56 big twin 30hp won't start

[tinker2584]

This moter was given to me by a freind. I't sat in his basment for 20 years.
Strong blue spark, strong battery, 100 psi compression, fuel in getting to spark plug. Set high speed one turn out, low speed one and a half. Engine will not fire at all. Any ideas???
Thanks
Frank

 

[tashasdaddy]

Re: 56 big twin 30hp won't start

go here http://forums.iboats.com/forumdisplay.php?f=31 read outboard won't start, and awakening a sleeping outboard, Joe Reeves carb setting.

 

[samo_ott]

Re: 56 big twin 30hp won't start

If you got spark, compression and fuel, it has to fire... it's physics... unless the spark arrives at the wrong time... have you tried spraying premix in the carb to see what happens? Does the carb open up when the timing plate moves?

 

[jbjennings]

Re: 56 big twin 30hp won't start

Frank,
just asking so I can get some important info.......
How stong is the spark? what kind of gap does it jump?
Also, how do you know you're getting gas to the plugs?

Here's something to try......If it's a reed valve stuck open due to a bug or whatever (super rare!!!!) it will keep the cylinder from getting fuel. Try squirting a little fuel/oil mix in the spark plug holes and see if she'll fire. If it does, carefully take off the carb. and use a flashlight to look in the intake manifold to see if any of the reeds are stuck open.

Sometimes the spark will look good outside but won't actually be stong enough to fire inside the cylinder.

One more question. will it pop, backfire, or do anything at all?
Good luck,
JBJ

BTW, I wish I had friends with free big twins in the basement!

 

[tinker2584]

Re: 56 big twin 30hp won't start

Thanks for your replys.I'll give some more detail.
All linkage works properly.Squirted premix into cylinder still wont fire. Sparks a bright blue in J4J plug. I will test the plug spark jump.
I will post back shortly with results.

Thanks,
Frank

 

[JB]

Re: 56 big twin 30hp won't start

Check your flywheel for a sheared key.

 

[F_R]

Re: 56 big twin 30hp won't start

Checking for spark across the plug gap is worthless. It must jump a 1/4" gap.
You might have it flooded. 1 turn open is too much. 5/8 turn is more like it. And then you come along and squirt even more gas in it to flood it worse yet.

 

[tinker2584]

Re: 56 big twin 30hp won't start

I checked the spark gap. It will only jump about 1/16"!!! I suppose thats the problem.Pulled the flywheel and key is OK, but the plastic cases around the coils are cracked. Could that be giving me a weak spark?
Frank

 

[freddyray21]

Re: 56 big twin 30hp won't start

cracked coils will give a weak or non existant spark. replace them and she will more than likely run

 

[jbjennings]

Re: 56 big twin 30hp won't start

I checked the spark gap. It will only jump about 1/16"!!! I suppose thats the problem.Pulled the flywheel and key is OK, but the plastic cases around the coils are cracked. Could that be giving me a weak spark?
Frank

As Freddyray said, cracked coils are a textbook no-nol for those motors and why it's always best to check them right off the bat on a motor that old. I even have begun to EXPECT to see them. Replace
'em and you'll have a nice motor...It will suprise you how easily it cranks and how smooth it runs!
GOod luck,
JBJ

 

[samo_ott]

Re: 56 big twin 30hp won't start

I checked the spark gap. It will only jump about 1/16"!!! I suppose thats the problem.Pulled the flywheel and key is OK, but the plastic cases around the coils are cracked. Could that be giving me a weak spark?
Frank

But in your first post you said they had a strong blue spark!

 

[tmcalavy]

Re: 56 big twin 30hp won't start

A coil on its way out can occasionally throw a blue spark, but the end is near if the case is weeping or cracked. I've got a Merc Mark 7 in the shop with dicey coils, it runs good when it wants to, but a complete coil replacement is coming soon. If yours are cracked and you like the motor enough to keep and run it, replace anything that looks worn while you've got the flywheel off...coils/points/condensors and check all connections. That's a motor worth keeping if you like it.

 

[tinker2584]

Re: 56 big twin 30hp won't start

The plugs do fire a blue spark. I assumed that a weak spark would be orange.
I live in Canada, any recomendations for cheap parts?
Thanks again for your replies and comments.
Frank

 

[samo_ott]

Re: 56 big twin 30hp won't start

Frank, where are you in Canada? I get my coils at the dealer for around $35 each last time I bought em... Or you can mail order them

 

[tinker2584]

Re: 56 big twin 30hp won't start

Steve, I'm in Oshawa.I'm going to check NAPA tommorow.
Frank

 

[samo_ott]

Re: 56 big twin 30hp won't start

There's also a mail order place in BC that WBeaton gave me the link for but I cant find it. PM him if you want it.

 

[tinker2584]

Re: 56 big twin 30hp won't start

Bought the coils at a local NAPA store. Installed them and it fired right up!Just have to set the carbs up. Thanks everyone!
Frank