2GM20F engine issue

[Ken13559]

@Ken13559 ,
Ken, do you have a theory as to why the low compression may be what is preventing the transmission from shifting into reverse ? I fail to see a relationship between the two, but that's just me.
Keep us informed of every detail on the mechanical problems as you go along. I can imagine how you feel. It seems like a lonely, miserable, SOB right now but we're all with you on this.

I just couldn't figure out what else can cause the reversing issue. Gone down to check the Kiwiprop and it feathers easily forward and backwards as I turns the prop shaft by hand.
I will try checking & adjust the Tappets gap but doubt that to be the issue. I plan to change out the Kiwiprop to original fixed 2 blades prop.
2 scenario here:
1. if reverse is still a problem, then engine has really weaken. Some years back the compression test shows about 250psi, which is lower than spec 350-450psi.
2. if reverse is not a problem with 2 Blade prop, then it still mean the Engine is a problem because I've been using the Kiwiprop for so many years without any issue.

Doing the 5-Why still points to engine issue.
I'm ranting here.....

 

[Ralph Johnstone]

Now I'm back to square one! The repaired gearbox didn't solve my reversing problem. Now I'm thinking perhaps its due to low compression of the engine....piston & scraper rings wears?

Now I'll present the annoying suggestions : Either the Xmission or the prop is causing the problem. I just can't see how the engine is involved, regardless of how much of a piss-assed, compressionless job it's doing. Two options here :

1. Separate the connecting flanges and test the engine going into reverse. (Meh)
2. Remove the prop and test the engine going into reverse. (Best)

Unless you can dive the boat in the water and remove the prop while all the while dropping a few pieces, you're stuck separating the flanges. I presume they're aligned now so make sure each flange is WELL scored on the edges before separating to ensure they go back together properly.


Tune in tomorrow for the next thrilling episode of "As the Engine Turns"

You MUST let us know what happens.

 

[Ken13559]

Now I'll present the annoying suggestions : Either the Xmission or the prop is causing the problem. I just can't see how the engine is involved, regardless of how much of a piss-assed, compressionless job it's doing. Two options here :

1. Separate the connecting flanges and test the engine going into reverse. (Meh)
2. Remove the prop and test the engine going into reverse. (Best)

Unless you can dive the boat in the water and remove the prop while all the while dropping a few pieces, you're stuck separating the flanges. I presume they're aligned now so make sure each flange is WELL scored on the edges before separating to ensure they go back together properly.


Tune in tomorrow for the next thrilling episode of "As the Engine Turns"

View attachment 222416​

You MUST let us know what happens.

1. Done that, no issue.
2. Wanted to for last 2 weeks but water too muggy to see locking screws etc... and hence unable to remove or change prop. its in job plan when water is clearer or next opportunity to move to clearer waters.

Ken

 

[Ralph Johnstone]

1. Done that, no issue.

You have your answer, it's the prop. It couldn't be the cutlass bearing could it ?
Nah, it's the prop no matter how nicely the Kiwi prop behaves in your hands.

JUST TO PROVE WHO'S REALLY CAUSING THE PROBLEM HERE, run the engine in reverse without a prop to prove it is the Kiwi prop causing the problem.

Is there anyone nearby to look at repairing the Kiwi prop or is that a whole 'nuther kettle of fish ?

 

[Ken13559]

I've used plastic glue-gun to build a retainer as temporary fix till i get hold of the West System or other 2-parts epoxy to seal the damaged engine bay ridge.

 

[Ralph Johnstone]

Do you figure the wooden structure which built the dam has dried out yet. Looks pretty miserable from here. Don't be afraid to dig out every last piece of wet wood and then use thickened epoxy or even just cotton batten to form epoxy plugs to stop the thinned epoxy resin from disappearing into the interior of the dam.

 

[Ken13559]

Do you figure the wooden structure which built the dam has dried out yet. Looks pretty miserable from here. Don't be afraid to dig out every last piece of wet wood and then use thickened epoxy or even just cotton batten to form epoxy plugs to stop the thinned epoxy resin from disappearing into the interior of the dam.

Yah I think its has not dried out. Ok I'll trying digging it out. I was thinking, perhaps I could use Seal Stic SS106 epoxy to fill up the void after digging out the moist wood. This epoxy did good for my Water-lock cracks. So I suppose it should be good for this repair. Anyway the West System is taking too long to arrive.

 

[Ralph Johnstone]

This epoxy did good for my Water-lock cracks. So I suppose it should be good for this repair.

