1994 120 HP rebuild. Now I'm scared.

[brian66r1]

Hi.

Had a lot of dramas last year. The boat has been in the shed for 12 months. The power head has been off and apart. Had broken rings on 2 pistons, 1 piston had a bit of scoring and the number 1 cylinder had a bit of scoring. Re-bored number 1 cylinder 10 thou over, Honed the other 3. 4 new Wiseco piston kits and gasket set. Taking my time. You know.

Just last week put the block back together Done everything right so far, followed all the hints and tricks contained within these forums. Pretty sure everything is OK.

Got a friend to help me lift the power head back onto the boat. Went on really easy. Put the lower cowl back on, OK, had to take the fuel pump off to fit the lower cowl over the power head (remember that anyone who reads this). Bolted the exhaust cover back on. Did all the wiring, followed the diagrams in the manual I downloaded (didn't appear to have my model in it) (forgot to take photos,(remember everyone, take photos of everything)). Checked the battery terminals, no short. Touched the terminals onto a battery, acceptable little spark, tested the trim, switch up, engine goes up, switch down engine goes down, ignition key on and the fuel gauge moves, the tach moved, the back lights on the instrument lit up. Looking good. Even tried turning on the cabin lights and they came on.

Now I have to connect fuel and try starting the bastard. This is why I'm scared.

Have I done everything right???????

I'll keep you posted.

Brian

 

[Frank Acampora]

Re: 1994 120 HP rebuild. Now I'm scared.

Why afraid? If it doesn't start, there will most likely be a problem with ignition---however-- If it was running before, it should fire right up now.

Just be aware that if you used a lot of assembly lube, it may be difficult to crank and when it does fire, it will smoke like a coal fired steam engine. You may need to squirt in some 50-1 premix to loosen it up.

But, once it does start, you will have a feeling like no other: Wonderment, surprise, and pride.

 

[pnwboat]

Re: 1994 120 HP rebuild. Now I'm scared.

Manual also recommends running 25:1 oil/fuel mixture during the break-in period. I also have a warning sticker on my 1988 Cobra Bayliner right next to the fuel filler cap that says the same thing. 25:1 during break-in, 50:1 after break-in. Take it easy on the motor during break-in and you should be good to go. Good luck!

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

Remixed fuel 25:1. Connected fuel line pumped it up. Took a hose off 1 of the choke lines. Pressed the key in ignition on. Fuel came out. Idle lever up. Cranked a couple of times. Nothing. Tried again. Nothing. Pulled the plugs. They were all dry. Put about 5 mls fuel in each cylinder. Tried again. Still nothing. Plugged a spark into one of the leads. Have spark. Will try and cover one of the carb inlets and make sure it is sucking and delivering fuel in a little while and see what happens.

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

Pulled the cover off the top carb. Placed my hand over it. Friend turned the key. Sucking heaps. Pulsing like I imagine it should. Fuel comes pouring out the front of the carb like it did before I tore it down. I get spark and there's fuel in the carbs. The plugs don't get wet from cranking?????

Brian.

 

[Frank Acampora]

Re: 1994 120 HP rebuild. Now I'm scared.

You put fuel directly into the cylinders and it didn't fire. If an engine has fuel,air, and spark at the correct time it MUST fire.

So, When you put fuel directly into the cylinders, you flooded it and would have needed to crank without choking until it cleared itself out and fired.

If you did this, then the next logical thought is the plugs. Sometimes they will fire in air but not under compression. Were the plugs new?

Next thought is that you wired the triggers or coils incorrectly so the cylinders were firing at the wrong time. Double check the ignition wiring. If at all possible, compare it to a running engine.

Don't give up-- it may seem frustrating but all will turn out well.

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

The plugs were new after I first started having problems. They are the correct buzhw type. The engine has never run whilst these new plugs have been in. They are still brand new. I have pulled them out after cranking and they are dry. I took video of 2 old plugs connected to 1&2 coils and although the spark was not bright blue. It was there none the less. And when I stopped and started the video. You could see them firing at alternate times. Not jumbled up or anything like that.

I had photos of the trigger connections on the switch block and they are all back the same way.

I appear to be back to where I started from.

What if I pull the idle jets out again and blow through the carbs again?

 

[pnwboat]

Re: 1994 120 HP rebuild. Now I'm scared.

