Ignition Tune Up

['61star_craft]

Ihave a 1961 Lark3 40hp model #35525 that i bought 3 years ago, when i bought it I replaced the fuel lines, impeller, and thermostat an it ran excellent. The first time i took it out this year it ran like crap, dident want to idle very well and had no power from about half throttle on so i figured i needed to throw a carb kit at it. When I was taking the carb off i decided to see what the coils looked like. I was surprised to find them in what i think is very good condition. The contacts on one set of points were touching (closed). How old do you think the coils are by looking at them and would you replace them since the flywheel is off ( that was fun by the way). And what about the points. Thanks in advance.

 

[coolguy147]

Re: Ignition Tune Up

clean the points up with 400-600 wet/dry sand paper

set them to .020 gap

not sure on the coils...there are no cracks?

 

[todd57]

Re: Ignition Tune Up

One of the points is always going to be closed if the other one is open. There is a cam that slides down over the crankshaft, and that cam controls when the points breakers open. As the crankshaft turns, the high point on the cam turns, and when the high point hits the rubbing block on the breaker, the breaker opens and the spark plug fires. You'll want to set the point gap when the rubbing block is at the highest point on the cam. If you want excellent timing, then you can get one of the timing fixtures from F_R and set the points to open when the pointer is between the two timing marks. It is important to remember that timing the engine is about WHEN the points open, and not how WIDE they open. The spark is sent to the plug immediately when the point opens. They give you the point gap spec, because most people don't have the special tool, so that is a good reference point to use so your points open at the proper time.

 

['61star_craft]

Re: Ignition Tune Up

Hey thanks alot guys. Do you think the coils are fine, there are no cracks.

 

[todd57]

Re: Ignition Tune Up

I would try it after the carb kit. Be sure you soak your carb overnight in carb dip. Remove all the core plugs in the carb too, so ALL the gunk gets out.
Also, I would clean that grease off your crankshaft before putting your flywheel back on. You don't want any greasy or oily stuff between the flywheel and cranshaft mating surfaces. It's a friction fit. It has to be a dry fit, or your flywheel may slip and shear the key.

 

[kfa4303]

Re: Ignition Tune Up

Hi '61. Welcome to iboats. I would also clean and readjust the points to .020" when the cam is in the TOP position, or better yet just replace them. You can get a tune up kit right here at iboats for about $15. Some new 7mm, copper coil spark plug wires will make a world of difference too. You can usually buy it buy the foot at autoparts stores like NAPA for about $3 a foot. With that you'll have a virtually new ignition. I circled one little spot on one of the coils that looks a little fishy, but it may be nothing. It looks like it may have been worn and repaired at some point. Otherwise she looks good.

 

['61star_craft]

Re: Ignition Tune Up

Thanks kfa, that wire does look a bit odd, can't tell if it got melted or was repaired with that liquid electrical tape. I think ill replace the coils for peace of mind. What is the best cleaner to soak the Carb in, and what brand of parts do you recommend from iboats. Thanks again for your help.

 

[todd57]

Re: Ignition Tune Up

I just used some Berryman's Chem Tool Carb dip this week. First time I've used it. It comes in a gallon paint can, and has a plastic basket strainer in it. It made my carbs look like shiny brand new ones. And got rid of the nasty gunk that was in the bottom of the float chambers from my dad leaving fuel in them for 7 years.

 

['61star_craft]

Re: Ignition Tune Up

Ok, picked up some Berrymans Carb dip ill give that a try tonight. Went to the local Evinrude shop to get a carb kit because i dont want to wait for shipping, all they had was a kit for a 1964, part #439075, he said it would work on my carb but im not so sure. Does anyone know if it will work for a 1961 Lark3 40 horse?

 

['61star_craft]

Re: Ignition Tune Up

anyone?

 

[Daviet]

Re: Ignition Tune Up

What is the part number for your carb kit for the 1961?

 

['61star_craft]

Re: Ignition Tune Up

Cant find an OMC part number, only a Sierra part #18-7010, and comes without a float.

 

[Daviet]

Re: Ignition Tune Up

According to the site I looked at, 439075 crosses to a sierra 18-7024. Look at the site below and compare a 18-7010 to a 18-7024. they look different to me, but I have been wrong before.
Do you need a float, maybe the serria kit will work for you.

 

[todd57]

Re: Ignition Tune Up

NAPA Auto Parts sells both kits for $25 - $28. Here are the pics for both of them. I agree with DavieT. They don't look that similar. I guess you can compare them to what you have to see which one will suit you better.

 

[kfa4303]

Re: Ignition Tune Up

Hello again '61. Either kit will probably work. They often come with lots of parts that you don't necessarily need for your particular motor due to all the different models. The pic on the right looks more typical of carb kits for motors of your era, but if you look close the pic on the left has all the same bits as the pic on the right except for the little bag filter, which I've never used. Either should work, but you may have more leftover parts if you use the kit on the left.

 

['61star_craft]

Re: Ignition Tune Up

Hey thanks alot guys, I had no idea that NAPA sold parts for my motor. Kfa you said you have never used the bag filter, did you remove it or just clean and replace it? Thanks again.

 

[todd57]

Re: Ignition Tune Up

Yep. I call them when I'm in a hurry to get the parts. I live in West TX, and pretty much any Sierra parts I order can be here the next day from Dallas. They get a truck every day. I just have to call them before 5:30 PM. I already have the Sierra part number usually, and just give that to them. It's like overnight delivery, and I don't have to pay the delivery fee.

 

['61star_craft]

Re: Ignition Tune Up

Thanks, I just ordered the coils and condensors, local johnnyrude dealer had the points, the coils and condensors will be here tomorrow, never would have thought of NAPA.

 

[todd57]

Re: Ignition Tune Up

Me neither. 'Til I read it on iboats one day.

 

[tonk62]

Re: Ignition Tune Up

in the picture it looks to me like one of the coils has some melting on the ground wire, one of the condensor also appears to have melting around the top of it.