Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this OK.

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

AMD Rules in his project mentioned the exhaust port bolts on MERCS snapping off if one was not careful. Is that an isolated incident or that can be overcome with certain precautions?<br />Spraying WD-40 on those bolts and letting them sit for a couple days before trying to remove them would help?<br /><br />Alex

 

[andy6374]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

WD-40 is okay, but something like PB blaster would do a much better job. Let the bolts get really soaked. When trying to remove the bolt, if it feels like its going to snap try and tighten instead. It's better if you work the bolt back and forth. If you can get your hand on a MAPP torch this would help as well.

 

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

What is a PB blaster? What is a MAPP torch?<br />Thanks<br /><br />Alex

 

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Where are you Rodbolt? If one is successful in getting the bolts out of the exhaust port would you replace them with something different in case of future problems with the powerhead?<br />What is a PB blaster and a MAPP torch?<br /><br />Alex

 

[AMD Rules]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Whoops. Didn't see your note Alex. I only wish I went south for the winter...lol<br /><br />Thanks for the comments on my rebuild log. I enjoyed doing it twice. On my motor all of the bolts were easy to remove. Nothing broken.<br /><br />Hardest part of the rebuild was getting the pistons back into the block without the proper spring compressors. Most annoying part was installing the lower unit for the hundredth time.<br /><br />Blaster PB is a penetrating catalyst used to free siezed & rusted parts. Apparently a good one.<br /><br />A mapp torch is a multi application torch, using Mapp Fuel. MAPP (Bernz-O-matic) fuel is made by combining liquefied petroleum gas with Methylacetylene-Propadiene. Useful for freeing rusted/siezed parts.

 

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Thanks AMD Rules(could you not change your name to something shorter)<br />The cylinder bore micrometer was expensive?<br />There is a specialized tool for inserting the pistons? Is it expensive or can one rent one?<br />Blaster PB available in Canadian Tire stores?<br /><br />Alex

 

[AMD Rules]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Originally posted by crem1:<br /> Thanks AMD Rules(could you not change your name to something shorter)

You can just call me AMD... that'll do lol.<br /><br />

Originally posted by crem1:<br /> The cylinder bore micrometer was expensive?

The inside micrometer kit I used is expensive, but I borrowed it from work. Basic kits start at about 160USD.<br />

<br />There are a variety of bore gages available, and cheaper solutions such a telescoping gages etc. Lots of options.<br /><br />

Originally posted by crem1:<br /> There is a specialized tool for inserting the pistons?

There are ring compressors available specifically for inserting multiple pistons at once. You need one for each piston.<br /><br />

Originally posted by crem1:<br /> Is it expensive or can one rent one?

I did not look for pricing. I doubt many marine service locations would loan out that type of tool. Anything is possible. <br /><br />

Originally posted by crem1:<br /> Blaster PB available in Canadian Tire stores?

If you look near the bottom of this thread, apparently it is not available in Canada yet.<br />I think Canadian Tire may have something almost equivalent.

 

[rodbolt]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

hahaha<br /> if you can get that inside mike set into that 2 9/16ths bore you have racoon hands. but the average size teenage hand or larger just wont work well. thats why ya really need to use a dial bore and set it with an outside nike, but thats just my opinion. I may have done one of those motors here and there.

 

[AMD Rules]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Call me a racoon...lol<br /><br />No doubt about it, for people who do it a lot (like you) there is a proper dial gage for the job. For me, I don't always have the tools and use what I can get my racoon hands on.<br /><br />It had the extension handle to rotate it with.<br /><br />That inside mic set worked great for me.

 

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Sounds like it would make sense to buy all these<br />instruments only if you were planning to go into marine mechanics. I assume it costs about $20.00 a hole to do a hone in a machine shop.<br />But IMAGINE the thrill and self satisfaction that one would get in seeing and hearing the motor go like it has never gone before.(Shades of STARTREK). Very spooky<br />Thanks Rodbolt for all your insight.<br />Thanks AMD. Did you use any outside aids aside from wrenches to get the bolts off? <br /><br />Alex

 

[jleus]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Best thread I have seen on any DIY site in a long time.

 

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

All because of the nice guys(experts) that we have, Rodbolt, AMD Rules, Clams Canino, Andy6347, and ED MC.<br /><br />Alex

 

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

"leak down test" for questioable cylinders was mentioned by andy6347 in one of the topics. Can andy, Rodbolt, or my old buddy Tim Mathis explain how this is done. <br /><br />Alex

 

[andy6374]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

You need a leak down tester. They are expensive ~$300. They pressurize the clyinders and it measures how much air can exscape, or leak, from the cylinders and is a measure of how well they are sealing. I am not sure, but I think most mechanics will say that anything over 10% is no good. You might be able to get one cheaper on ebay.

 

[jleus]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

If you can manage the motor repairs you can manage building yourself a leak down tester. I built one for about $40.00 but thats using the hose from a quick disconnect (from the gauge) type compression tester and fittings that were in the "multi-faceted" (read junk) drawer. You need two good gauges. Both that read in pretty fine increments. You want to know you are dead on 100 psi on the first gauge and a good gauge that you can see 1-2 psi increments on the 2nd. The key is an orifice between the two gauges. It has to be 0.040. Google leak down tester.

 

[Clams Canino]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

This thread is still going??? <br /><br />-W

 

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

What does Clams Canino think about the "Leak Down Test"?<br /><br />Alex

 

[crem1]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Somebody mentioned the fact that you have to use a compressor for each cylinder that you have when inserting the cylinders into the powerhead. Four compressors for four cylinders. How exactly is this done since I see piston rods attached to the pistons. Don't you have to knock the cylinders into each bore using some kind of mallet. Or do you insert the cylinders first into the bores then attach the piston rods? That does'nt make any sense.<br /><br /> As you know I have a MERC500 so the cranckcase is attached to the pistons when being inserted into the powerhead.<br />Perhaps I'm overlooking the obvious and can't see the forest for the trees. <br />Thanks<br /><br />Alex

 

[Clams Canino]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Originally posted by crem1:<br /> What does Clams Canino think about the "Leak Down Test"?<br /><br />Alex

Overkill. If the compression tests OK and the reeds are OK - the sucker will run OK. That simple.<br /><br />-W

 

[AMD Rules]

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Re: Mercury 150 Ring Gap .040 (STD) on honed cylinder within tolerance - is this

Some, but not all inlines require you to install the rotor as an assembly (crankshaft, pistons, rods, bearings, etc) all at once.<br /><br />Highlighted in yellow below is four ring compressors used simultaneously. It would be a similar process for an inline 3 or 6 cylinder.<br /><br />Two of those shown are 'offset' compressors which are extra wide to go around the crank offset. The other two are simple straight compressors.<br /><br />