1979 45 hp chrysler prop stops turning under load

[btpaints]

I recently bought a 14 foot fibreglass powerboat, the price was right, it looked pretty clean, the guy hooked water up to it and showed me it working, it started great and idles nice, however I noticed that the prop wasn't fully spinning, since I wasn't on the controls I didn't think much of it, brought it home cleaned it up. Took it out on the lake the next day and fired it up and the engine would rev but the boat would not go anywhere, much like an old Chrysler mini van the missus used to have it did manage to "slip" into reverse for a few minutes but that was it. So I fired up the electric trolling motor and brought it back in. I have done extensive searching online and have come up with a couple suggestions of checking the shear pin and the splines on the prop, both are fine, and checking the shift linkage which seems a bit off however I can put it in neutral and spin the prop both ways as well as forward and reverse and only be able to spin the prop one way and have resistance the other. The major problem is that in small town prairie Alberta there are zero boat mechanics to ask for advice or help, I am mechanically apt and more than capable, I just need to know where to start or of this is common and some suggestions to get this thing back in the water so the kids and I can enjoy it as intended. Thanks in advance.

 

[jerryjerry05]

Re: 1979 45 hp chrysler prop stops turning under load

Inside the prop is a rubber hub.It's probbly given out and needs to be re-hubbed or a new prop.
Probably easier to buy a new one.
Take it to a boat dealer they maybe can get it fixed for you??

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

So this is in between the actual propeller and the metal hub that goes over the shaft? Sorry I looked at it and it looked all metal, but if it was to be sacrificial for the sake of saving the motor it completely makes sense.

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

Ok, I pulled the prop and based on another thread I was reading I marked the back and the front of the prop with nail polish so I could see if it was spun, I cranked it up shut it down took it off and it hadn't moved at all. So this brings me to the conclusion that I need to move up the leg with this problem, I should mention that I did have reverse on this test, any help is greatly appreciated.

 

[pnwboat]

Re: 1979 45 hp chrysler prop stops turning under load

Try draining the gear case oil and look for small metal flakes/pieces mixed in with the oil. If there are any pieces of metal, then yes, there is a good possibility that the problem is in the gear case itself.

 

[jerryjerry05]

Re: 1979 45 hp chrysler prop stops turning under load

Yes very possible there's something else.
Try unhooking the cables.Shift by hand?

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

I drained the oil out of the lower unit and although it was extremely milky there was no chunks of metal or any visible filings. I am going to let it drain over night before I fill it up again. I had read previously about it being a shift linkage issue and i tried playing with it, but lack of an actual procedure prevented me from getting anywhere with it. I had never thought about disconnecting cables and hand shifting, I will give that a try tomorrow. Thanks for the suggestions any other suggestions I am all ears.

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

I drained the oil out of the lower unit and although it was extremely milky there was no chunks of metal or any visible filings. I am going to let it drain over night before I fill it up again. I had read previously about it being a shift linkage issue and i tried playing with it, but lack of an actual procedure prevented me from getting anywhere with it. I had never thought about disconnecting cables and hand shifting, I will give that a try tomorrow. Thanks for the suggestions any other suggestions I am all ears.

 

[jerryjerry05]

Re: 1979 45 hp chrysler prop stops turning under load

If you have any water in there??? You need to pressure test it to find the leak.
Also change the washers on the screws.That's where I've found the most leaks.
Merc part#12-20260@12-19183 Sierra part# 18-2945

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

Okay so I pulled the LU apart right into the gear case and I noticed that there was A LOT of play on the yoke and shaft, so I managed to locate new parts from a guy in Ontario, Norm's small engine repair super helpful guy shipped parts out reasonably fast, installed the new parts and VOILA... problem solved, I took it out water tested it, the kids and I spent an hour or so out on the water to test run it, I need to do a little bit of linkage adjustment to get it to shift perfectly, and would appreciate if anyone knows an easy way to do it right the first time. Anyways the only thing I noticed is that the boat seemed really under powered, it would not come out of the hole, would not even think about coming up on plane, I mean it is a 45 hp I should be able to tool around on the lake with 1 adult and 2 kids 11 and 8. Any ideas on how to get the power up? I did some googling when I got home and watched some youtube videos of similar engines and they were flying around. Also shouldn't I be able to pull a tube as well? Any help is greatly appreciated. Thanks

 

[wickware]

Re: 1979 45 hp chrysler prop stops turning under load

My 1970 35 hp Chrysler was clocked at approx 32 mph with just me and fishing gear. With two 200 pounders and gear, we come out of the hole ?Hard? and run WOT on top of the water with no problem in the 15? fiberglass Raycraft boat.

