air silensore cover box

[canman]

hi guys . i found out if i leave the cover box off of the carbs my motor seems to run a lot better . has anybody else tried this ? . it is a 1985 johnson 120 horsepower . thanks .

 

[BoatBuoy]

Re: air silensore cover box

That's interesting. How many RPM did you pick up at WOT?

 

[canman]

Re: air silensore cover box

dont know . my tach is broke .

 

[HighTrim]

Re: air silensore cover box

You might want to test your rectifier. It converts the AC to DC to gauge your rpms

To test the rectifier.....

Place meter in Hi ohms position

1. Disconnect rectifier lead from terminal block. Connect one ohmmeter lead to either yellow or yellow grey rectifier lead, and other meter lead to ground. Note reading

2. Reverse leads, and note reading. Infinite or very high reading in both checks indicates diode open. zero reading in both checks indicates diode is shorted. Normal diode will show a reading in one direction and no reading in other.

3. Repeat with other rectifier yellow lead.

4. Repeat test, connect meter between rectifier yellow lead and rect red/purple lead. Between yellow/gray stripe rectifier lead and rect red/purple lead.

 

[F_R]

Re: air silensore cover box

Maybe it just sounds like it's going faster. Most motors actually lose power without the silencer because it is figured into the final fuel / air mixture.

 

[canman]

Re: air silensore cover box

thanks . iwill try that on the weekend . i work straight midnights .

 

[BoatBuoy]

Re: air silensore cover box

Maybe it just sounds like it's going faster. Most motors actually lose power without the silencer because it is figured into the final fuel / air mixture.

Yep, that's kinda where I was headed.

 

[canman]

Re: air silensore cover box

that is one thing i am trying , it still has that miss in it that i am trying to figure out .

 

[HighTrim]

Re: air silensore cover box

If you have a "miss", assuming the fuel system and carb are ok, it is usually spark plug related (under torqued, faulty or crossed leads, defective, incorrect), or ignition related (the timing could be off, loose wiring, damaged coils, arcing, loose connections, leads grounding out, or 1 of the PP, charge coil or sensor coil).

 

[canman]

Re: air silensore cover box

this motor had a new head put on it 2 years ago . it has been to two different mechanics , it has new plugs , new wires , four new coils , new gas filter , the timing checked , and compression in all cylinders is around 125 .plus all four carbs were redone . after all that they tell me it is an internal problem . i just dont agree with them .

 

[Walker]

Re: air silensore cover box

Shouldn't run a looper motor without the air box cover. You can lean it out and burn it up.

 

[canman]

Re: air silensore cover box

i took the air box cover off to see if that was part of my problem . this is the first johnson i have owned , i have always had mercs . i will figure this miss out yet .

 

[Dhadley]

Re: air silensore cover box

Be very careful with loopers if you remove the airbox cover. On a looper removing the cover leans out the carbs quite a bit. Not like the crossflow. If it runs better under a load with the cover off it may mean the motor is running rich with it on.

If it sounds like it's missing it may be running so rich it's blubbering. But that may be what saved the pistons while running it with the cover off. Put the cover back on and check timing under a load. Let us know what you find.

 

[canman]

Re: air silensore cover box

the mechanic told me he checked the timing under load and said it was ok .

 

[Dhadley]

Re: air silensore cover box

What did he set it at?

 

[canman]

Re: air silensore cover box

i am not sure what he set the timing at . i called his shop when i got up but he was gone .

 

[Dhadley]

Re: air silensore cover box

Don't accept an answer like "by the book" or "it's set correctly". We need a number. Look on the flywheel. If he really set the timing there's usually a mark on the number he was looking for.

 

[canman]

Re: air silensore cover box

i will look for that timing mark when i get home in the morning when i get home from work and get back to you . thanks .

 

[canman]

Re: air silensore cover box

i checked the timing marks just now . i have one mark at 20 and one mark at 4 .

 

[Dhadley]

Re: air silensore cover box

Yep, see? He set it wrong too. Check the manual for the wot timing for a 1985 V4 looper.