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Old 31 August 2015, 12:20   #11
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Originally Posted by nabiul View Post
How much power would you estimate it to be compared to today?
I think it is difficult to say - in days of old the manuf's measured it at the powerhead, whilst today it is measured at the prop, after going through the gearbox. I seem to remember someone suggesting a 10% drop (that it down to 8.5HP, IF it was running perfectly, but its not - so maybe you are actually only getting 7HP out of it...

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It's difficult to have all the weight forwards on such a small boat and each of us weighing so much.
tiller extension is the way.

If it were me I would

1. Fix the engine problem - its pointless trying anything else until you do.*
2. Load it lightly, and with as much weight forward as you can (perhaps just you and a tiller extension, fuel and anchor).
3. Adjust trim and maybe engine height until happy; you said you trimmed UP - you probably want to be trimming DOWN (moving leg closer to transom) to bring the bow down and help it get over the hump.
4. Get someone to film it - so you are not guessing what it looks like - how it feels inside and outside is often different.
5. Then add more people / kit and see how it handles.

* I'd also want to check you have a sensible prop on there (so you need to know what it is, what the gearbox ratio is, what the recommended revs are, and what max revs your getting, and stick a GPS (phone in a bag) on to see what speed you are getting). If it was last on a 5 tonne sailboat pushing at 6 knots it may not be the right prop to get you on the plane.
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Old 31 August 2015, 13:11   #12
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That air cooled presumably also was old school horses so not much more than the 5 you just got rid of?
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Old 31 August 2015, 13:55   #13
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The 5 horse angler I sold was made sometime in the 60's. But yeah I am kind of wary it being a single cylinder engine and it is more than I'd like to pay; more than I paid for the 9.5 horse johnson.


I'll take a look at the motor today and see what I can do for it.
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Old 01 September 2015, 20:09   #14
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Update: The motor is bad, 60psi compression readings in both cylinders and sparks wont jump a gap more than 1/16".
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Old 08 September 2015, 15:50   #15
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The 9.8 is not a high powered engine. I have one on my SIB and it planes easily two up. We weigh about 300lbs between us and our engine weighs 26lbs, the boat etc maybe another 50lbs. So under 400lbs all up.
But my previous engine (a 6hp) took time to get on the plane.
So if you have a dodgy prop and drive with a faulty 10hp motor it's not gonna plane with over 600lbs to push along lol....
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Old 08 September 2015, 20:25   #16
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Actually we got it planing! The compression wasn't that low, I just wasn't pulling hard enough, a friend managed 70psi. We swapped out the condensers, filed down the points and reset the timing. Motor ran faster but was still hard starting and wouldn't idle well. An aomci member gave us some seafoam to mix with the fuel, what a difference that made! We were doing 15-16km/h as measured by a dodgy phone app, but we were planing!
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Old 09 September 2015, 00:22   #17
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Great stuff! Glad you got it working better. When you only have 10hp to start with it really needs to be giving it's best to get on the plane.
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Old 09 September 2015, 05:33   #18
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With the motor off, pull the cowl, give it full throttle then hold it. While holding the tiller ensure the throttle at the carb has opened full to the throttle stop. Even at 70PSI per cylinder it seems quite low. Next time do a wet compression test.

While cold, squirt a couple shots of 2 stoke oil into one cylinder at a time and do another test. If the wet-compression test reads above 100PSI and 85 or less on the other..time for a ring job. I'd check the serial number with a sight that can say what the compression should be. All and all it could need, from what your writing, a load of work including rebuilding the carb..installing a nreed valve block... Good Luck.
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