Bumping engine at launch

[nightstalker]

I see a lot of guys at the launch bumping their engine while still on the trailer to make sure it turns over before dropping it into the salt. One guy last Sat. bumped it 3 or 4 times and then the engine actually jumped to life for a second or two before he was able to shut it down. Couldn't this cause damage to the water pump? <br />Stalker

 

[DJ]

Re: Bumping engine at launch

Yes-no question.

 

[Cricket Too]

Re: Bumping engine at launch

I don't really think a (1) quick bump will hurt just to check that your batt. will do the job, I do it before I even leave my house if the boat has sat for a while, doing at the ramp is too late if you ask me, what are you gonna do if it's dead and your halfway down the ramp? Bumping it 3 or 4 times is pointless if it cranks 1 time it should be good to turn the motor over, (provided the engine is in good tune). Letting it actually start dry will no doubt hurt the impeller, especially if it has some age on it.

 

[DJ]

Re: Bumping engine at launch

mmcpeck,<br /><br />No offense, but that's what a $20.00 (in dash)volt meter is for.

 

[DHPMARINE]

Re: Bumping engine at launch

Hi All,<br />Years ago I had a customer that was doing this.After 4 water pump jobs in one season he had educated himself.Just think...rubber impeller...stainless steel cup...no lube.<br /><br />DHPMARINE

 

[JB]

Re: Bumping engine at launch

Moving to General Outboard.

 

[rickdb1boat]

Re: Bumping engine at launch

So are you saying that there's enough water going to the pump when cranking it in the water at first start? even on old Mercs that take awhile to start? Curious...

 

[DJ]

Re: Bumping engine at launch

RB,<br /><br />Not at all. With the engine down, the water pump is actually submerged. Remember that the water pump sits right on top of the gearcase split. It's there for a reason.<br /><br />You just do not see the results (telltale) of its pumping until the engine block is full.

 

[rickdb1boat]

Re: Bumping engine at launch

Thanks DJ. Just wondered if the pump actually ran somewhat dry before running. I have seen many guys that only submerge the prop and start her up. Can't be good...

 

[Cricket Too]

Re: Bumping engine at launch

DJ...I agree with you on that one, but I was just answering the question at hand. Besides I have seen plenty of batteries that will read 12+ volts and cannot crank and engine properly, gauges are good and I probably should get around to installing one, but they don't tell you if you have a weak cell and not quite enough amerage. Sometimes my small boat sits for a month, I just bump it real quick to see if that battery is actually gonna perform, not drop to 8 or 9 volts as soon as it gets a load on it at the ramp.

 

[DJ]

Re: Bumping engine at launch

mmcpeck,<br /><br />I understand your point. I always do two things.<br /><br />1. Look at he guage-key on.<br /><br />2. If it runs the tilt, at the proper speed, it will crank the engine.<br /><br />If an engine has sat for a long time, that "bump" is what can tear the rubber blades away from the impeller hub.<br /><br />Don't fret, we all have done it and still do.

 

[BassMan283]

Re: Bumping engine at launch

What I like are the guys who fire the motor up in the rigging lane and rev it a few times to warm it up. Usually only see this with pull starts.

 

[AW]

Re: Bumping engine at launch

I have done this for years with both electric and pull start engines and never had a water pump problem of any kind.<br /><br />Yes even occasionally revved it up dry. Never for long though.

 

[Forktail]

Re: Bumping engine at launch

We surf launch here a lot. The surf can be nasty. If your outboard doesn't run immediately, you can easily capsize the boat and hurt someone. <br /><br />So our outboards must get dry-started prior to launching. We pretty much launch them on a daily basis, so the impellers always have a little moisture/water on them from the day before's flush, and this is usually enough to do zero damage to the impellers. In fact we have some outboards 7-8 years old that have the original impellers in them, which are working perfectly.<br /><br />For outboards that have been sitting a while, we flush them with the muffs before trailering to the beach. Again, this way dry-starting does no harm.<br /><br />If the impeller has any wetness on it at all, it should be fine for a short dry-start.