beginner question about tenders

[deckstar]

I have a small two person inflatable tender probably about 1.5m long, i have just bought a 4hp engine for her. When i started it up it nearly pulled the back of the boat under water do you think the engine is to heavy and powerful for it. If so what sort of size boat should i be looking for with a 4hp?

thanks

she looks like this:

 

[Searush]

Almost any solid transom rubber duck will accept a 4hp safely, but that isn't a solid transom! If you know the make of your dink, check out the web site - it should have a "safe maximum hp" for that model. The max HP is often shown on a plate on dinghies - have a close look at the outboard mounting.

Was the dinghy inflated properly? My guess is that 2.5 hp would be fine on it, but a 4hp SHOULDN'T be too much if not over revv'd. But I've only ever had solid transom dinks.

 

[JohnRob]

Is there a manufacturer's plate with a rating hidden somewhere? I see it does not have a solid transom. If it is rated for 4hp, suspect it will be susceptible to under inflation. Make sure you're well pumped up. Again, manufacturers label should give you a guide. My Quicksilver is 300psi. Oh and worth checking that the shaft is angled correctly. Usually a pin adjustment. Others on here will guess as to whether your motor is ott.

 

[Coaster]

My Quicksilver is 300psi.

Really?

However do you achieve such a high pressure?

The average car tyre would explode at much less.

 

[timbartlett]

do you think the engine is to heavy and powerful for it.

Yes.

If so what sort of size boat should i be looking for with a 4hp?

2.4m+, solid transom. I wouldn't put a 4hp on any soft-tail boat, especially not one as small as that.

My Quicksilver is 300psi.

Well that should go with a bang! (Are you sure you don't mean 300millibars? or 30.0kPa? or 3.00psi?)

 

[fergie_mac66]

Really?

However do you achieve such a high pressure?

The average car tyre would explode at much less.

agree lorry tyres are only up to 150 psi!!

 

[hlb]

. My Quicksilver is 300psi.


No It's not. It will be nearer to 3 PSI Or more likley about 8 PSI.

You would be lucky to find a garage compressor to achive 100 PSI for a truck tyre, never mind 300.

 

[Tidnock]

I have a small two person inflatable tender probably about 1.5m long, i have just bought a 4hp engine for her. When i started it up it nearly pulled the back of the boat under water do you think the engine is to heavy and powerful for it. If so what sort of size boat should i be looking for with a 4hp?

thanks

she looks like this:

Do you know if the engine is long shaft or short this would impact I would guess?

 

[landlockedpirate]

Your engine is far too heavy and powerfull for the dinghy, maximum I would use on a boat like that is 2hp. One of the older lightweight 2 strokes - Yamaha/Mariner (1980-2000 ish) only weigh 10kg. Even with a small engine I wouldnt use WOT.

As other people have said virtually any solid transom hard tail over 2.2m should be fine with the 4hp.

 

[deckstar]

great stuff! to be honest that's what i was thinking just wanted to make sure i was being stupid! The engine is a 1960's cresent so it is pretty heavy anyway!

thanks all!

 

[deckstar]

If anyone lives in Exeter and is looking for a small launch then this is up for sale. Comes with ores, seat and pump.

Make is a lifeguard

Any enquires send me a pm
Cheers