Starting the motor without muffs

[Ed Haugh]

Would any harm be done by starting the motor and letting it run for literally 3-5 seconds WITHOUT muffs before shutting it down?



This would certainly improve my boat launch times.



I am still running an "old technology" motor - '99 Merc 150XR6



I think I know the answer (hell yes, that will cause damage), but would like to understand how / why as I think about the many air-cooled 2 cycle motors out there.

 

[Randy Janousek]

It is not an overheating problem, but one of a dry water pump impeller. It just takes a few seconds to damage the impeller without water.

 

[Dan J.]

You will be burning the vanes of the impeller in the pump housing when you spin it at hundreds, let alone thousands, of RPM's without water cooling it. When those vanes burn and curl or break off you will lose water volume and pressure through the cylinder head and BOOM one of a multitude of rapid fatal metal fatigue errors will arise. (Piston seize, wrist pin walk out, etc.) Your engine is water cooled, not air cooled. Running dry is never a good idea.

 

[THOMMO59]

The other issue you could face is if your motor hasn't been started for a while, the impeller blades can almost stick to the stainless housing and without water as a lubricant, I've seen impellers literally fall apart.

 

[FLsportsman]

I agree that

 

[dan huff]

My question is why? Ive been boating 30+yrs and have never needed to start my motor prior to launch. As a followup for anyone,I had a guy tell me awhile back when he was showing me his new to him boat that his motor didnt pump water for the first several minutes till it warmed up. It wasnt "peeing" as he called it when first started. It was an older xr mercury 150. Ive never had a motor that to my knowledge didnt start pumping water right away.

 

[Dan J.]

The thermostat(s) need to open up before you'll see much visually. It's pumping and circulating, but flow is restricted until operating temps are achieved.

 

[dan huff]

His didnt appear to pump any water for the three or four minutes it ran. He also said that about thermostat. I just thought it was odd as the Mercs Ive owned all seemed to pump water after at least 30seconds. I thought he had a problem an urged him to have a tech check it out before he hit the water.

 

[Ed Haugh]

Thank you. I knew it was not good for some reason. Overheating - no. But I had not considered the impeller grinding away on a dry surface. Enough said.



Why? Because I have still not perfected starting this motor. I am much better, but it still takes a little longer than I would like. I would to launch and have it turn over on the first crank - like it does after it has ran for a few seconds...



Thanks again guys. Appreciate the responses.



Oh, and my motor does not pee for about 1 minute either - 'til the stats open.

 

[Jim B]

Danfromwindsor, thats exactly how my xr6 was. On muffs it took a good 5 min before the stats opened.





Ed H, what are you doing procedure wise to start your motor for the first time when you launch? If it differs from below try what i put down there in the morning when you launch. When i had my XR6 it started every time without fail using the method below no matter the season.



1) pump the ball

2) trim the motor so its level(this is important, up is bad)

3) turn the key so that it beeps but do not crank

4) press in the key(enrichener) for 5 seconds, do not crank yet

5) turn the key and crank it while still pressing the key in until it fires and runs

6) release the key and let it warm up.

If it sounds like its sputtering hit the enrichener a couple times until its idling normal

One key to this is DO NOT advance the throttle at all, it will make it hard to start and tend to want to flood.