Merc 260 Won't Idle Below 1000 RPM After Hydrolock

[mylesm260]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

Time to remove the pulleys then the cover if needed.
How do I lock the motor to get the middle bolt out of the pulley/crank?

THX

Impact guns work great for this.
otherwise you can try to use one of the belts and a pair of vise-grips to stop the pulley from turning.

 

[Bondo]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

Time to remove the pulleys then the cover if needed.

Nope,... More like time to Yank the Motor...

The Oil Pan goes on After the timing cover,...
The Oil Pan can't be done In the boat,.. No Clearance....
If you try'n Cheat it,... You'll have oil Leaks til you do it Right....


Btw,... To Lock up a motor,...
You pull a sparkplug,+ feed a length of soft Rope into the cylinder,...
Then bring it up against the head...

 

[soaringhiggy]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

Nope,... More like time to Yank the Motor...

The Oil Pan goes on After the timing cover,...
The Oil Pan can't be done In the boat,.. No Clearance....
If you try'n Cheat it,... You'll have oil Leaks til you do it Right....


Btw,... To Lock up a motor,...
You pull a sparkplug,+ feed a length of soft Rope into the cylinder,...
Then bring it up against the head...

when you have the pan off I would have a very close look at the rods, it does not take much once bent, well failure is not far around the corner.

 

[fabrimacator21]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

Nope,... More like time to Yank the Motor...

The Oil Pan goes on After the timing cover,...
The Oil Pan can't be done In the boat,.. No Clearance....
If you try'n Cheat it,... You'll have oil Leaks til you do it Right....
.

What, what?

You don't need to pull the oil pan to pull the timin cover... The oil pan has absolutly no relationship to the timing cover. Cam swaps are done regularly without pulling the oil pan. Not sure why you would think that.

 

[fabrimacator21]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

when you have the pan off I would have a very close look at the rods, it does not take much once bent, well failure is not far around the corner.

Very true... but you won't be able to eyeball it... doesn't take much to cause problems. If you can eyeball it then it should have a noticeable vibration when running. But, again I don't see why the oil pan needs to come off other then to check for bent rods. First thing to do is pull the timing chain cover and check your timing.

You may have also stretched the timing chain (instead of it jumping a tooth) which will lead to valves hitting pistons if not taken care of. I'd replace the chain with a double roller chain and button it back up just to be safe... could save you alot of money down the road. Theres a certain recommended amount of slop in those chains. Check that out and if it's ok then you may want to just leave it.

Depends on how many hours you have on it though... even if it's within tolerances it may be time for a new one. On cars is 100k miles then it's time for a new timing chain. Not sure what it would be for boats.

 

[Showtime22]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

Okay - Timing cover is off. Used a vise grip to hold the pulley then a puller. Does not appear to have a slipped balancer. Metal keys looked good. Appears like the dots on the gears line up.
SEE PICS

When dots are lined up - The rotor appears to be 180 degrees away from where the #1 CYL plug on the cap. Keep in mind I had it set at 20 Degrees ATDC.

I think I could be 180 out or something but I have to research installing a distributor. The distributor was never removed and used to be timed right.

Anyone see an explanation... Thanks for the help.

 

[Bondo]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

The oil pan has absolutly no relationship to the timing cover.

Ayuh,... This is a Merc. 260,... a Chevy 350,... a 5.7l,... Right,..??

The Relationship between the bottom lip of the Timing Cover,+ the Oil Pan is the Gasket between them...
The Timing Cover bottom lip is Under/ inside the oil pan, supporting the oil pan's gasket...

 

[fabrimacator21]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

Ayuh,... This is a Merc. 260,... a Chevy 350,... a 5.7l,... Right,..??

The Relationship between the bottom lip of the Timing Cover,+ the Oil Pan is the Gasket between them...
The Timing Cover bottom lip is Under/ inside the oil pan, supporting the oil pan's gasket...

Gotcha... but I still don't see why you would need to pull the pan. Drain the oil, clean it up, use a new gasket with plenty of black rtv and it should be good to go.

 

[Showtime22]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

When I buy gaskets to seal this hot mess timing chain back up - do I need to buy marine seals for the 350 or can I just go get auto 350 seals?

 

[soaringhiggy]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

When you have a good look at the balancer make sure the outer ring did not slip on the rubber insert and through the timing mark out of alignment, it does happen.

As far as the timing mark and the distributer, don't forget the cam turns at one half crank speed. The dots will line up with the dist looking like it is 180 out as the piston is coming up to tdc on the exhaust stroke not on the compression stroke, check the valves and see what stroke the piston is on before you pull the distributer.

Yes you are correct that a bend in the rod may not be visible, if the engine was out and the pan off, I would drop the head and taken the rod in for measurement and possible shot peening, but that is just me.

I also agree while you are there put in a good quality timing set, cheap insurance, I do not trust those "quite" nylon cam gears, I have seen a lot of them come apart in automotive applications. I personally like gear drives, but they are noisy.

 

[Maclin]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

To say it another way, when the dots are lined up #6 is at TDC ready to fire, while #1 is at TDC on the exhaust cycle. I think your cam is in time

 

[Showtime22]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

So that heavy balancer I took off today has 2 parts... inner and outer separated by a rubber piece?

I'll look at it in the AM. THX

 

[fabrimacator21]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

If your dizzy was never removed and it ran alright before the hydrolock then theres no way it's 180 out. It' would be spitting fire out the carb and running horribly if it was. As long as you haven't moved/touched it then your problem isn't the dizz.

 

[Maclin]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

The automotive gasket set is fine, in fact I bet you would not find a "marine" timing cover set.

And, good luck on all this....

 

[MikDee]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

On a smallblock Chevy engine, when the timing marks are lined up it, it's at TDC, & the Cam is ready to fire on #6, this is normal,,, In order to get it ready to fire on #1, you must turn the crank 180* till the timing marks on both gears are on top, and in a perfectly straight imaginary line top to bottom, but as long as they're lined up for #6, they'll automatically be lined up for #1

Apparently the weight slipped on the composite balancer, knocking the timing mark off.

So, when you put it back together, just leave it like this, and drop your dizzy in with the rotor facing #6, It'll be perfectly in time on both #6, and #1

 

[Showtime22]

Re: Merc 260 Won't Idle Below 1000 RPM After Hydrolock

The balancer is spun. Here is a pic of mine with the timing mark at the top and a new one I found on Google. You can see my crank key slot is off from the timing mark.

Thanks for the help guys. I learned a lot on this post.