I don't think that I would mess with the carburetors just yet. Make sure that the throttle linkage on both carbs are "sync'ed" up, and the carburetor throttle butterflys are working together in sync. I would suspect like Frank mentioned that you may have flooded the motor. Sounds like you have gas, and spark. It should at the very least pop or backfire. Make sure the battery and battery connections are all in good working order and the starter is spinning the motor over fast enough. The slower the motor turns, the lower the voltage generated for the ignition system. Sometimes starting a "fresh" motor takes a little more time than one that has been running.

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

If you had a good working motor. Put clean or new plugs in and disconnected the kill wire from the switch block. Cranked the motor for 10-15 seconds maybe 3 or 4 times then pulled out the plugs, would they be dry?

I'm also going to pick up a timing light this afternoon and test the timing just to make 100% sure the triggers are all connected to the switch block OK.

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

I just checked timing and 1 is firing at 10 gegrees before tdc. I put the light onto 3 and the timing moved to about 90 degrees around the flywheel. Put the light onto 2 and it moved to 180 degrees. Put the light onto 4 and the timing was at about 270 degrees on the flywheel.

All the trigger connections are connected correctly on the switch board (block). I have to go racing on my friends big boat now. A beneteau first 45. It's a hard life. I'll come back this arvo and put a couple of drops of oil into each pot and try it again on the big battery and see what happens.

Brian

 

[Frank Acampora]

Re: 1994 120 HP rebuild. Now I'm scared.

Timing sequence is correct as firing order is 1324 and 90 degrees apart. HOWEVER. If you are saying that at wide open throttle the timing is only 10 degrees BTDC, then at idle and start, it is about 20 degrees after TDC and the engine simply won't start. Normal timing is 30 degrees BTDC at wide open throttle and somwhere within 2 degrees of (0) at idle.

If however, you checked timing at neutral or start position, then it is advanced 10 degrees and while the engine should start it will melt pistons at wide open throttle.

In any case you now need to check that the flywheel key did not shear and the flywheel skip timing. You also need to check the trigger position and the linkage between it and the timing tower for correct setting. The two plastic blocks should have somewhere around 3/8 to 1/2 inch between them.

I have seen them both ways, but I believe the correct orientation is the plastic block that the threaded rod passes through is attached to the trigger and faces the inside--toward the crank with the locknut under the flywheel. Also, before you adjust you need to position the threaded rod so both sides are equally threaded into the plastic blocks--you can see the center because it is threaded both left and right hand. Thus screwing one way will close the gap and screwing the other direction will open the gap

 

[TwoFish]

Re: 1994 120 HP rebuild. Now I'm scared.



This is the only shot I have of the linkages. Hopefully it is of some help.

My 1998 75hp idle setting was 8 degrees BTDC and at WOT it was 30 Degrees BTDC (dynamic), 32 degrees BTDC (Static). This was printed on a sticker ontop of the block and also what is stated in my manual.

Cheers

Dean

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

Hi everyone.

Made an incredible discovery this afternoon. When I attach the timing light to the plug leads whilst the leads are attached to the plugs in my test board. There was spark. Enough for me to check that each coil was firing when it should. Then when we connected the plug leads back onto the plugs screwed into the motor, the timing light stopped working.

The plugs aren't firing when they are screwed into the motor. I re checked the resistance on the windings on the stator and they are all wrong. I think I need a new stator.

The ignition isn't getting enough charge from the stator the fire the plugs under compression.

I think my engine has a 398-8778A23 stator on top of it. A CDI 174-8778K1 stator is a replacement for this one, it is also listed as a replacement for a 398-8778A22 stator. Can anyone tell me if a stator 398-8778A22 is compatible with my motor?

Brian.

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

It lives.

I bought a new old stock stator last week. It came in the mail today. I put the stator on tightened the flywheel down. Connected up the wires. Primed the bulb. Turned the key. And after 3 or 4 seconds of cranking? Vrmmmmmmmmmmm.

How sweet that sound was. It's in a tub of water now. Water was pissing out through the idle relief ports like it should. It was idling a bit high in neutral, I turned it down to 1100 rpm in neutral. I set the timing at about 5 degrees BTDC at idle. I will wait till I get it in water proper before I set the timing at WOT and then set the idle running in neutral tied to the jetty.

Now I'm not so scared.

All there is to do now is get it in the water and make the last adjustments and run it in a bit. How do I do this?

Thanks everyone.


Brian.

 

[TwoFish]

Re: 1994 120 HP rebuild. Now I'm scared.

I Like a story with a happy ending.

Well done.

 

[SkiDad]

Re: 1994 120 HP rebuild. Now I'm scared.

