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cjhacker
06-29-2010, 01:03 AM
several months ago i was out on the lake, when all of a sudden my 82 mastercraft stars and stripes started running extremely rough on our first lap around the lake, shaking the boat pretty well, with an extreme loss of power. it eventually wouldnt start up anymore and we had to get towed in. every time since we have started it up, it still runs rough.
my dad and i have been troubleshooting to see if we can find the problem over the last couple months, but nothing yet. we have tried replacing the plugs, elec. ignition, distributor, heads (probably needed them resurfaced anyways at this point), and a few other things as well but with no avail.
the boat has a 351w in it with a littlle over 500 hours on it, with an upgraded breakerless electronic ignition, but have never experienced any problems of this magnitude before, especially not being able to find the problem.
we are waiting for a new voltage regulator to see if that may be the problem as well, but in general, im running out of ideas as to what might be the problem. the only other things i can think of if the new volt. regulator doesn't work is maybe it was bad fuel?, or something with the carb. possibly?
any one have any ideas or suggestions on what it might be? anything would be greatly appreciated, thanks!

Skipper
06-30-2010, 08:24 PM
Start with a compression test. All cylinders should be within 10 lbs or so. That will answer the question about your heads and the general condition of the motor itself. Then do a good rebuild on the carb. Get a spark tester to see if you are getting spark to the cylinders. If so, probably not an electrical problem.

Napagary
06-30-2010, 11:05 PM
Do you have the small Fram canister filter after the tank but before the fuel pump? I'd check for water in the fuel at that location. If you have a timing light, you can hook it up to #1, get it running (assume you can run it at home?) if there's a light, you have spark, etc.

oldairboater
07-01-2010, 07:29 AM
Has to have fuel, ignition and timing, compression and exhaust. Pull a sample--look at your fuel. Check your compression. Check your ignition. Check your timing. Look at your spark plugs---engine running lean or rich? Carbon or oil deposits on the plugs? Eliminate each possible problem. You should have started with the plugs. How did each plug look? Since the plugs are out --check compression on each cylinder. You can roughly check timing with a timing light with the plugs out. Also check ignition since the plugs are out of the cylinders. Each plug should have a good blue arc. Don't change out parts unless they are bad---trouble shooting by parts replacement can get expensive and cause more problems.

ski_king
07-01-2010, 08:05 AM
You mntioned that you replaced the distributor. I assume you replaced the distributor cap also, right?

The few times my 82 started running rough were most commenly a cracked distributor cap.

russfortin
07-08-2010, 03:09 PM
check to see if you have a stuck float in the carb. mine did the same thing last night. shaking pretty bad and has to start it in nuetral with the throttle wide open to get it to fire. i had fuel pouring out the rear j-vent tube becuase my float was stuck. give it a tap if you notice that same thing. just an idea...

cjhacker
07-10-2010, 01:29 PM
thank you all very much for the ideas, and sorry it took me awhile to get back on this thing.
havent been able to do much work on the boat lately as work has been demanding.

in the next week i will try some of these suggestions and let you all know what happens. thank you all again, very much appreciated!

does anyone also know where you can purchase new decal kits for an 82 mastercraft?
the mastercraft logo on both sides is peeling, as well as some of the stars running down the side of the boat. thanks!!

OldGlory
07-12-2010, 02:30 PM
Fuel was my problem...bought my 82 S&S in May of this year. It stayed on a private lake with boat houses. Problem was the seller told me that he "topped off" the fuel from 1/4 tank to full to mix last years "old gas" with new to make okay gas. I did the test drive and it was fine with a little hick-up with starting it. It ran fine for the first three times out (2-3 hours each time). On the fourth time same thing happened to me as you, except we eventually (starter fluid) got it started and ran low rmps all the way back to the ramp. Long story short...I drained the remaining fuel out (4 gal.) and rebuilt/cleaned the carb, filled with premium (95 octane) and has run like a bandit every since (40+ hours and two tanks worth)....

Hope this helps...

ski_king
07-12-2010, 03:12 PM
.....does anyone also know where you can purchase new decal kits for an 82 mastercraft?
the mastercraft logo on both sides is peeling, as well as some of the stars running down the side of the boat. thanks!!
Jim@BAWS helped me ouiut with some stars, I understand he has some full decal sets also. There are also some available on Ebay, but the quality is questionable.

I do have 2 side decals in beige, that I bougth to make a pattern from. They are available for the right price.


.......and has run like a bandit every since (40+ hours and two tanks worth)....
Are you saying that you get 20 hours per tank??