If it?s a magneto sys with points and condensers, I feel it?s time to pull the flywheel and inspect the points/plugs (A Tuneup). My points have only needed cleaning since 1984 from oxidation vs changing.

The fellow that helped you with the L/U sounds like the person to help you.

Good Luck!

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

Well I have 2 fm200 condensers coming in tomorrow, I went to pull the flywheel tonight but I didn't have long enough bolts, I pulled and cleaned the plugs regapped them to 40 thou I have a spark plug tester and both coils seem to have good spark, maybe it is the timing, I do also remember when I bought it the guy told me there was a bad connection at the primer bulb so it could be a fuel/air issue too. I will check the point gap tomorrow when I get long enough bolts to pull the flywheel. The plugs both looked used neither was cleaner than the other, I do have a problem with stalling when going from reverse to forward to quickly so it could very well be the timing, I would love some detailed instruction on how to check or time this engine. The fuel filter screen also looks extremely clean, anyways that is about all the info I have at this time. The guy who supplied me with LU parts is on the other end of the country from me, the guy who did the footwork and figured out the problem was me. I did pay attention a little bit when my sea-faring grandfather was giving me some lessons, but even this motor may be a little older than what he was teaching me on.

 

[jerryjerry05]

Re: 1979 45 hp chrysler prop stops turning under load

Do a compression test?

 

[wickware]

Re: 1979 45 hp chrysler prop stops turning under load

Timing compared to points should not be an issue if it has not been tampered with. Points will change and affect the timing.

Sucking air at a bad connections will give you a lack of power problems.

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

I am getting 110 psi on each piston cold. I pulled the fuel line and plugged the fuel pump end and primed it up with just air and could hear air coming out at every joint. Also noticed the glass on the fuel guage on top of the fuel cap was basically just sitting there as well, so I will replumb the fuel system and see what the scoop is. I am tempted to leave well enough alone with the condensers right now as I have good spark and both plugs appear as though they are firing, should I still pull the flywheel and check the points? Or better to leave well enough alone?

 

[wickware]

Re: 1979 45 hp chrysler prop stops turning under load

1. ?Good Point on avoiding the Mag Sys if possible and you might do the other needs 1st and avoid (if you get good results).?

If needed, I would check the points with hopes there is not a need or cleaning at the most vs burned. Just to know they are included in the lack of power.


2. Cleaning would be would be with point?s file or fine Emory cloth and lent free etc X riming filings, ?without removing the points?.

3. Most of all check the points for the .020 gap at the widest opening. 1-2 drops of oil on the point?s cam lobe felt wick, if you can not feel/see signs of oil on your finger.

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

Thanks wickware, just to be clear I still need to pull the flywheel to check the point gap and access the felt wick? Any particular type of oil? I may as well pull the flywheel if that is the case as the lake is far enough away to justify doing it before heading there as I didn't notice any lack of power when barrel tested the engine prior to finding power loss, with no resistance it seems as though prop spins full speed.

 

[btpaints]

Re: 1979 45 hp chrysler prop stops turning under load

Today's update, replumbed the whole fuel system, new tank fittings, hoses, clamps primer, everything from the fuel to the fuel pump, all nice and tight no leaks at all. Took the boat out to the lake, throttled it up and I had the same sluggishness as before, maybe a little more pep, but the water was way calmer and I left the kids with mom. Anyways got out a few hundred yards and put it in neutral and took the engine cover off and hand revved the engine, and there was LOTS of power, put it into forward and it bogged right down when I tried to hannd throttle it or use the remote. I brought it home and put some penetrating oil on the flywheel so I can check the points tomorrow, is there anything else that could potentially be causing this?

 

[wickware]

Re: 1979 45 hp chrysler prop stops turning under load

I am lost toward suggestions unless the motor?s ignition sys is not advancing in forward. My way of checking for advance is with an inductive timing light like you would check the timing on your auto. Most of all, I would not try to adjust the timing vs looking for resistance or wear if the timing mark is not advancing.

1. I added a fixed mark on the motor?s case. With the #1 cyl at TDC Top Dead Center (by feeling with stiff wire as the flywheel is turned slow by hand ?with both plugs out?).

2. When the piston reaches the top and starts to go down, I mark the flywheel at the mark on the case.

3. I replace both plugs, start the motor to idle position, accelerate and expect the flywheel mark o move away so many degrees to say it is advancing.

4. You will see a 2nd mark on my fly where I attempted to checked my timing and bailed out since it was advancing and running fine.

5. The Bottom Line! If it is not advancing look for wear, restrictions, etc.

6. The Clymer Manuel will have a ref to this info, timing and degrees of advance (?I think?).

7. Divide the # of teeth into 360 (the fly cir) to see the approx teeth related to degrees (please ck Clymer)?

Hello Pros, HELP!