inflatable boats & gas motors

[mrdh]

Does anyone have experience with a 12ft inflatable Sevelor boat's ability to use a 3hp motor. Essientially my problem is that the motor does not achive high RPMs while on the boat - but does on an aluminume boat. There maybe something wrong with the pitch/tilt etc. Does anyone have a suggestion?<br />thank much<br />LP

 

[cobra 3.0]

Re: inflatable boats & gas motors

Your motor should rev full out regardless if you are running it on an aluminum boat, inflatable, ...or in a 40 gallon drum!<br /><br />I suspect a dirty carb is the cultprint or a misadjusted lean knob.

 

[crazy charlie]

Re: inflatable boats & gas motors

It is possible that the shaft is much deeper in the water when on the inflatable than when on the aluminum boat.Transom height difference??Charlie

 

[Drowned Rat]

Re: inflatable boats & gas motors

LP, That Sevylor inflatable will not go any faster than about 3 to 4 MPH. It doesn't matter if you have a 3hp or a 30hp. Your engine wants to go faster but the boat won't let it so the engine lugs after it reaches a certain speed. By doing this you are putting way too much of a load on the engine and it's not good for it. With your inflatable you should increase throttle until you hear the engine start to bog down and then back off a little. This is your boat's top speed, period. The inflatable chambers will bend in half and explode before the boat goes any faster. There is nothing wrong with your engine, it's the limitation of the boat. Good luck, hope this helps.

 

[jhoude]

Re: inflatable boats & gas motors

Ok, Lp first you do need to look at the boat size and weight and yes that can effect your speed, but if the engine isn't making top rpm's than the other gentalmen is correct you should have it serviced. Or just get a bigger engine for what trouble it's worth. As far as the 3 or 4 mph by the old chief. Yeah it probably won't pull a skier but if anyone gets onto any Ridgid Hull Inflatible web site they will see that they have a planing hull, which is made to plane (this means going over 3 or 4mph). god some people need to read more!!!!!! or just state what they know...

 

[Drowned Rat]

Re: inflatable boats & gas motors

jhoude please. Are all inflatables rigid hulls? Does Sevylor make an RHIB? Hmmmmmm?!? Don't presume to tell me what I know or don't know. I think I know a thing or two about RHI Boats.

 

[mrdh]

Re: inflatable boats & gas motors

Wow i didn't know this would arouse such passions Thank you both for your imput, let me just add a few tid-bits... I have the motor on a motor-mount and it is reinforced in several extra areas. Second I must reiterate that the motor works perfectly on land and in an aluminume boat. When it is on my inflatable the motor shows no sign of chuging, luging, or caughing. It simply does not increase its sound & RPMs past the medium speed setting. It is not that the engine tries to push and can't, or that it runs more and does not translate to speed. Several years ago I had a 5 hp and it did me well (untill it had engine trouble). I will be out on the lake this weekend again and would just like to try a few things. Any more suggestions or advice would be apprechiated.<br /><br />Thanx<br />P.S. there is a wook pannel floor for this boat - just for the record. It's a Sevlor 360 fish hunter.

 

[troska]

Re: inflatable boats & gas motors

Lilly Pad,<br /><br />The 3 hp does not have the power to get it on plane. Here is an example;<br /><br />I have an old 5hp that will plane a 12ft Al jon boat and run WOT. That same 5 hp, put on my 14 ft v-hull Al Lund will NOT plane the boat. It will NOT run WOT. At that point in the rpm range, the engine is not producing enough hp to get the hull above displacement speed. There is nothing wrong with the motor, the inflatable you have is not a planing hull. <br /><br />Tim<br /><br />

Originally posted by Lilly Pad on gas:<br /> Wow i didn't know this would arouse such passions Thank you both for your imput, let me just add a few tid-bits... I have the motor on a motor-mount and it is reinforced in several extra areas. Second I must reiterate that the motor works perfectly on land and in an aluminume boat. When it is on my inflatable the motor shows no sign of chuging, luging, or caughing. It simply does not increase its sound & RPMs past the medium speed setting. It is not that the engine tries to push and can't, or that it runs more and does not translate to speed. Several years ago I had a 5 hp and it did me well (untill it had engine trouble). I will be out on the lake this weekend again and would just like to try a few things. Any more suggestions or advice would be apprechiated.<br /><br />Thanx<br />P.S. there is a wook pannel floor for this boat - just for the record. It's a Sevlor 360 fish hunter.

 

[mjrrkim]

Re: inflatable boats & gas motors

Abc

 

[lncoop]

Re: inflatable boats & gas motors

The RHIB that my family owns came with a nice chart showing loads and top speeds from the dealer. The idea is the chambers can only take so much "squishing" (compression). Once you're at top speed (either perceived or with GPS), there's no point in increasing throttle, it's not going to do anything for you.

Seven year old thread. That little Sevylor's probably being used to patch a real inflatable by now.