1972 mercury 9.8 will not start

[paddlen]

Re: 1972 mercury 9.8 will not start

well I got my insulaters today and installed them checked all connectoins were good .While testing for spark I had to change number 2 coil and all was good then I hooked up fuel and now it will still not start .I'm getting tired.

 

[redjmp]

Re: 1972 mercury 9.8 will not start

Well if you are sure you now have spark, try giving it a shot of gas down its throat and see if that starts it.
If it then dies after starting, you obviously have a fuel problem like a clogged filter..

 

[bktheking]

Re: 1972 mercury 9.8 will not start

Are you getting spark on both now?

 

[paddlen]

Re: 1972 mercury 9.8 will not start

I am getting what I think is good spark on both and still 110 lbs of compression on both cyls. I have sprayed mixed fuel in carb and then in each cyl after many pulls still no start . I am stumped every thing seams to check out but I seam to be missing something ???????

 

[redjmp]

Re: 1972 mercury 9.8 will not start

You mentioned in your first post that you sprayed some starting fluid and it fired up for a few seconds.
This tells me that you have at least some spark and proper timing.
Try spraying more starter fluid again and hopefully it catches and when it does be standing by with a squirt bottle of fuel and give it a shot while its running on the starter fluid.

The dry plugs you described earlier are a clear indication you are not getting fuel into the cylinders.

When you squirted fuel down the carb or into the spark plug hole, you may have flooded it.

Make sure you use fresh gas and not any of that ethanol or E10 or E15 mix. Don't even bother mixing oil in the fuel you are squirting.
It wont damage anything to run without it for a few seconds.

 

[jbjennings]

Re: 1972 mercury 9.8 will not start

If you have good spark that will jump at LEAST a 1/4" air gap on each plug, then it should start. Try squirting some fuel/oil mix, just a little, into the spark plug holes and see if it will fire up for a second or two. If it will, then you may have a broken reed, preventing the motor from getting fuel to the cylinders from the carb. If it still won't crank, then either your plug wires are crossed or the flywheel key is sheared and it's out of time. Just because the plug wires don't look like they're possible to be wrong, doesnt' mean they aren't. It could be the wires going to the coils are crossed. I can't remember how the ignition is on the '72 even though I own one. Last thing I can think of would be a really bad lower crank seal, but even with that being bad I'd think it would fire up and run, just run rough.
Good luck,
JBJ

 

[paddlen]

Re: 1972 mercury 9.8 will not start

Well again I thank you guys for your input and help .I will try these ideas out and see what happens I still have 5 mths to get this going by then the ice is just comming off the lakes

 

[bktheking]

Re: 1972 mercury 9.8 will not start

Good spark- don't use your spark tester on this system, I believe your plugs are surface gap plugs, IE- nothing to gap. Hold the plug to ground and have someone pull it over (use pliers unless you want to shock yourself), if the spark is nice and thick and blue you should be good to go.

As far as everything else is it possible that you swapped the wires around going to the coils, the trigger wires coming from the points to the coils. I know it is possible cause the wires are long enough, just a possibility thinking out loud. Did you have the cam off the crankshaft by chance? Just asking cause I had 6 hp motor given to me this summer. The PO had the cam off the motor. What I installed another powerhead I installed the cam on backward, I got spark but it would never fire. I flipped the cam around (advice from another forum) and it fired right up.

 

[paddlen]

Re: 1972 mercury 9.8 will not start

With regular and surface gap plugs the spark is good.I have not have the cam off of crank ,I think it is cast as part of the crank.The idea of trigger wires being mixed up might be I will check again even though I followed a diagram I have screwed up before and somtimes I am good at it.So thank-you and I will look at that again after the holidays.

 

[bktheking]

Re: 1972 mercury 9.8 will not start

It's not cast into the crank, it's a replaceable part but you didn't have it off so that's not it. Even if the carb did not function it should still fire up spraying fuel into the throat, something isn't right.

 

[paddlen]

Re: 1972 mercury 9.8 will not start

I have not fogot about my dear 9.8 I have just been busy and hope to get to it again .
Again thanks for all you help and ideas .

 

[paddlen]

Re: 1972 mercury 9.8 will not start

Well I had a friend of mine come over and we looked at the 9.8 and have decided that it is most likley the reeds because no fuel is still getting to plugs.We took off side exhaust cover and pulled and no fuel.So if I replace reeds may as well do pistons and rings and gaskets and I just don't think I want to get into it.So game over .Any one want to buy a old merc with lots and lots of new parts ? Thanks again I have learned alot from the people who helped me .

 

[pointandshoot]

Re: 1972 mercury 9.8 will not start

i got a 9.8 a while back that was a bit of a mess. to save my shoulder i took the re-coil starter off, grounded it to the block with mechanics wire and used a cordless drill with a socket in reverse to spin the flywheel over (had to cut a 3/8 extension in half to fit the chuck). might not be the answer to your problems, but it spins the motor over really fast and saves your sweat glands the workout. might spin it fast enough to fire even.

 

[bktheking]

Re: 1972 mercury 9.8 will not start

Sure, pm me a price lol.

 

[paddlen]

Re: 1972 mercury 9.8 will not start

well sold old 9.8 and boat and bought a new Lund A12 and a 2011 Mercury 9.9m four stroke "Problem solved" Thanks again .

 

[bktheking]

Re: 1972 mercury 9.8 will not start

well sold old 9.8 and boat and bought a new Lund A12 and a 2011 Mercury 9.9m four stroke "Problem solved" Thanks again .

You must have deep pockets!

 

[pikefisherman]

Re: 1972 mercury 9.8 will not start

Can I ask wear you found points for this and how much? mine are not the best but the lowest I could find them was 100.00 a set.

 

[bktheking]

Re: 1972 mercury 9.8 will not start

What's wrong with them? Are they black?

 

[62larkowner]

Re: 1972 mercury 9.8 will not start

ok dumb question on your coils you have red on positive on top coil white on negitive top coil, green on positive on bottom and brownish tan on negitive right? what about your kill switch wire ( brown i beleave) is it hooked up properly?



top coil

 

[bktheking]

Re: 1972 mercury 9.8 will not start

Believe it or not the kill circuit works backward on these motors, the kill wire needs to be grounded to get spark as opposed to most motors which ground out to kill spark.