16ft Glasspar w/65hp 2 stroke

[jimmbo]

If you use an Automotive tach on the Ignition, you would have to set it for 8 cylinders.

 

[RRafkin72]

If you use an Automotive tach on the Ignition, you would have to set it for 8 cylinders.

It is an Automotive Bosch set to 8cyl. I read on another thread that the thunderbolt/lightning energizer need a tach that has the switch for the number of poles of the Alternator and that the automotive ones arent for 2 stroke. I did get a chance to use the digital tach and confirm that it reads high. When my helm reads 1500 I'm actually at 1000. When my helm reads 2500 I'm actually at 1700. By this math When I read 6500 I'm assuming it was actually around 5000 which is pretty good... Hopefully....So I will be shopping for a outboard tach and getting that wired up soon.

Also kinda looking for a 2 blade prop just for research and development. Assuming a 3 blade 13.25 diameter × 17 pitch got me to 5000 rpm, would I need to go up or down in pitch/diameter to get similar performance with a 2 blade?

 

[jimmbo]

Depends on how the engine Wiring is. Some Wiring Diagrams show the Tach lead going to the Ignition System, others, even for the same HP, show it going to the Charging System.

Changing the # of blade has no hard and fast rules regarding pitch adjustment. The 2 Blade Props Mercury used to make, usually had more Diameter, and a Larger Blade Area, as well as a different Rake Profile. It was rare that the same Pitch was used when switching from one to the other. Usually a slight increase in Pitch when going from 3 to 2, as the 2 blade usually will result in more top speed, dud to less drag.

 

[RRafkin72]

Just picked up a Sierra Amega 7K tach from West marine and wired it up per the instructions came with a chart about all outboards and how many poles each alternator has, super easy. I now have a working tach that may need slight calibration once I compare it to my phototach, but maybe not. Coincidently right out of the box it was set to the correct number of poles which was 6 for me.
Thanks again for all the guidance guys, I am planning on going out this weekend to log some more numbers!

Until then I'm trying to settle a bit of a surgy idle. Carbs are recently rebuilt by me. Ran a splash of sea foam in the last tank during sea trial. This weekend I plan on setting the idle mixture screws to their happy medium as for now they are both 1.5 turns out. Could the carb linkage be off slightly and holding one butterfly open more? Also I have a tiny (very very small) fuel weep at the twist lock fitting at the engine not sure if these motors are that sensitive to losing fuel prime? Before I got this motor running I had compression tested and got something like 120 on the top 3 and something like 105 or 110 on the bottom cylinder. The only things that are not new or rebuilt in the fuel system is the half of the twist lock fitting that is on the motor under the coil, and the diaphragm pumps.

 

[jimmbo]

When you put the Carbs back on did you do a Link and Sync? Are both carbs fully closed at Idle, they are supposed to be, and they are supposed to remain closed until the timing advances to a certain Value(varies with engine model). Do you have the Proper OEM Service Manual?

 

[Scott Danforth]

FWIW

Automotive aftermarket tachs have selector switches for 4,6, or 8 cylinders. Generally 3-4 settings. Most do not work with outboards

Marine tachs have more settings for the alternator/switchbox outputs in addition to the cylinder setting. Generally 6+ settings to work with outboards, Inboards, diesels, etc

Industrial tachs go off flywheel teeth pulses and usually have a 10 dip switch input and a chart to set teeth pulses and alternator pulses

 

[RRafkin72]

When you put the Carbs back on did you do a Link and Sync? Are both carbs fully closed at Idle, they are supposed to be, and they are supposed to remain closed until the timing advances to a certain Value(varies with engine model). Do you have the Proper OEM Service Manual?

Not properly. I have a manual but it's not OEM it's a glens outboard for most mercury models. What is the correct procedure to link and sync?

 

[RRafkin72]

Well I got the carb linkages evened out and adjusted idle and my primary and secondary pickups again. Definitely seems to start and run smoother.

I went out Sunday for another sea trial to check what rpms I'm making. Had the trim pin set a bit higher than last time, ended up seeing about 4300 on my first full throttle run. I think before swapping props I can squeeze a little bit more out of my full throttle adjustments and get it closer to 5k.

Unfortunately, During that first full throttle run. I came across a bit of wake from another boat which bounced me and pitched the boat bow down and over to the the port pretty hard. I throttled down as quick as I could but I won't lie it was kinda violent. After this I picked a new heading to avoid wake, adjusted the trim pin a little lower and tried again but the boat wouldn't get on plane and I was stuck at 3000 rpms. Convinced there was an engine issue I motored back to the dock to find the motor was fine but I was indeed taking on water. So we made way back to the ramp and pull it out and found that the transom had cracked a good 6 inch crack along the bottom corner where it meets the bottom of the hull.... not the most relaxing day boating

 

[Willyclay]

Wow, sorry to see that damage but be thankful that neither you nor any others got hurt. Come back and let us know how you plan to proceed. The members here are great and can answer all of your questions. Good luck!

 

[jimmbo]

Likely a rotted Transom. Fractured right at the area where the Glass had been penetrated by screws. That area was likely also stressed by not being supported properly on the Trailer, as shown in the pic.
It is a 63 yr old boat, and to be honest, not having rotted Stringers/Transom would be a "Stop the Presses" event. Heck, I'm a couple months older, and I am Rotten to the Core
Glad you made it back to the Ramp

 

[Scott Danforth]

looks like a stringer and transom job is needed.

 

[RRafkin72]

I thought the same thing about the point of entry for water intrusion being the screws but didn't consider how it rode on the trailer adding stress, will now be taking a look at that too.

My plan with this has always been to take it all the way down to the stringers, I just wasn't hoping so soon... but here I am.

I'm thinking to take the top cap off. Replace the stringers, floor, the transom and reinforce the bow deck. All glassed in sealed marine wood or cousa. Install bilge pumps, float switches and alarms. Re do any drain tubes if necessary. Install a transducer, and underwater lights (not critical but while I'm there...) Address the potential trailer issues. And then make the top side sexy, paint/gel coat, upholstery, lighting/sound etc...

 

[jimmbo]

That Roller, should have been under the Transom, not forward of it. Hooks can develop from that.
Unless that boat has some kind of Sentimental Value, you will be money ahead to find another Boat, because it can become a Time and Money Pit of a Restoration

 

[Scott Danforth]

Just materials to do the restoration will exceed $1000.... Probably closer to $1500. Incidentals will be about $300, PPE will be about $200

 

[RRafkin72]

So I am a marine diesel mechanic for a living the shop I work at has lots of things that will help me keep costs down tools supplies etc plus we have a really good fiberglass/finish guy. The boat is just another project for me, and if I bought another one I'd probably still go down the same road honestly. Unless I find something I really like that would be an easy swap for the mercury that is also in good condition for a killer deal.... then maybe

What intimidates me the most is getting the cap off because the seating which is part of the cap connects to the floor