TOPIC: 135 hp restoration

So my mom is storing her early 70's Cee Bee Avenger 18 foot boat at my house, since I bought a house on the river. It has been sitting covered under a carport since the early 80's. I took the cover off the engine to do a compression test to find the spark plugs are missing. So I sprayed some 2 stroke fogger oil in the carbs and plug holes and did a compression test. The top 5 cylinders are all above 120 psi, the bottom one is so close to the cover that I cannot easily get compression tester started in spark plug hole and didn't want to cross thread it so I didn't test the bottom cylinder.

The serial number of the engine is: 2940947 according to the label on the engine mount just below the power head.

I can tell I will need a new interior cowl engine harness, from inspection most of the insulation is coming off the wires. Carbs probably need to be gone through as well as fuel pump and hoses. Lower unit needs to come off to check water pump and gear oil.

I used a spare jetski battery and some jumper cables to perform compression test. Not sure where to start buying parts or what to rebuild first. Knowing my dad the engine would not stay running on the lake the last time it went out, and he brought it home and parked it. He threw gas tank out as it sat for so long with bad gas in it it was rusted through.

I see old mercs sells engine harnesses, should I start with one of these, carb rebuild kits, or something else?

I would see if it has spark. if it does see if it runs and go from there.
Just Me.

You're on the right track with your planned list of maint & repairs.

To do a quick-'n-dirty spark check, pull the plugs, stick 'em back in their boots, lay the plugs on a good ground.

Apply +12VDC to the Red and White terminals of the switchbox (Starboard side).

Rope over the engine, you'll get spark even at "roping speed" if the ign is good.

If no spark, pull out the coil wire at the coil; unscrew it from the distributor; plug the coil wire back into the coil and lay the free end approx 1/2" from a good ground. Rope over the engine and see if you get spark then. If you do, the rotor has issues or the distributor cap.

If no spark still, disconnect the 3 distributor wires on the Port side of the switchbox. On the same side of the switchbox, jumper together the Brown and White terminals.

With power applied to the switchbox (Red and White, Stbd side), ground the black terminal of the switchbox (port side).

Every time you ground the black terminal you should get a spark. If no spark, check your wiring for integrity but probably the switchbox is bad.

If you do get spark, it means both switchbox and coil are good and the distributor trigger is bad. This requires complete disassembly of the distributor and replacement of the distributor body, which is integral to the trigger. CDI Electronics makes a replacement but it ain't cheap!

I bought a stubby compression gauge from johnsmcintoshvintagemercuryoutboard.com/ that fits down in that bottom cylinder. Pretty slick and no cross threading. Not sure if he has more. I believe he is in Hayward, Wisconsin.

wow, um, lots of info there, I'll have to print it out and take it out to my carport that the boat is under and get to checking! I guess first I should get some spark plugs. I personally like NGK plugs, but know very little about these motors, any plug recommendations?

to test us any plug and open the gap to 1/4 in.

Hello,
It made me smile to read of the Cee Bee Avenger, as my family was a dealer for 30+ years. We have both a 16 foot and 16 foot, 7 inch The Avenger models ourselves. As to the compression and ignition testing, I would suggest that the internal engine wiring harness's red and white leads should be disconnected, and you should provide jumper wires directly from the battery (+) terminal directly to the red and white studs on the switchbox (ignition module) with the (very) rotten wiring pictured. Yes, one does need to know compression and ignition, but taking the risk to "blow" costly components when doing so should be avoided. Similarly, the two yellow AC voltage input wires to the (battery charging) rectifier should also be disconnected first, as the rectifier will very likely "blow" otherwise. The compact compression gauge mentioned is available if desired, but reasonable care when installing a compression tester which features a rubber hose can be utilized. Finally, we would be happy to quote parts, as we sold Merc 1350 models when new, and we were a Mercury dealership for 50+ years.

Good Luck,
Joe
www.fergusonpoolemarine.com
This email address is being protected from spambots. You need JavaScript enabled to view it.

wow! thats a really nice boat! If I can get the motor restored and the hull checks out, I foresee us needing a towing pole like you have. My mom used to water ski behind the boat, but it has no towing tower, they must have used a rope with a V or something?

The only really obvious rotten place my inexperienced eyes see is the battery box mounting area. Even though some of the fiber glass in the floor is thin and obviously permeable, when poking it with a screwdriver it seems solid. Of course it hasn't been in the water in 30 some years, and only sometimes got wet from the rain. The upholstery is shot, as is the gold metal flake paint. The engine controls and steering will probably need as much work as the engine wiring harness...

My mom asked me to see if I could get it to run before she dies, but then shes only like 72... Hopefully I'll have some time to work on it this week and report back! Is there any easy way to get fuel to the carbs if the gas tank and lines are missing?

The NGK spark plug for the 1350 is NGK BUHW.
The 1350 is a BEAST, and one of my favorites.
doc

Ferguson_Poole wrote: Hello,
It made me smile to read of the Cee Bee Avenger, as my family was a dealer for 30+ years. We have both a 16 foot and 16 foot, 7 inch The Avenger models ourselves. As to the compression and ignition testing, I would suggest that the internal engine wiring harness's red and white leads should be disconnected, and you should provide jumper wires directly from the battery (+) terminal directly to the red and white studs on the switchbox (ignition module) with the (very) rotten wiring pictured. Yes, one does need to know compression and ignition, but taking the risk to "blow" costly components when doing so should be avoided. Similarly, the two yellow AC voltage input wires to the (battery charging) rectifier should also be disconnected first, as the rectifier will very likely "blow" otherwise. The compact compression gauge mentioned is available if desired, but reasonable care when installing a compression tester which features a rubber hose can be utilized. Finally, we would be happy to quote parts, as we sold Merc 1350 models when new, and we were a Mercury dealership for 50+ years.

Good Luck,
Joe
www.fergusonpoolemarine.com
This email address is being protected from spambots. You need JavaScript enabled to view it.

Is it possible you could post pictures of where to disconnect wires?

Hello,

Might you be willing to e-mail me directly (This email address is being protected from spambots. You need JavaScript enabled to view it.) and then possibly we can talk by phone, or I may be able to find a helpful picture(s).

Regards,
Joe

Trying to replace the engine harness. The new harness has less wires, are jumpers needed to connect the colored pads that match colors? Wrong harness?

My picture is too big on my phone. I’ll have to upload it from the computer when I go inside.

I dunno why I didn’t think of this before. I checked my spare motor and it had an updated harness like I’m installing. Very clear what goes where.