Running a motor with no water?

[ba229]

My motor starts fine most of the time at the start of a trip (ie first pull just like it should) but sometimes it can take 5 or 6 pulls to get it going.

This is no drama except when in a fast moving body of water.

So recently i have been starting the motor while the boat is still on the trailer just to make sure it will fire.

This running of the motor with no water lasts no more that 2 seconds.

Am i doing any damage to the impellor or other components?

[Tezza985]

Have a chat to Burley Boy. I think he's learned by his mistake!

NO WATER! NO IMPELLER!!

Tezza.

[ba229]

Yeh I responded to that thread with my own little story.

Just wanted total confirmation that it will harm the impellor.

[NQCairns]

Yes damage will result.
If you must do it, Start your motor at home on the muffs before leaving then (if not a long trip) you should be fine to see if it kicks at the ramp.
I can only assume this is what all the boofheads (not you Ba your on ausfish ;D)have allready done when they start their rig up just before launching, big rigs too! could be just to make a person jump! seen it a hundred times at the ramp, still confounds me. :P

[Kerry]

And 2 seconds running with a dry impellor is about all things need to stuff up especially considering that between trips things dry out and when one hits the starter/cord it gives the impellor a real quick hurry up in a dry housing from a standing start.

In the water it's not that bad as generally its had time to fill the leg housing with water etc. But even so hitting the key is instant motion.


Cheers, Kerry.

[wacco_fozzy]

Saw a guy recently pull up at the ramp at Kings Beach Caloundra that opens into the surf swell on the headland with a tinny on a trailer.

He backed up, dropped the boat off onto the concrete and after parking the car, started the motor while still dry and waited for a good couple of minutes until the right swell arrived and he pushed the thing into the water, jumped in and took off.

From what you are saying I'd say he will have a maintenance problem soo.

[blaze]

Hi Wacco
yeh, he is gana have a real prob one day, doesnt take to long for the rings to grab in the pistons.
cheers
blaze

[DavidT]

Hey Peoples,

New here, but a quick question.

How long should one leave teh fresh water going through the engine after a days trip?

I have an Evenrude 50Hp 72 Model, i ust want to make sure i am giving it the clean out it needs.

Cheers,

David.

[blaze]

Hi David
Firstly welcome
I reckon about 10 minutes is the go
cheers
blaze

[DavidT]

[smiley=2thumbsup.gif]

Ta Blaze

[ba229]

Thanks for the reply guys.

I have done it maybe 4 times and thought i had better check before continuing.

Am due to check the impellor anyway so will see if there is any damage.

[Dignity]

I was once told by an OB mechanic to run it for 15 mins. What I do is flush the motor as the first job, then start unpacking the boat and cleaning the fishing gear etc. As this usually takes about 15 mins it works out perfect. Salt will build up quite considerably inside the water jacket in very tight places especially with short runs and idling near the ramp etc and it needs this amount of time with heat and fresh to make sure you totally eliminate it (so I have been informed). Hear a lot of peoples around hear who only flush for about 60 secs, reckon they will have probs down the track.

[Kerry]

15 minutes is way to long for an outboard to be idling over especially under domestic water pressure.

As for idling at the ramp this can be very helpfull to an engine (both 4S & 2S) that has just done a run through crapy water as the amount of water any outboard injests is quite considerable and idling at the ramp can in many ways help burn off any unwanted mositure as well as letting oil settle where it's most needed as immediately shutting an outboard down simply lets the water settle where it's really not meant to be.

Really the worst thing one can do is roar up to the ramp and shut an outboard down and then let it cool down as one will never get the operating temp back up at home idling on a hose and the last thing one wants to do is rev the guts out of an outboard while on a hose.

Preventative maintenance is not something that simply occurs when one gets home.

As for the question? with consideration to how the outboard is shutdown anything more than 5-6 minutes is probably a waste of time and really does nothing for the overall health of the engine and for those 5-6 minutes certainly nothing above idle 9especially 2S's) , one really wants the oil to settle not blasted out the exhaust. #

Cheers, Kerry.

