76 johnson 85hp cd 4 ignition problem

engine runs on 2 cyls.has no power. check compression and all 4 are 120psi check spark and all have strong blue arc. funny thing is it seems to only be running on the two top cyls believe its #1 and #2<br />can pull plug wires off bottom cyls. believe #3 and #4 and motor keeps running on two top cyls. but if I pull plug wire off either one of the top cyls the motor will cut off. like I said have good strong spark on all cyl. there is just no change on 3 and 4 cyl.<br />plugs are new and firing <br />can someone help me figure out whats going on<br />mabe something wrong with power pack I have a single neon tester but book uses a much nicer 4 wire tester and im a little confused.<br />thanks in advance robbie

Re: 76 johnson 85hp cd 4 ignition problem

Fuel, compression, and spark make the world go round. You have compression and spark. Probably time to overhaul the carbs.

Re: 76 johnson 85hp cd 4 ignition problem

I think walker has nailed it; you are not getting fuel through the lower carb. The jets (orifices) are behind the two screws on opposing upper sides of the carbs, and direct fuel through tiny holes in the floor of the barrels. They are easily clogged.

Re: 76 johnson 85hp cd 4 ignition problem

I to run a 85 h/p same year and I lost number 2 at the start of spring and chased everything on this motor. I finally rebuilt the carbs and the miss left with the rebuild of the carbs. The low-speed jets were stopped up. Your engine should have the number 28 jets in them. Take the carbs off and soak overnight and blow them out install new parts and put it back together.

Re: 76 johnson 85hp cd 4 ignition problem

thanks guys for your help. you know what i'll be doing next<br />and i'll give you the news

Re: 76 johnson 85hp cd 4 ignition problem

What info do I need have off motor to order the correct carb kits or does someone know the part number. Im ready to start, I want to get on the water!

Re: 76 johnson 85hp cd 4 ignition problem

Model number, h/p