2000 Johnson 60 HP

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wili

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Apr 5, 2002
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The carburetors were swapped with 70Hp carbs after purchase in 2000.
Outboard bogs down at wot. Will only get about 4200 rpm. I have been chasing this for about one year. Have replaced fuel lines from tank to motor, gas tank has been swapped, squeeze build and water separator filter changed, carbs have been cleaned by two different mechanics. Stator was replaced had no affect, compression test came back good. Still cannot find the issue. I have ran at WOT and sprayed premix into carbs and only bogged a little. The mechanic is unsure what could be causing this issue. Stated maybe the exhaust is clogged.

Anything come to mind on where to go?
 
flyingscott

flyingscott

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Did you put the correct Jets in it? The correct yr Carbs? All 70 carbs aren't the same. Wrong Gasket on top if it's plastic top? or is it a metal carb? Primer leaking?
 
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wili

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The motor ran fine for 20 years so I would say the proper carbs/jets were put in it. No leaks on primer.
 
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wili

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No the carbs were changed by the boat dealer back in 2000 before it was sold the first time. It was then traded in on a new boat which is when I purchased in 2006. I have ran this motor since and have been chasing this issue for the past year. This used to be intermittent which if I shut the motor off and restarted it would run good for a while. Sometimes the rest of the day other times a few minutes. Now this issue is constant. So for over 15 years (for me) this motor ran great with the 70 hp carbs
 
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Crosbyman

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OK so compression is ok...what is left just fuel or electrical issue.
If the issue is constant..... light is at the end of the tunnel...

I will look for the wire diagram but in the meantime...


easy stuff first.. me I would look at electricals first starting with ignition KEY on power interruptions or power pack kill control wiring . A Chat GPT wiring diag. shows these engines may run without Key ON b+ as long as the pwr pack kill cct is not active (grounded). Inspect all wiring & connections for chaffing or oxydation!

Your power pack may be overheating or has become more heat sensitive. If you can cool it with a spray can ( inverted keyboard spray can from the dollar store is COLD ! ) or keep it away from engine heat it may stabilize.

An IR gun may point to an overheating component

Fuel wise looks like a VRO engine... could you bypass it and run fuel mix for a while to see what happens. hand pump the fuel in the carbs during a trial run to see if things work properly.

has the VRO fuel pump ever been checked out or serviced (see utubes)

make certain carbs are venting properly.

BTW does it die like sudden instant death (electrical) or is it slow dying like from lack of fuel ??
 
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wili

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The motor does not die. It will run at WOT but only at 3600-4200 rpm
Also vro was bypassed when I purchased. I have replaced VRO fuel pump with regular fuel pump while chasing this issue, it changed nothing this was during it being intermittent.
 
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wili

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DVA test- would it idle fine with power pack issues? Tops are good. Running pre mix with a regular fuel pump.
 
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Crosbyman

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when it " only runs" at 4200 if you spray fuel in the carbs one after the other does the engine pick up rpms or fuel spray has no effect .?

have you checked the exhaust passages has suggested. Tried a good decarb product like Merc POWER TUNE or similar Evinrude fuel system cleaner ... hey some folks even use a heavy SEAFOAM fix.
 
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saltchuckmatt

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wili said:
No the carbs were changed by the boat dealer back in 2000 before it was sold the first time. It was then traded in on a new boat which is when I purchased in 2006. I have ran this motor since and have been chasing this issue for the past year. This used to be intermittent which if I shut the motor off and restarted it would run good for a while. Sometimes the rest of the day other times a few minutes. Now this issue is constant. So for over 15 years (for me) this motor ran great with the 70 hp carbs
Click to expand...
You say "good compression" may I ask what those number are? And did anyone do a spark jump test?

Sounds fuel related but you never know.
 
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wili

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47
Crosbyman said:
when it " only runs" at 4200 if you spray fuel in the carbs one after the other does the engine pick up rpms or fuel spray has no effect .?

have you checked the exhaust passages has suggested. Tried a good decarb product like Merc POWER TUNE or similar Evinrude fuel system cleaner ... hey some folks even use a heavy SEAFOAM fix.
Click to expand...
Spraying fuel directly into the carbs had little effect, it would bog the motor slightly.

I have ran a treatment of seafoam but nothing else
 
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racerone

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Dec 28, 2013
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Information must be posted.------What pitch prop?---What boat?----Does spark jump a gap of 3/8" on each lead?----Actual compression values.----Does timer base rotate fully?----Flywheel key checked?----Run with timing light ( one cylinder at a time ) to see if there is a spark issue.-----Shine a strong flashlight into each carburetor to compare fuel flow up the nozzle.-----Reed valves checked?
 
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