IMHO which is often not worth the powder to blow it to hell, anywhere there's exposed wood, I like to ensure that wood is soaked with thinned epoxy before packing anything else over top for shape. I like to plan ahead for about 25-30 years into the future so that when I'm getting on to 105 to 110 years old, I'm not faced with a bunch of failures which I could have been prevented 25 - 30 years ago if I'd just taken the time to do it right.

 

[Ken13559]

This probably why my engine overheated after sailing. SCW pump needs priming each time when engine starts. Thought was Anti-siphon valve issue but it tested good. Then removed all beddings from rear berth for work on engine and finally saw sea cooling water spraying out of the Primex Silencer.
Red arrow points to where crack is.
Sealed with hand kneed epoxy.
The crack on Silencer nozzle was very likely due to the engine vibration and weight stress by the corrugated-wired Exhaust Hose (Trident 252). Hose was suspended between U Mixing Elbow and Silencer due years of shortening/cutting of damage ends during maintenance.
Outstanding repairs in coming weeks:
1. Replace with stock 2 blades prop
2. Do Compression Test

 

[Ken13559]

.......
Is there anyone nearby to look at repairing the Kiwi prop or is that a whole 'nuther kettle of fish ?

No one here could service the Kiwiprop. Got a friend going to NZ for a month or two. Maybe I'll get him to bring the prop to Mr.Kiwiprop, the manufacturer himself over at Auckland, NZ.

 

[Ken13559]

Dug out as much balsa wood i could from the ridge. Good thing is the base fibreglass. So apparently the balsa wood rings within the ridge line. I stuff the void with Seal Stic SS106 epoxy.
Next task is to change to stock 2 blades prop and do Compression Test of both cylinders. Tiring....tiring....

 

[Ralph Johnstone]

You've determined the problems, you're in the final lap, slide into home base and you're finished. The first outing without the problems will be all the sweeter.

 

[Ken13559]

I did Compression Test on both cylinders. It average about 250psig. Not much different from what I got years ago.
I also put in a set of new Injectors. Run the reverse test and it made no difference.
So it's back to square one.
I can still get by with very little use for reversing in next couple of weeks. Will try swap in a 2 blades flex-o-fold when water visibility is better.
Sorry couldn't upload video of Compression Test as file size too large for this site.

 

[Ken13559]

Ordered 2"x4" Buck Alongquin gland shaft hose, now just discovered on this site stated that our 1" shaft uses 1_3/4" gland hose

"Stuffing Box, Bronze, For All Hunters W/ 1 In. Shaft Hose and clamps included. Fits 1-3/4 in. hose."

 

[Ralph Johnstone]

@Ken13559 , you're going to have to keep a journal that question was tossed around back here :

Shaft Packing Gland tube/hose

If the motor & shaft are in alignment the hose pretty much just sits there holding water outside the hull. If something causes the shaft to wobble the hose will start to get a work out and water will try to enter the boat. Then it is only a matter of time. Actually, every time the shaft turns...

forums.sailboatowners.com

I guess the owner's manual didn't lie.

 

[knackers]

check that a reversing roller has not fallen out of the kiwi prop. had same problem with reverse

 

[RoyS]

Question your compression gauge results. Examine your gauge assembly closely. There should be a check valve at the injector adaptor inlet right at the engine head injector port and not any further away from that port. If the check valve is not there, the volume of air in the injector adaptor will cause a low reading in your compression results.

 

[Ken13559]

check that a reversing roller has not fallen out of the kiwi prop. had same problem with reverse

Reverse roller are all there and free to turn by hand.

 

[Ken13559]

Question your compression gauge results. Examine your gauge assembly closely. There should be a check valve at the injector adaptor inlet right at the engine head injector port and not any further away from that port. If the check valve is not there, the volume of air in the injector adaptor will cause a low reading in your compression results.

Noted. Will look for the check valve at injector adaptor

 

[Tipsynippertoo]

I too have a Kiwi prop. Your symptoms are exactly what I get if the prop' hasn't been serviced. The proplem is the Kiwi, don't spend any money on the engine, the fault (if it were the engine) would happen if it was in forward or reverse, the engine doesn't know which way the prop' is turning! The black smoke is the engine bogging down because it can't rev, just the same as being in a diesel car in too higher gear.
You need to ensure that the little rollers are free to turn, and the whole hub is working as it should. The reason the engine is bogging down is because the blades are not at the correct pitch in reverse.
In the UK you can send the prop' to Kiwi and they will overhaul it for you. But there is nothing in the prop' that is difficult. Here is quite a good video about servicing the prop: