :)
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 1985 15hp no start condition

love those older motors. most likely the points, coil, condeners, plug wire, carb rebuild, and impeller. all can be had at laingsoutboards.com. probably around $175. if it has good compression, change everything out, and it should be a new motor. i just did a 57 35 hp.
 
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