Merc XR2 150 dying while in gear....

[boatin-on-cherokee]

I have a Merc ZR2 150 Blackmax and the last two times I have went out, I have encountered this issue:

After running and coming down to idle speed, it sounded like it was missing a lil bit and then it would die while it was still in gear. Then it would not start.....it would crank and crank, but will not fire. I sat there for about 15 minutes and hit the key and it fired right up!

This is not the first time I have had this issue. Can anyone provide some advice??? I can provide more details if more specific info is needed by anyone that can help me narrow this issue down.

You guys are the best and I appreciate any advice from you!

 

[boatin-on-cherokee]

Re: Merc XR2 150 dying while in gear....

I wanted to add additional info for you guys so hopefully I can get some responses going. I did have a new stator installed about a month ago, new plugs.

Could it be an issue with the lower unit? Could it be the carbs need cleaning???, and if so, is it good to use just normal carb cleaner that I can spray in there? I have heard that is not good to do, can someone please advise about that?

What about the power packs?

I can be more specific, if I know what area to be specific on........please help me.

 

[Bob_VT]

Re: Merc XR2 150 dying while in gear....

Do not use a spray carb cleaner. It does not contain the lubricating oil that your cylinders need.

Sounds like it could be as easy as one problem or a combination of a few.

When were your carbs last overhauled? Are you running a fuel filter.... is it clogging up?

Mercury has a "tuner" spray that will clean the walls of the carbs and help remove carbon from your rings and pistons. Get some sea foam for the fuel tank (do a search here in iboats for seafoam) and use the tuner spray. That is the easy way to "try and fix it"..... the more complicated method is to rebuild the carbs.

Could be the carbs, the fuel pump may be getting weak, could be the power pack.

Do you have a manual? That really should be the official first step.

 

[boatin-on-cherokee]

Re: Merc XR2 150 dying while in gear....

Thank you for the response pertaining to the fuel issue. Am planning on getting some sea foam and checkin the fuel filter. I also will check the fuel pump.

But when it comes to the power packs, "is what I am worried bout with the cost of them",.......You see, after making a run on the lake and coming back to idle speed is when it died on me. After it died, it would not start back at all, and it seemed liked it was not getting fire. But, I sat there for about 20 or 30 minutes and hit the key and it started.

This is the second time this problem has hit me while out on the water and am really concerned about the power packs. But I dont know what symptoms power packs would give off when problems start to arise.

Should I just go with the checkin the fuel issues first? And then proceed from there?

 

[j_martin]

Re: Merc XR2 150 dying while in gear....

That engine is not really that complicated, but there are several systems that all have to work right for the engine to run good.

Trying to quick fix it with spray cleaners and fuel additives will likely just extend the problem till you do real damage. Anything outside the block itself is pretty easy to fix. Anything inside can get pretty pricey.

That said, the first thing to do is a compression check, and inspect the plugs while they're out.

If compression is good, then a spark test is in line.
If it is not good, then depending on the results maybe a decarboning will bring it up (stuck rings) or maybe there's major interior damage.

If compression is or gets good, then everything else is relatively easy.

It's winter, used parts on eBay are cheep.

A manufacturer's manual is worth it's weight in gold.

hope it helps
John

 

[CharlieB]

Re: Merc XR2 150 dying while in gear....

If your fuel pump was lacking or the carb mainjets restricted you would have toasted the motor already, they both directly effect WOT and have little effect in idle issues. Poor idle mixture, dirty idle circuits, faulty carb synch, faulty idle timing, ALL directly effect idle drivability.

Compression test and Spark test are both good steps in diagnosing a problem,
if WOT performance is within RPM then I would expect testing both compression and spark will be found within acceptable range.

On-the-water idle and just off-idle problems such as this is more likely caused by a faulty link and synch and/or dirty idle jets and air bleeds. If the problem is of recent development then I lean towards dirty idle circuits. NEVER rely on chemical 'fixes', fuel additives can make some improvement in fuel flow, but air bleeds flow AIR and must be cleaned the old fashioned way, take it apart, soak it and blow it ALL out.

If this motor still has an idle stabilizer module, unplug it, then follow the steps listed in the service manual to properly set timing and carb opening, then set idle mixture while iin gear ON-THE-WATER, and finally adjust idle speed.