Ignition problems...

[_brad_]

1977 Evinrude 70 HP

I get spark on all cylinders however I do no get a drop in RPM when I pull the bottom boot off the plug while running. There is smoke consistently coming out the lower carborator which I think means its not burning the fuel..

I have tried replacing the spark plug for the cylinder without any luck.

This is the first time I have attempted to diagnose an ignition problem past the spark plugs so could use some help. Are there any ways to test the coils and power pack with a regular meter? I want to try and get any parts I need prior to the local shop closing for the weekend.

Any help would be great!

#130 PSI on all cylinders.

 

[tashasdaddy]

Re: Ignition problems...

if you are getting smoke out of lower carb, i suspect reed valves behind the carb. what do the plugs look like?

 

[_brad_]

Re: Ignition problems...

Yeah, its like smoke and fuel spraying out. Definetly smoke though...

Plugs look wet. Nothing but wet..

I just checked and I am getting 1/2 inch spark on all cylinders....

 

[lexkyboater]

Re: Ignition problems...

I've read a way to test reeds per manual is to put a business card over the carb intake and if there's a lot of gas getting blown back on the card, there's an obstruction on the reeds, or one is broken/bent. Normally, the card should just have a mist of gas on it if the reeds are working right. Sounds like you've pretty much found that already though. The manual for a 68 - 72 9.5 HP says the reeds should be seated lightly against the cage, but a 1985 Johnson 150 HP should have a .010 inch gap between the reeds and cage.

 

[_brad_]

Re: Ignition problems...

Yeah its spraying pretty good and is fogging though the carb.. This all started when I was going WOT for about 30 min and all of a sudden it bogged down.

Symptoms are the same now as they were then.

-Good spark on all cylinders
-Fuel to all cylinders
-#130 PSI compression on all three

Holly crap I just thought of something! I had a post a little bit ago about a hissing noise I was hearing when I would remove all spark plugs and cover the bottom plug (same cylinder in question here) and turn the flywheel I would hear a "hissing" noise coming from the other plug holes...

Could this have anything to do with anything? Are reeds $$$???

 

[F_R]

Re: Ignition problems...

You may as well pull the intake manifold and take a look at the reeds but I suspect you have something far more serious going on that may have damaged the reeds in the process. You never know till you look.

 

[mikesea]

Re: Ignition problems...

do compression test too,but I agree with a reed problem

 

[_brad_]

Re: Ignition problems...

I cant seem to find them here on Iboats... Any thought's where I can find one? Expensive?

 

[F_R]

Re: Ignition problems...

Near as I can tell the part number is 382442 (for one cylinder). Lists for $106.00. From a Johnson or Evinrude dealer. You will also need some gaskets. Verify that part number before ordering. I had trouble finding it. That is the 1976 number.

 

[Molaker]

Re: Ignition problems...

Near as I can tell the part number is 382442 (for one cylinder). Lists for $106.00. From a Johnson or Evinrude dealer. You will also need some gaskets. Verify that part number before ordering. I had trouble finding it. That is the 1976 number.

A 77 Johnson 70hp shows 0386798 superceeded by 0389731. The 76 Johnson shows the same as the 76 Evin that you found (382442). I'd guess the 0389731 is a better number. It is shown as $93.62 on ishopmarine.com + about $15 shipping, so it should be about the same at a dealer.

 

[_brad_]

Re: Ignition problems...

Alright, so does anyone know the correct part number for an Evinrude? Or will the 1977 Johnson 70 HP part number work for my Evinrude? What years will fit?

I see a 1978 75 HP johnson/evinrude reed set on ebay but dont know if it will fit or not...

Also, anyone know the correct reed gap this year is supposed to have?

 

[mikesea]

Re: Ignition problems...

Brad,,99.999 % positive they will work,but,take yours off first,if you broke a reed off and its floating around the engine,you could be in for more trouble,thats why I suggested a comp.test,in the event a missing reed got into a cyl ,good chance its just a bent one,or that of it is broke it stuck somewhere before the cyl.I rebuilt alot of 3cyl.and dont recall any differance with reeds or intakes for pre,VRO engines,but I have been out of it a while.Surely there are used intakes around for alot less than the cost of just a reed set,if you are looking to save $$$