1972 Starcraft Nova 18'

[captainnate]

Re: 1972 Starcraft Nova 18'

Ok, so I did a compression test today. It was my first ever, so hopefully I did it correctly. I rented the tool from the auto parts store. These are the numbers I got:

#1 - 122
#2 - 126
#3 - 0
#4 - 0

I checked twice on 3 and 4, and then did 1 again to see if I screwed up, but got the same numbers. Also, the 1 and 2 had very black (like coal) spark plugs. 3 and 4 had very wet, but otherwise clean plugs. The engine actually idles now, but very rough at times. It causes quite a bit of vibration. I took a picture of the black spark plug, but I'm guessing most of you know what that looks like. So, I don't know what to think now, obviously I have some problems. Thanks in advance for any advice.

 

[jasoutside]

Re: 1972 Starcraft Nova 18'

It's time to hunt down that donor boat with a nice 4.3 V6 in it. Actually prime time, buyers market

 

[captainnate]

Re: 1972 Starcraft Nova 18'

What are some of the likely reasons for those zero compression readings?

 

[proshadetree]

Re: 1972 Starcraft Nova 18'

Blown head gasket, cracked head, valve issues, bad ring or busted pistons. With those numbers I would suspect a blown head gasket between 3 and 4. Were all the plugs out when this test was preformed?

 

[captainnate]

Re: 1972 Starcraft Nova 18'

No, all the plugs were not out. I did one at a time, I guess that is one thing I did wrong. I took one plug out, (left the others in), and tested that cylinder and then put it back in, and took the next plug out, etc.

 

[proshadetree]

Re: 1972 Starcraft Nova 18'

First two readings are ok for an older engine. The last two are the ones to worry about. Pull the valve cover and check pushrods. Are they bent or off? If no then rip the head and look for cracks. If you dont see any check gasket for a blown spot between the cylinders. For insurance you can have the head worked. All it will cost you if dont is labor, oil and gasket set. This could be done in an afternoon.

 

[captainnate]

Re: 1972 Starcraft Nova 18'

Thanks proshadetree, I will try what you suggested. So if the pushrods bent, or off, I would just replace those?

 

[proshadetree]

Re: 1972 Starcraft Nova 18'

If push rods are bent or off try to cycle the valves and spray stems with penetrating oil. I put money on the head gasket though.

 

[captainnate]

Re: 1972 Starcraft Nova 18'

So right now only half of the engine is working, that would probably account for the vibration. There is also a noticeable sound, which to my untrained hear almost sounds like a spray paint can being shaken. Would the fact that only half the engine is firing account for the black plugs? Or is that a separate issue?

 

[captainnate]

Re: 1972 Starcraft Nova 18'

So I took the valve cover off, and definitely found some more clues. I don't know which is the exhaust vs intake, but the same ones where off/loose on number 3 and 4 cylinders. The rod was bent, and the end was smashed a little on 4. The rocker was totally off on number 3, but rod appears straight. Did the valves get rusted in one position, is that why this might have happened? I also noticed some almost foamy looking light colored residue on the inside of the valve cover; does that mean anything?
View attachment 116835View attachment 116837View attachment 116840View attachment 116841

I tried to put a pic of the rockers on here, but the files was too large, I'll see if I can figure it out and repost.

 

[jasoutside]

Re: 1972 Starcraft Nova 18'

Hey, when you get those photos working, post up over here...

http://forums.iboats.com/forumdisplay.php?f=21

Those guys are way sharp and can tell you right off what you are dealing with.

 

[captainnate]

Re: 1972 Starcraft Nova 18'

Thanks man, I will post at both places.

View attachment 116842View attachment 116843

 

[captainnate]

Re: 1972 Starcraft Nova 18'

I had a bit of top end overhaul done on the motor. Now she runs pretty good. I am happy that it appears I have a good engine. I think my next step is to get the transom wood replace. It seems like a big job, but at least there is a lot of info here on iboats.

1972 mercruiser 120 - YouTube

 

[captainnate]

Re: 1972 Starcraft Nova 18'

I took the boat out for the first time I have owned it (1.5 years). It was a rough experience. Here is my list of problems: engine got very hot (impellar?), roller trailer is a pain (snapped hook off winch strap), seems to idle too high, shifts ruff. That's all not to mention the transom it still needs, and probably the floor, and a rewire of everything minus the engine. I don't know if I have the patience most of you guys have. Maybe I'll just sell it on craigslist.

 

[jasoutside]

Re: 1972 Starcraft Nova 18'

The joys of an IO and the love for a total boat rebuild - anything short of that and this ol Nova will beat you down buddy.

 

[Grandad]

Re: 1972 Starcraft Nova 18'

I took the boat out for the first time I have owned it (1.5 years). It was a rough experience. Here is my list of problems: engine got very hot (impellar?), roller trailer is a pain (snapped hook off winch strap), seems to idle too high, shifts ruff. That's all not to mention the transom it still needs, and probably the floor, and a rewire of everything minus the engine. I don't know if I have the patience most of you guys have. Maybe I'll just sell it on craigslist.

Hey Nate, you've gotta look at every one of those problems as an individual challenge. When you fix something, give yourself a pat on the back and feel some satisfaction in a job well done and move onto the next challenge. If you don't care about something, you can discard it easily, but I think you lose a feel-good opportunity. As has been said many times, when you sell, you probably won't get out of a boat rebuild the money that you put into it, but if you're going to use the boat yourself, you do get your money's worth. All us DIY's get a little discouraged once in a while, but you've got a nice model there that'll make you proud when you're done. - Grandad

 

[captainnate]

Re: 1972 Starcraft Nova 18'

Hey Grandad,

Thanks for the encouragement. I have a lot to learn about these boats. I'd love to just nail it, and do everything right the first time, but it usually doesn't happen that way. I guess patience is probably the main ingredient for these projects, followed by some time, and hard work. Grouping all the problems and hurdles together does make for a very intimidating situation. I need to chip away at one thing at a time. Maybe I'll take a day or two off, and go from there. Thanks again.

Nate

 

[captainnate]

Re: 1972 Starcraft Nova 18'

thanks for the words Jason, if I do follow all the way through I should get a very good education out of the experience

 

[jbcurt00]

Re: 1972 Starcraft Nova 18'

I guess patience is probably the main ingredient for these projects, followed by some time, and hard work. Grouping all the problems and hurdles together does make for a very intimidating situation. I need to chip away at one thing at a time. Maybe I'll take a day or two off, and go from there. Thanks again
Nate

And be forgiving when you miss a target deadline..... They will be missed... We all miss them

See Jas' Islander thread* Sometimes missing a date gives you time to reconsider how you plan to tackle the next challenge. And work thru how to actually go about getting that next task done. So when you get on to that next thing, it may go quicker (easier/better?) having had more time to plan the attack.

So for now, grab a hot cup of GluVit, sit back, relax, and give yourself a break:

And don't forget, sitting & staring at the boat in the garage counts towards resto work....

Besides, it's about boat building & boating, it's supposed to be fun :facepalm:

Very nice looking SC Nova BTW

* I absolutely have no doubt that Jas' Islander will be done, and done well

And beware the Michigan strain of MBS, Jas is patient zero

Multiple
Boat
Syndrom

 

[captainnate]

Re: 1972 Starcraft Nova 18'

Thanks jbcurt00, I know about MBS. I have two boats now, and the wife recently denied a third boat purchase. I don't think she understands the illness.