Good to hear ! I remember that sound when I was out of commission this summer for about a week - when I put that stator in and it fired up with a new authority

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

Not such a happy ending as it seems.

I've been running it in a large plastic tub 3 or 4 times in recent days and it's been going fine. Run for about 10 minutes each time and it stalled once or twice for no reason but it started again and ran no problem.

Took it out in the bay yesterday. Started in the marina fine. Left the marina and noticed it bucking a bit and missing a bit too. It revved ok. It reluctantly went to 3500 - 4000 revs a couple of times. When I say reluctantly. I mean it hesitated a bit but it was nothing too bad. I still hadn't properly set the timing yet and I put it down to that.

Anyway. I stopped just inside the mouth of the river and pulled up to take a look at the timing. Had a hard time starting it after then. It would start and run. Rough though. And only with the high idle lever up (quicksilver control). I manged to get it moving quickly drop the high idle and throw the throttle forward. And it took of. Not the best but ok. Ran to 4000 - 4500 revs sort of ok.

Pulled up, dropped the anchor tried to fish for a couple of hours. Went to start. No! Tried again. No! Choked (push the key in and turn it) and high idle lever and it starts but really rough. Stalls every time I drop the high idle lever. Cannot get moving. Pulled the plugs. Grey muddy murky mess all over them. Water in the cylinders. All four. Put plugs back in and ran for 10 seconds or so. Dropped the bowl off the top carb and the fuel is nice. Definately no water in it.

Coast guard and water police to the rescue.

I pulled the head off this morning and at a glance. The new head gasket I fitted 3 weeks ago looked ok.

If the Head gasket seems ok. Where can water be getting into all four cylinders. What could I have forgotten. In the gasket set I got. There was a lot left over. One thing that troubles me is the long length of thin orange rubber almost like an oring type of thing. I didn't take one of these out when I pulled the power head down. Where is this from?

The saga continues.

Thanks in advance.

Brian.

 

[brian66r1]

Re: 1994 120 HP rebuild. Now I'm scared.

Not such a happy ending as it seems.

I've been running it in a large plastic tub 3 or 4 times in recent days and it's been going fine. Run for about 10 minutes each time and it stalled once or twice for no reason but it started again and ran no problem.

Took it out in the bay yesterday. Started in the marina fine. Left the marina and noticed it bucking a bit and missing a bit too. It revved ok. It reluctantly went to 3500 - 4000 revs a couple of times. When I say reluctantly. I mean it hesitated a bit but it was nothing too bad. I still hadn't properly set the timing yet and I put it down to that.

Anyway. I stopped just inside the mouth of the river and pulled up to take a look at the timing. Had a hard time starting it after then. It would start and run. Rough though. And only with the high idle lever up (quicksilver control). I manged to get it moving quickly drop the high idle and throw the throttle forward. And it took of. Not the best but ok. Ran to 4000 - 4500 revs sort of ok.

Pulled up, dropped the anchor tried to fish for a couple of hours. Went to start. No! Tried again. No! Choked (push the key in and turn it) and high idle lever and it starts but really rough. Stalls every time I drop the high idle lever. Cannot get moving. Pulled the plugs. Grey muddy murky mess all over them. Water in the cylinders. All four. Put plugs back in and ran for 10 seconds or so. Dropped the bowl off the top carb and the fuel is nice. Definately no water in it.

Coast guard and water police to the rescue.

I pulled the head off this morning and at a glance. The new head gasket I fitted 3 weeks ago looked ok.

If the Head gasket seems ok. Where can water be getting into all four cylinders. What could I have forgotten. In the gasket set I got. There was a lot left over. One thing that troubles me is the long length of thin orange rubber almost like an oring type of thing. I didn't take one of these out when I pulled the power head down. Where is this from?

The saga continues.

Thanks in advance.

Brian.

 

[SkiDad]

Re: 1994 120 HP rebuild. Now I'm scared.

why would you not adjust the timing before going fast ?

 

[pnwboat]

Re: 1994 120 HP rebuild. Now I'm scared.

The long thin orange rubber seal goes between the both halves of the crankcase. Not all motors use it. For the motors that do use it, there is a groove in the mating surface of the crankcase halves that it sits in. If you motor does not have the groove then it is not used.

If you are getting water in the motor, then I would suspect that you may have used the wrong exhaust cover gaskets. There should be two of them. There are several styles and the bolt pattern is the same. Make sure that you have the correct gaskets installed.