Starts dies blows fuse on take off

[Rongenco1]

• #1

When I start my 305 mercruizer it runs fine with cups on in the driveway, but when I put it in the water it starts but when I'm just about to plane out it dies(fuses blown). Same color wire goes into this part could it be a this, or control model heating up as it is mounted the the side of exaust.manifold.

 

[Bt Doctur]

Do not recognize the item in the second pic can you take a pic from farther out

 

[Rongenco1]

It is at the front of the intake manifold 2 wires coming out. Close to the main belt.

 

[alldodge]

What is the motor serial number?

 

[Rongenco1]

Jtc66823h607

 

[alldodge]

That's not a Merc number. Look above the starter for a plate. It would be a number, letter, and 6 more numbers 0W123456

I think you have a TKS carb and the fuse blowing would be 20 amp. The temp switch is seen in the pic, and is probably shorted. It might even have blown the ignition fuse (20 amp at helm) but your not noticing because the temp fuse is back feeding the ignition if the diode is shorted

 

[Rongenco1]

That's not a Merc number. Look above the starter for a plate. It would be a number, letter, and 6 more numbers 0W123456

I think you have a TKS carb and the fuse blowing would be 20 amp. The temp switch is seen in the pic, and is probably shorted. It might even have blown the ignition fuse (20 amp at helm) but your not noticing because the temp fuse is back feeding the ignition if the diode is shorted

View attachment 349322

Thanks engine #Ow650604

 

[alldodge]

Thanks
Yes TKS carb, check the ignition fuse feeding the red/purple on the key switch

 

[Rongenco1]

That one is OK it blows 15 behind intake or the 20 above intake manifold, same color wire going into temp switch

 

[Rongenco1]

These two

 

[alldodge]

I'm missing something
The 20 amp I understand, the 15 amp I don't

The ignition fuse is behind the dash (helm) or in the fuse box/panel

 

[alldodge]

The one fuse might actually be the diode which was replaced with a fuse

 

[alldodge]

TKS

 

[Rongenco1]

I ordered this diode also, took out the ignition switch, fuse there is fine. Ordered a temp switch also. I will install those parts and go from there I guess. Almost ordered a ignition.

 

[alldodge]

Take a ohm meter and measure the contact. Place probes on one way then swap them and note the difference. One way will read low resistance, the other way will read high. If it reads the same ion both directions then its shorted

 

[alldodge]

Should be able to place ohm meter on the temp switch leads one at a time and measure to ground. Neither should read to ground

 

[Rongenco1]

Will do. What is this mangled looking part hiding under the front of the carburetor

 

[alldodge]

That looks like the idle adjusting screw. It had a cap over it at one time once adjusted at the factory. The PO tore through it

 

[Rongenco1]

Thanks for all of your help! We will see how it goes this week.

 

[Rongenco1]

Replaced the diode and the thermo switch running well today