2hp Honda O/B - no power?

[kcrane]

I got a little 4 stroke Honda o/b with the new boat. I don't think it is very old (I have the manual, toolkit etc). It has a twist grip throttle, not the one with a lever on the o/b body, but no F/R gears.

It starts OK'ish - 3 or 4 pulls, then idles solidly enough. At gentle revs it works fine, pushing a 285 RIB at walking pace. It is a bit noisy (air cooled I hope, cos no tell-tail) but it phuts phuts up and down the fairway OK. I can blip the throttle to kick in the centrifugal clutch to steer and it doesn't die.

But, when I open the throttle more than a small amount it struggles, and would die if I didn't back off, as though either fuel starved or maybe too rich.

I've checked the plug (but haven't replaced it) it looks in good nick, no soot for example.

I've had the carb off (thanks to help from VolvoPaul, who I tried to encourage to become HondaPaul) and cleaned it, It all seemed fine, no blockages or sludge. I refilled with fresh fuel and it restarted fine, so the two pieces I had left over weren't important.

Only kidding about left over bits... but I still have the same problem.

I've wound the mixture screw in and out 1/2 a turn in both directions, with no real difference.

Does anyone know how many turns out from fully screwed in the mixture screw should be?

Also am I expecting too much - is it only capable of going phut phut at walking speed?

Largely this is just interest in fixing it, seems a shame not to have it right. I'll get a somewhat larger replacement when I decide what to get!

 

[elton]

Blocked air filter/intake?

 

[BGW]

I got a little 4 stroke Honda o/b with the new boat. I don't think it is very old (I have the manual, toolkit etc). It has a twist grip throttle, not the one with a lever on the o/b body, but no F/R gears.

It starts OK'ish - 3 or 4 pulls, then idles solidly enough. At gentle revs it works fine, pushing a 285 RIB at walking pace. It is a bit noisy (air cooled I hope, cos no tell-tail) but it phuts phuts up and down the fairway OK. I can blip the throttle to kick in the centrifugal clutch to steer and it doesn't die.

But, when I open the throttle more than a small amount it struggles, and would die if I didn't back off, as though either fuel starved or maybe too rich.

I've checked the plug (but haven't replaced it) it looks in good nick, no soot for example.

I've had the carb off (thanks to help from VolvoPaul, who I tried to encourage to become HondaPaul) and cleaned it, It all seemed fine, no blockages or sludge. I refilled with fresh fuel and it restarted fine, so the two pieces I had left over weren't important.

Only kidding about left over bits... but I still have the same problem.

I've wound the mixture screw in and out 1/2 a turn in both directions, with no real difference.

Does anyone know how many turns out from fully screwed in the mixture screw should be?

Also am I expecting too much - is it only capable of going phut phut at walking speed?

Largely this is just interest in fixing it, seems a shame not to have it right. I'll get a somewhat larger replacement when I decide what to get!

If none of the jets are blocked, then it will most likely be a blocked fuel filter.
Sometimes they are cunningly disguised inside the fuel tank and you need to remove the fuel tap to get at it.

 

[Ripster]

Also fuel tank breather - to allow air to get into the tank - often the fuel cap itself. easy way to test for this is to release the cap a bit and see if it revs. Otherwsie - air filter, main jet and needle (but you said these were OK), and fuel flow. Have you checked the carb float is not stuck or getting stuck and any rubber diaphrams are not punctured - assume these are all OK if you have been guided by Volvo Paul. Also assume no one has fiddled with the main jet size trying to make it go faster!! - that might cause this too.

Just thoughts...

 

[kcrane]

Um, fuel and air filters...

I didn't check them specifically, tho I had to remove the air filter to get at carb, and it seemed a simple plastic chamber. I didn't look to see if it had anything inside it!

I'll also check for a fuel filter.

It sounds like the expectation is that it should do a bit more than just pootle us along, even if it is mostly noise and fury and little extra mph.

 

[kcrane]

Also fuel tank breather - to allow air to get into the tank - often the fuel cap itself. easy way to test for this is to release the cap a bit and see if it revs.

I'll try that, good idea

 

[volvopaul]

Hi Kevin, I mentioned all those points when we met so still no joy?

What you need is that nice yamaha 8 I have!!!

 

[adrianb]

- or a Mariner 6hp 4 stroke that I have about to be put up for sale!!!!!!!!!

 

[kcrane]

- or a Mariner 6hp 4 stroke that I have about to be put up for sale!!!!!!!!!

What you need is that nice yamaha 8 I have!!!

I think I'll get whatever you two replaced your old engines with...

 

[Trumpton189]

Honda 2HP outboard

I have just acquired a 2HP outboard and am delighted with its performance. Yes it is a bit noisy but have no shortage of power. Not sure how old yours is but does it have a fuel on / off slide switch on left / rear of engine casing - if so make sure this is fully open. On first outing I failed to open this valve/ slide fully and experienced similar symptoms to those you describe.

 

[PetiteFleur]

Um, fuel and air filters...

I didn't check them specifically, tho I had to remove the air filter to get at carb, and it seemed a simple plastic chamber. I didn't look to see if it had anything inside it!

I'll also check for a fuel filter.

It sounds like the expectation is that it should do a bit more than just pootle us along, even if it is mostly noise and fury and little extra mph.

I had the same problem today when I tested my Honda 2HP (the earlier model without the centrifugal clutch). I found the fuel filter in the end of the outlet hose from the fuel tank, only discovered when I removed the hose from the tank - no indication there is a filter inside the hose. No air filter, just a simple chamber, cleaned out the carb with Carb cleaner, retapped 3 holes where screws had sheared off, reassembled and it ran perfectly in my water butt.