E100WTLCRS 84 100hp tach dropping out during throttle up

edfishing2

Petty Officer 2nd Class
Joined
Mar 6, 2011
Messages
144
About to my wits end.

Just got back from lake to try my latest repair(new coil). Spark gap tester now showed(haven't checked again since I got home) good 7/16 spark on all cylinders. During throttle up (attempt to plane off) the tach is dropping out and as soon as I pull back on throttle the tach starts working again. Also max rpm is like 3k. Can the rectifier cause the WOT to drop?

Two new powerpacks, 4 new coils, new plug wires/boots, new plugs already installed. All new carb kits, all new jets, new hoses, new thermostats, new fuel lines, new fuel pump.

Other new parts on hand(not installed yet), stator, trigger, rectifier/regulator.
 

SparkieBoat

Captain
Joined
Aug 17, 2009
Messages
3,643
Re: E100WTLCRS 84 100hp tach dropping out during throttle up

you need to get a DVA adapter. link is in my sig below, so is a free trouble shooting guide from CDI. rectifier can cause tach issues, also can cause damage to power packs/stator. you need to test it. and stator
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: E100WTLCRS 84 100hp tach dropping out during throttle up

Do you have an OEM Factory Service manual ? All the specs and procedures are in there.
 

edfishing2

Petty Officer 2nd Class
Joined
Mar 6, 2011
Messages
144
Re: E100WTLCRS 84 100hp tach dropping out during throttle up

Yes I have service manual and DVA adapter. I was just curious if anyone has seen a rectifier/regulator cause rpm to drop?
 

SparkieBoat

Captain
Joined
Aug 17, 2009
Messages
3,643
Re: E100WTLCRS 84 100hp tach dropping out during throttle up

yes, rectifier/regulator will cause tach problems, along with damaging other electronics..test it.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: E100WTLCRS 84 100hp tach dropping out during throttle up

A rectifier that is going bad will usually affect the tach-a good visual sign that there is a problem with it. When the rectifier/regulator starts to go, it can affect the tach in a number of odd ways. Including the problem you are experiencing. If your engine does not have power trim, you will have a rectifier only. If it has power trim, the engine will have the more expensive combination rectifier/regulator which sits in the top of the powerhead under the flywheel.
 
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edfishing2

Petty Officer 2nd Class
Joined
Mar 6, 2011
Messages
144
Re: E100WTLCRS 84 100hp tach dropping out during throttle up

it does have the power tilt and trim. Strange that as soon as I push throttle forward the tach drops and the motor rpm bog.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: E100WTLCRS 84 100hp tach dropping out during throttle up

I had a tach which would always go to zero after 3000 rpm's. New rectifier cured the problem.
 
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