1983 Vking rebuild

[OnPad]

I have 2 lowers with bob's cones, one they did, one I did, no problems so far.
I do have a old preload case that has a land and sea, or something to that effect. Who ever installed it, used bondo, and it likes to crack on the seam. Also broke a couple of drive shafts on that one.

[LakeFever]

On a good note, mid 80’s out of a 150 is insane man. I couldnt crack 80 with a 2.5 200efi on mine so your speed is impressive as heck imo. Congrats

[VkingMike]

My assumption is the boat is quite a bit lighter after the coring. I'm sure the few mods to the 150 helped this too. The larger bore 200 carbs and going up a few main jet sizes really woke this thing up on the top end along with removing the super long exhaust tuner and replacing it for a shorty.

[OnPad]

I'm impressed!!!
What gear ratio are you running?
I have a 150 supermag on my ltv that I did a tuner, and opened the adapter plate up a little. Can't say I've ever hit 7k rpm, even with a 26p Yamaha drag. Actually I probably did when I snapped a driveshaft.

A little bit of alcohol, or acetone works good to smooth the surface of that PC-7.

[VkingMike]

Honestly not sure of the lower ratio lol

But we are back in business..

[rjdubiel]

Honestly not sure of the lower ratio lol

Mark the prop with a marker on the very top in the center, then turn the flywheel one turn. Look where the mark turned to and whala you will see 2:1 or 1.87:1.

if the lower is a 2:1 the mark will be 180 degrees turned, or it will go from the top to the bottom of the prop. If 1.87:1 it will be a little further around and past the 180 degree mark (straight down by the skeg like a 2:1 would be).

[VkingMike]

This is why I love this site, there is so much to learn. Thank you

[VkingMike]

I found a 40amp flexplate style flywheel, so I am going that route to avoid changing electronics to 16amp. I just cleaned it up, fresh paint and some new hardware. I've read they don't cool as well at higher RPM with less vents, but I do not do much sustained high rpm.

Real world weighing on 2 separate scales showed the same results. It's not a lot, but every little bit can help keep load off the upper bearing.

Cast Iron flywheel 12.6 lbs
Flexplate flywheel 10.4 lbs

[rjdubiel]

get a run going and keep it short, see how much you can get out of it. I think the issue with the 40 amp is people running miles and miles at 7K+. Just a 45 second run up to 8K I would guess is fine. if you spin that 28P to 8K you are at 95-100.

[rjdubiel]

I just cleaned it up, fresh paint and some new hardware

Can I send you my flywheels as they both need a cleanup! haha. Looks great!

[VkingMike]

Just got a GoPro a few weeks back and still learning how to use it.

Took some video last weekend out on the river.

https://youtu.be/C2eXZpejvTM

[LakeFever]

Where did you find the flywheel?

[VkingMike]

Where did you find the flywheel?

I found this one locally from a guy.

I struggled to find a 40amp online that would fit the right years.

[tnelsmn]

What GoPro do you have? If its a 5 black or newer you'll be able to overlay the speedometer on the video etc.

If you have a new enough one make sure the GPS is tuned on on the camera. Then download the free GoPro Quick software from them and you can add the speeds and whatnot with the software.

[VkingMike]

So why is it a good idea the verify timing after replacing a flywheel?

Removed the cast iron unit and got the flexpate style flywheel installed on Saturday. I purchased one of Jay's dial indicators and started on cylinder #1. I was surprised when 0 was dead on with the TDC pointer. I indexed all 6 cylinders and made marks for TDC and 25 degrees BTDC on each. I then connected my light and went for timing. I was previously about 22-23 degrees full advance, new flywheel had me at 17 degrees full advance and base in the negative numbers when idling. I set it to 23 again and checked all cylinders. All of them fell right at 22-23 except for Cyl #6 at 25 degrees.