9,9HP Evinrude missfires

[andm]

Hi !
I have a 9,9 HP 1986 Evinrude that missfires when I increase the rpm`s.
I change to a new carburator last year but the problem still remains.
I took of the flywheel as I expected to find some points to check, but I just find out that there are no points.
Anyone have any idea of what I could check or do ?

 

[Joe Reeves]

Re: 9,9HP Evinrude missfires

What do you mean by "missfires". Drops a cylinder completely, a cylinder cuts in and out, what?

 

[mikesea]

Re: 9,9HP Evinrude missfires

check the timin cam,under the flywheel,it is what sincs fuel and spary,they break,also the roller will wear

 

[boobie]

Re: 9,9HP Evinrude missfires

As Joe said, we need more info ???

 

[the machinist]

Re: 9,9HP Evinrude missfires

Welcome to iboats forum.
As Joe says we really need more info. Is the new carb from the same year motor? Is the carb throttle cam roller the same size as the original, if not then your timing could be off. You might have a coil that is going bad & occasionally dropping a cylinder. Even a bad spark plug wire, usually at the plug connection. Could even be in the fuel supply system.

 

[andm]

Re: 9,9HP Evinrude missfires

I thought I reply yesterday, but it seems like that got lost somewere.
I change the carburator to a 15 hp carb, but the camroller is the same.
I change the carburator beacause the old one was dammage inside, the float had come loose, probably due to saltwater inside that had made the float joints/seat go away.
The motor behave in the same way with the old carburator and I thought that the loose float was the reason, but the problem remains with the "new carb".
I change the sparkplugs at that time also.
Today I have change the sparkplug wires, but the problem still remains.
The motor starts fine, but when I start to give trottle under load it seems to misfire in the mid register, at full trottle it worked fine.
I will change the sparkplugs one more time, if I unfortunatelly had got a bad plug.
Anybody know what plug that is recomended ?
I have used NGK BR6HS.
Ignition problem or fuelproblem ?
(the carb I swapped over to was a used one)

 

[nwcove]

Re: 9,9HP Evinrude missfires

i would start by switching to champion plugs ( model # of engine?). omc motors seem to not like the ngk plugs. also how would salt water get into the carb? did you clean and put a new kit in the 15hp carb?

 

[andm]

Re: 9,9HP Evinrude missfires

Model # is BE10BALCCD
Dont know how saltwater got into the carb as I bought the motor 2 years ago, but I suspect saltwater had dammaged the aluminium in the carb.
I cleaned the carb I now using, but dident use any kit.
So I guess changing to champion plugs will be the first step , as I put new NGK plugs in the first thing I did after I bought it.
But what champion plugs ?

 

[nwcove]

Re: 9,9HP Evinrude missfires

looks like QL77JC4. a kit for the carb is also a good idea. the "top secret file" at the beginning of this forum will tell you how to clean a carb properly , just so you can rule that out as an issue.

 

[gokart83]

Re: 9,9HP Evinrude missfires

I had the same problem. I tried all the cheap stuff too such as plugs, coils, wires, carb kit, etc.... Turned out to be the powerpack. Yes this is a $120+- part but it now runs like a champ and I still have a much cheaper than new motor that I can work on!

 

[the machinist]

Re: 9,9HP Evinrude missfires

Is this carburetor the metal or plastic topped version? Are you running this motor in a tank or on the boat in the water? Running in a small tank can make for a different outcome. Also if on a boat, what size a boat? Possibly your prop is the wrong pitch to handle the boat.

 

[andm]

Re: 9,9HP Evinrude missfires

Thanks for all the answers !
The motor behaved in the same way with the old faulty carb, that carb was a plastic topped version. If I remember it right this one has the metal topped version.
I run the motor on the boat, as it is har to detect this problem in a small tank.
I will start to change to champion plugs and pray, but I`m afraid that I will end up with the powerpack.
So can a faulty powerpack get intermittent function like this ?
I thought it would be dead or alive ?

 

[AlTn]

Re: 9,9HP Evinrude missfires

yes, the powerpack can cause intermittent ignition issues

 

[andm]

Re: 9,9HP Evinrude missfires

No luck, I changed the sparkplugs today but the problem still remains. The red start locking device also came out of order due to some spring probably got out of the correct position so I wasent able to pull the start rope.
So no boat tour during midsommereve (tomorrow) for me !!
I will probably have to shange the powerpack.
But can someone tell me what includes in the powerpack ?
Under the flyweel I noticed 2+1 coil and one brown thing that seems like a sensor or indicator. Then there seems to be two coils/units were the sparkplugwires runs from.

 

[mikesea]

Re: 9,9HP Evinrude missfires

If it idles and runs fine at wide open throttle,I doubt the issue is with spark,UNLESS,as the mag.plate under the flywheel ,causes the plug wir(s) to ground out at a point.Thats possible if there is a crack in the wire.You changed the carb,so I doubt its that since the problem remained with replaced carb.MAYB,you have an issue with the fuel pump.Usually ,they will flood out at idle,but ,weird stuff happens when the diaphram becomes cracked,or dried out.At this point,Id think about replacing it,ESPECIALLY if it has not been changed receintly ,AND,may have issues due to ethonol gas.You should be able to get a rebuild kit through this site.Or just purchase another.

 

[AlTn]

Re: 9,9HP Evinrude missfires

marineengine.com has diagrams of your motor's parts...google..leeroysramblings.com..9.9/15 hp. maintenance and repair and you'll find a wealth of information and pics that will cover many year models

 

[andm]

Re: 9,9HP Evinrude missfires

Many Many Thanks !
I will look into this, and thanks for great info at leeroysramblings.com

 

[andm]

Re: 9,9HP Evinrude missfires

Yes Yes Yes !
Bought a fuelpump repairkit including diaphram etc. No visible crack on the old one but maybe nit so flexible and some rost on a spring and dried out old gaskets.
assbled the parts from the kit and tried the motor today, and Yes it runs like a dream !
Thanks everybody for all surgestions and information !
Summer, sunshine and troutfishing ahead !

 

[nwcove]

Re: 9,9HP Evinrude missfires

good job! fishin sounds good!