[DavidT]

I was once told by an OB mechanic to run it for 15 mins. What I do is flush the motor as the first job, then start unpacking the boat and cleaning the fishing gear etc. As this usually takes about 15 mins it works out perfect. Salt will build up quite considerably inside the water jacket in very tight places especially with short runs and idling near the ramp etc and it needs this amount of time with heat and fresh to make sure you totally eliminate it (so I have been informed). Hear a lot of peoples around hear who only flush for about 60 secs, reckon they will have probs down the track.

Hello Dignity,

My problem is, my Engine is bloody loud. Those old 2 strokes make alot of noise and running it for 15 minutes would probably make the neighbours see red.

It is a pitty there are no mufflers available to put on them to reduce the level of noise.

One last question; Is it best to just let it go on idle or does it make a difference to rev it up alittle?

Cheers,

David.

[Burley_Boy]

I'd say the problem is the dried salt clogging things up. Thus the quicker you rinse the motor after use the better and I suppose it stands to reason that if its had time to dry then you must rinse it for longer to get it clean. There are a few holes that are small and readily clog up and one of those is the tell tale hole so if you keep clogging your tell tale you know that you've got a fair bit of gunk in there.
I had a good look when I stripped mine down and I must say after the clean up I could excavate with the tell tale.

2 secs I wouldn't know but with the speed the impellor hits and the friction involved your impellor must loose its edge after any more than 10 secs, I'd not do it again at all as even if it keeps workin bits of it will break off and clog the system as mine did.

Kerry seems to know what he's talking about so I'll start by letting mine idle a bit at the ramp although I'm only 2 minutes from the ramp.

[Dignity]

David, there are now silencers available for flushing OB's from 40 - 200 HP - Cost around $60. Don't know how they perform. I usually have mine running at just above idle.

Kerry, had an 85 merc and used to only run it for about 5 mins. I had a problem with the big end bearings and when stripped down saw how much salt gets into every nook and cranny. I had an 85 suzie after that and faithfully ran it 15 mins. Had to take the power head off to replace the seal at the bottom and took the opportunity to check for salt build up - nix, zip, zilch. Running a 150 merc at the moment and I haven't had to do anything to it yet but hopefully it will be fine. Maybe the other problems I hyave had can be related to the length of time I flush but I wouldn't have thought so.

[DavidT]

David, there are now silencers available for flushing OB's from 40 - 200 HP - Cost around $60. Don't know how they perform. I usually have mine running at just above idle.

Kerry, had an 85 merc and used to only run it for about 5 mins. I had a problem with the big end bearings and when stripped down saw how much salt gets into every nook and cranny. I had an 85 suzie after that and faithfully ran it 15 mins. Had to take the power head off to replace the seal at the bottom and took the opportunity to check for salt build up - nix, zip, zilch. Running a 150 merc at the moment and I haven't had to do anything to it yet but hopefully it will be fine. Maybe the other problems I hyave had can be related to the length of time I flush but I wouldn't have thought so.


Dignity,

Thanx for the reply :)

I guess i will start hunting aroung tomorrow for one, i really do need one, it is just way to loud when flushing the engine, and i really dont want to just do quick flushes to make sure i dont upset the people in my street.

Once again thank you for the reply.

Cheers,

David.

[Dignity]

I looked in the BIAS catalogue, haven't checked Whitworths or Glascraft but no doubt they would also stock them. Seems the ranges are 40-50,60-115 and 130-200hp - all same price

Sam

[DavidT]

I looked in the BIAS catalogue, haven't checked Whitworths or Glascraft but no doubt they would also stock them. Seems the ranges are 40-50,60-115 and 130-200hp - all same price

Sam


Actualy i am on my way to BIAS tomorrow, i will get one from there if they stock them, it is only around the corner for me and less travelling required.

My only problem is they allways talk me out of a sale for some reason.

Cheers,

David.