Timing chain/tensioner?

[Golflover]

Hi Forum,

I'm attaching a link

to my video for your review of an intermittent startinf issue I've had with this boat for a couple seasons. Eventually, I can always start the boat, but during my attempt today to lay up the boat for the season it has became increasingly more difficult to start it. In fact, my attempts to start it quickly drained the new battery near dead.

Today it took me a while, but eventually it started and ran fine. I shut it down three times to see what it would do. It started up right away 3 times, but on the fourth, it reverted back to the same symptom as seen in the video.

My question is: In your opinions, is this demonstrative of one issue like a loose timing chain/tensioner, or could there be several issues causing the same issue?

Thanks for all your input and any insight would be greatly appreciated.

Kurt

 

[thumpar]

Re: Timing chain/tensioner?

If it was the timing chain it would still turn. Sounds like a starter or bad ring gear teeth. For your sake I would hope it is the starter.

 

[alldodge]

Re: Timing chain/tensioner?

This looks to me to be bad cable connections. The starter is not getting full voltage to crank or the starter slave solenoid is not fully engaging. The clicking and or grinding is the contacts engaging and then releasing. Put a volt meter of the starter terminal and see what it does when you hit the key, I'm guessing it will go all over the place.

There are no timing chain tensioners on Merc engines

Edit: Stony "post 10" I should never say "no" meaning all - my error again :facepalm: no tensioners except on 470's

 

[thumpar]

Re: Timing chain/tensioner?

Good thinking AllDodge. The connections would be the first to check.

 

[84EdH]

Re: Timing chain/tensioner?

I agree with above, (one of them anyway ) the crank pulley turns with the crank, the camshaft would run off the timing chain, so you would see the crank pulley turning with the flywheel speed (and your not). I tend to agree with Thumpar, but would not bet money against All Dodge.

 

[Golflover]

Re: Timing chain/tensioner?

First off, I am truly grateful for all of your insight. I have learned a ton already.

I will check all the connections in your suggestions. A further question, since I don't have an alternator, any chance a bad stator would cause this issue?

 

[thumpar]

Re: Timing chain/tensioner?

First off, I am truly grateful for all of your insight. I have learned a ton already.

I will check all the connections in your suggestions. A further question, since I don't have an alternator, any chance a bad stator would cause this issue?

No. What is going on is that the starter is not turning the motor over.

 

[Golflover]

Re: Timing chain/tensioner?

Thanks Thumpar, that makes sense. I know it's tough to know, but is it more likely this is a connection issue or is it equally possible that ring gear teeth are missing? If the ring gear is defective, is there a way to confirm it without pulling the motor?

Thanks, Kurt

 

[alldodge]

Re: Timing chain/tensioner?

Thanks Thumpar, that makes sense. I know it's tough to know, but is it more likely this is a connection issue or is it equally possible that ring gear teeth are missing? If the ring gear is defective, is there a way to confirm it without pulling the motor?

Thanks, Kurt

Pull the starter and look at the flywheel teeth

If the teeth were messed up I believe there would be a bunch more real load grinding noise.

 

[stonyloam]

Re: Timing chain/tensioner?

There are no timing chain tensioners on Merc engines

There IS a timing chain tensioner on the 470 (3.7) engine.

 

[stonyloam]

Re: Timing chain/tensioner?

My guess the armature on the starter is bent (or broken) and is rubbing up against the field coils (not uncommon in the 470 starter) and causing a huge current draw which drops the battery voltage causing the solenoid to cycle rapidly. Pull the starter. IMHO it is unlikely that the timing chain tensioner is the problem. But I have been known to be wrong

 

[achris]

Re: Timing chain/tensioner?

I'm with Terry... That looks a lot like a starter-motor problem. If it was a connection problem I would not expect to hear that clattering noise, just to see it turning slowly, or not turning at all, and the bad connection point getting REALLY hot.... That looks like the starter solenoid dropping in and out rapidly.... So, my vote is with the guy I share the title of 'dumbest on this site' with, Terry.... :lol:

Chris......

 

[Golflover]

Re: Timing chain/tensioner?

Thanks to each of you for parting with your infinate wisdom. I'm not afraid to undertake removing and replacing the starter if that's what is required. It appears to be a nuts and bolt operation. Is it tougher than it looks and are there any nuances I need to be aware of?

Thanks, I'll post back my progress.

 

[thumpar]

Re: Timing chain/tensioner?

Starters are not hard to pull unless the boat construction is in the way. Make sure you remove the + off the battery before you do it.

 

[stonyloam]

Re: Timing chain/tensioner?

It appears to be a nuts and bolt operation. Is it tougher than it looks and are there any nuances I need to be aware of?

Yeah it is nuts and bolts, It will drive you nuts, any you will bolt strong drink. Nah, the the support bracket can be a pain (easiest to unbolt it from the block as I recall) and it is a tight fit getting it out from between the block and the exchanger and be sure to get on the right bolt head behind the block (get on the nut with a box wrench, and a ratchet on the back). Here is a parts diagram showing the bolts and bracket: http://www.mercruiserparts.com/Show...nbr=10&bdesc=STARTER+MOTOR+AND+WIRING+HARNESS

 

[stonyloam]

Re: Timing chain/tensioner?

Make sure you remove the + off the battery before you do it.

For safety's sake make sure you remove the negative from the battery first.

 

[achris]

Re: Timing chain/tensioner?

For safety's sake make sure you remove the negative from the battery first.

Oh, come on Terry. Now you're just being a big girl.... All that can happen is a shower of sparks as the spanner loosening the positive terminal hits the engine block.... How bad can it be? I mean, the spanner will get hot, and the battery could exploded... You're right.... !!! Hey, OP, remove the negative terminal first!!!

Chris......

 

[thumpar]

Re: Timing chain/tensioner?

In my boat the battery is to far away from anything to matter but I guess in some yes. Plus the - on mine takes 10x longer to remove because of location.

 

[achris]

Re: Timing chain/tensioner?

In my boat the battery is to far away from anything to matter but I guess in some yes. Plus the - on mine takes 10x longer to remove because of location.

If the cables are that long, ever thought of just turning the battery around? :facepalm: :lol:

 

[thumpar]

Re: Timing chain/tensioner?

I am actually going to be redoing the battery cables this spring when I add the 2nd battery and put in an isolator.