@Way2slow @imbatman, hmmm the quarantine must be getting to you guys. 

Nope!  As stated, I just made my last post on the subject.  What's that old saying about arguing with an*****.  I've tried to explain, and it's not getting anywhere, so I give up.

On 4/9/2020 at 5:10 PM, WRB said:

What plug are you running? I believe the 250 XS uses Champion IZFR J6's @ .042 gap.

The plugs look OK color just tired. Can't judge the gap? it looks excessive.

Tom

 

@WRB

 

ngk izfr6j-11 spark plugs. There is another plug that can be used that's a bit cheaper. It's in the manual but forget which it is. 

 

I've checked gap multiple times and it's good. 

 

Think im planning on trying to decarb the engine and throw a new set of plugs in her as my next step. 

You might want to try the S&F sight also.  There used to be a whole lot of guys on there that live and breath Mercury's.   I used to do lot of technical advising on OMC's on there but since I've gotten out of the hot rod motor stuff, I rarely get on there anymore.  The last time I was on there, I got bombarded by people that said they been looking for me and wanting to know how to do different mods on their motors.  It's probably one of the best technical sites on the web or at least used to be.  

@Way2slow you been on b b c boards ? Through doing my own research on different things I've found a lot of good info on there. 

 

Will check out s&f, thanks

It's been a long time since I've posted on that site.  There is one guy on there that seems to think the OMC Johnson/Evinrude site is his an gets very upset if you mention anything about modifying a motor.  He only knows the factory stuff and will run someone off if they mention mods.  

 

Just for kicks I logged into S&F for the fist time in a couple of years, I had 11 notifications from different users so I logged back out.  On there, I don't use my screen name I use hear.  I had to change to keep people from doing a search and finding me and getting bombarded with question it's been to long since I done the stuff and would have to research a my notes now to find the answers.

2 hours ago, Way2slow said:

You obviously know absolutely nothing about a two stroke engine and are ungodly hard hardheaded.  I don't care if there is even no rings or even a piston in the cylinder, IT IS NOT POSSIBLE TO PRESSURIZE A TWO STROKE ENGINE CRANKCASE FROM THE SPARK PLUG HOLE DOING A CYLINDER LEAK DOWN TEST. 

 

I'm done, have a nice day.  

WOW your need for a sense of superiority is just amazing.  Not only do you continue to try to belittle someone you yell at them while doing it.  I bet dollars to donuts you would not do the same thing in person.  Like i said before this is almost an integrity test when someone reacts as you do by yelling at people.

 

The video you posted is of a 4 stroke now that I go back and look again. Please take the time to look and tell me if I am wrong.

 

It is possible to pressurize a crankcase during a leakdown,  heck that is one of the things you are testing for and the reason you use low PSI.  In the perfect world the rings are fine but once again I say if the wall is scored or the rings are broken you will pressurize the crank case and pop the seals using 100psi.  There is no reason to use a high PSI on a 2 stroke.  10 psi or 100 psi will show you a leak and why use so much pressure when it is not needed and can hurt the motor more.  

 

I know the mod on *** you speak of and he has given more good advice than most and has saved folks money and heartache.  Seems you just try to crap all over anyone that has a diff idea to offer if it does not match yours.

 

All I can say is you guys have google and can look this stuff up for yourself and see how folks are doing it.

2 hours ago, FordsnFishin said:

@WRB

 

ngk izfr6j-11 spark plugs. There is another plug that can be used that's a bit cheaper. It's in the manual but forget which it is. 

 

I've checked gap multiple times and it's good. 

 

Think im planning on trying to decarb the engine and throw a new set of plugs in her as my next step. 

Champion is the factory brand NGK are good plugs.

Good luck it's appears from afar your engine is tired and so is this thread.

Happy Easter

Tom

On 4/8/2020 at 6:02 PM, FordsnFishin said:

After doing the WOT test appears they're burning pretty well. All seem pretty identical. 

I’m no engine mechanic or expert but those seem to have a pretty big gap?  I did a quick google search and it says .042-.044 gap recommended.  Those seem a little bigger than that?  Hard to tell  with the pictures though.  They the insulator doesn’t look like they are fouling though. 

I'm with WRB on the plugs.  NGK is a good plug and a lot of the Mercury racers run them, but I always run the factory brand.  If the factory installed Champion, when going with a new set, I would go with Champion.  However, that would be another good question to ask one of the guru's on S&F.  A lot of the racers run NGK, but those engines are so modified, there's not much left of what the factory did.  Another thing, check into Mercury's thoughts on an engine that see's very little WOT and a lot of idle.  I know some manufactures recommend going one range hotter on the plugs under those conditions.

 

Sorry for getting it off track, but that's over and done with, so I hope it doesn't discourage you from continuing posting, and asking questions as they arise, and keep us up to date on what you find as you go through the process. 

As of right now, my plan is to try and decarb the engine. An throw some new plugs in the ol girl. 

 

I'll let you guys know what I get after that. 

 

For vehicles I've always used seafoam. I've seen good results on cars I've had. Tempted to use it for the boat and start pouring some in the fuel to treat it. 

I'm a major fan of SeaFoam,  years ago, a friend that worked at a parts warehouse got me 15 cases at $24 per case ($2 per can) and I use it in everything.  Hate to see the day the last can is used, for what that stuff sells for now.  I have never tried to use it decarb and outboard but I doubt it would do much good.   The Mercury sells works pretty well.  A friend of mine that was a tech rep for OMC, back when they were in business, said the additive that Yamaha makes works but never tried it either.  OMC/BRP's and Mercury's are the only two I've ever used.

