Mercury 1500 Ignition and Trim Problems

[K_Smith]

Hi,

I'm trying to get my Grandfather's old boat up and running after sitting in the garage for several years. It has a 150HP Mercury 1500 and I think it's a '75 (will check serial # tonight). It will crank but not start. Had fully charged battery, pumped primer till hard, had cold start lever up. and used choke button. Seems like power isn't getting to the coil. Should the coil get power when the key is on or when cranking? And is this likely to be a switchbox problem?

It also has a problem with the power trim. It will go down, but not up. It has the 3 button setup on the dash. When the top buttons are pushed for up and out it just makes a loud click. From the other posts I saw on here it could be a solenoid, relay, or low fluid. How do I check/fill the fluid?

Thanks! Can't wait to get it up and running again!

 

[Chris1956]

Re: Mercury 1500 Ignition and Trim Problems

OK first the trim. Push top and middle buttons at the same time. Motor should tilt up. if not suspect solenoid on trim pump is bad or wiring is bad.

That motor needs +12VDC on switchbox red and white wires (not the distributor white wire), in order to have ignition. Coil is pulsed when it is time to fire, so you will not see constant voltage like on points/coil ign.

Get on the CDIElectronics.com website and look up truoubleshooting procedure for battery powered- CDI-Distributor ignition for mercs.

Good luck with that baby. It is a screamer....

 

[Chris1956]

Re: Mercury 1500 Ignition and Trim Problems

Fluid fill on on upper right of trim pump. You will see unpainted round head slotted screw. Remove and stick cotton swab into resevoir. If it comes out clear red, use Dextron ATF. if brown use 5W-30 motor oil. Fill to overflow, motor Up(I think)

 

[K_Smith]

Re: Mercury 1500 Ignition and Trim Problems

Thanks so much! We finally got it running last night. We checked the red and white wire at the switchbox and they were good and we looked at most of the other wires, started checking for spark and it just started. We also worked on the power trim and it was the solenoid, was able to get it up once we bypassed it.

So.. we're going to replace the power trim solenoid, replace a couple wires that aren't looking so good, get new hydraulic hoses and change the fluid, change the lower unit fluid, get new spark plug wires, dist. cap and rotor..also read that we should replace the water pump or at least the impeller. Is there anything I'm missing that we should do after it has been sitting for this long?

 

[bktheking]

Re: Mercury 1500 Ignition and Trim Problems

One BIG thing you are missing, go through the carbs (replacement kits) if it's been sitting that long, plan on 3-4 hours to removing everthing to get at them, rebuilding and reinstalling. Then bank on another 1/2 hour to get the carbs dialed in on the trailer in the lake.


Do the impeller for sure, these inline's should have it replaced every year.

As far as cap and rotor, this isn't a ford mustang, that cap and rotor will cost you big $$$ if you can find them, you may want to inspect and keep what you have.

The rotor alone on ebay is at $231 USD

http://www.ebay.com.au/itm/393-4312...at_Parts_Accessories_Gear&hash=item3a65a36b43

The cap is about $140-150 if you can find one.

 

[Chris1956]

Re: Mercury 1500 Ignition and Trim Problems

Hold on to your hats. The dist cap for that motor is $100+, if you can find it. The rotor is non-replaceable. it is real fragile and if you break it it is a $200 part.

yes change the gear oil and rebuilld the waterpump. Replace the impeller, wearplate and the two gaskets. Pump up the grease fittings.

What BK said about the carbs is likely true. At least check them out. The old floats are made of foam, and can disolve. The newer ones are white hard plastic and can crack.

 

[K_Smith]

Re: Mercury 1500 Ignition and Trim Problems

Is there any reason I couldn't (or shouldn't) cross-reference the cap and rotor to Napa parts?

 

[Chris1956]

Re: Mercury 1500 Ignition and Trim Problems

Xref it if you can, however, I will doubt you will find any.

 

[bktheking]

Re: Mercury 1500 Ignition and Trim Problems

Good luck if you can, look at the rotor, it's not even close to a car rotor.