You will also hear of using water, and I've used water on car engines before tearing them down, that works great, but I've always been a little gun shy of trying it in a good motor or an outboard.  During WWII they used it in airplane engines, kinda like a shot of nitrous when they needed a sudden burst of power, but the engine was removed and rebuilt after they used it but it will definitely clean the carbon out. 

 

Now, if you are talking about just adding it to the gas, I almost always do that.  If you happen to have some left over from a trip, it will keep it fresh a lot longer than just letting it sit.  It also does good at keep the shellac cleaned out, but don't think it would do much for the hard carbon buildup around the pistons and rings.  It does good and preventing it, but not sure it would do much for removing it.

On 4/12/2020 at 10:08 AM, WRB said:

Champion is the factory brand NGK are good plugs.

Good luck it's appears from afar your engine is tired and so is this thread.

Happy Easter

Tom

I believe ngk are factory. The 3 recommended plugs in the original mercury manual all recommend ngk plugs.

 

@Way2slow seafoam is widely used to remove carbon. I had always done this on vehicles by pouring it into vacuum lines. 

 

Been doing some research, couple various methods for outboards. Directly spray in to plugs, turn over a few times to make sure everything is coated than let sit over night and take it out and run it. 

 

Dunks method, 3/4 gallon fuel 16oz seafoam in a little gas can and run the engine for 15 minutes with the heavy solution, let sit for half hour, than take out and run it wot.

 

If you have a fuel filter, remove and fill 3/4 way with seafoam, replace and run for 15, let sit, run again.

 

Still doing some reading on how exactly I want to do it yet. 

 

 

Thanks, I may try some on and engine I plan to pull the heads or tear down and see what it does on a hot running engine.  I know it won't touch the carbon on a cold piston.  

I'm a fairly avid shooter and have experimented with just about everything known to man searching for something that will dissolve that hard carbon ring that forms in the throats of a rifle barrel. I would do this by using a piston that had a carbon buildup on it and using different solutions on it to see if it would dissolve it.  After 24 hours SeaFoam would not phase it.  It would not even make a black spot on the rag I wipped it off with.  Aqua Seal carb cleaner would take it off, but that stuff was a little harsher than anything I wanted to soak the inside of a good rifle barrel in.  So, it's still a lot of scrubbing with a bronze brush and bore cleaners.

@Way2slow from what I've watched and read it's a must to have it at operating temperature. I think that's key. 

 

Sort of like you mentioning using water. Basically using the water as a steam cleaner. 

 

Just got a big tub set up to fill with water and run some seafoam through it. We'll see how it does. The company seafoam shows filling the inline filter with it. That's my plan of attack. 

The water I think is more like nitros.  It vaporizes and induces a whole lot more oxygen, making the EGT's sky rocket and just burns it clean.  That's why is so dangerous to use it.   A crack or leaking head gasket that's letting water into a cylinder will make it melt the piston in a heartbeat.  A whole lot of people that owned the early 60 degree OMC V-6's (150's) learned that one the hard way.  The early production years had a casting flaw that cracked and let water into the cylinder and they melted down.  It can also spike the compression and cause break a ring and one of the groves around the piston.  That's why I would never use it on and engine that I was not tearing down to rebuild.

 

I've seen a lot of people that say they do it.   However, that's like using starting fluid in a diesel, I've seen a lot of people do that, and I rebuilt a lot of diesel engines with broken rings and pistons back in my working days that they did that to.  Kubota's were the worst about breaking with starting fluid sprayed in them.

Cooling water shouldn't be getting into the cyclinder chambers? You can mix Seafoam with water in a spray bottle and spray it the carbs or  injectors tubes while the engine is running about 2000 rpm's to burn off carbon. I would use the old plugs for this, lots of smoke and carbon debris exhausting. Just don't over do this as the high oxygen tends to burn the piston tops.

Tom

 

I've done two cycles of seafoam inside the fuel filter now. One time I ran about half a can of spray seafoam through the intake while light throttle on the lake. Hot soak, then run WOT for 5 minutes or so. She seems to be idling better, lots of smoke, and seems to have done some much needed cleaning. Even cleaned the carbon buildup inside the prop. 

 

About to put on the new plugs and index them. 

 

@Way2slow get you a can of ballistol aerosol. Works wonders on cleaning carbon from guns. 

I've used it for years for a quick clean and wipe down when I don't have time to do a full cleaning or on a trip for several days and the stuff is great, but with some powders, it still won't get that doughnut without some work.  H4831 cleans like a breeze after several rounds but after a hundred or more, it gets hard.  Varget, and some of the Reloader powders, on the other hand does not clean worth a darn even after a few rounds.  Matter of fact, I have almost totally quit using Varget because of that.  I have one heavy load that I have not found a powder as good in my 223, but that load is used at 1,000 yards and since I rarely shoot it that distance anymore, I live with it.  Pretty much stick with the 6.5 stuff for that now.

If you do much shooting and have a barrel that copper fouls, Barnes CR-10 removes copper about the fastest of any I've tried, and over 55 years of shooting, there's not many I haven't tried. However, I don't think I would want to get it anywhere near nickel plating.  I has a very strong ammonia base to it.  I have a couple of barrels that for some reason, the last four inches will foul after a number of rounds and the Barnes takes it out with cotton mop and reasonable effort, and no brushing. I hate having to run a brush through the bore.  When scrubbing the throat, I use an undersize brush (it doesn't hurt to reverse an undersize brush) and only scrub the first few inches of the barrel.