Help with motor please?

[Hukeedo]

I took my boat out for the first time after completing the project this weekend. The boat is a 15 ft tri-hull open bow and I put a 1960 Johnson SS 40 Hp RDSL-22 engine on it. The boat ran good except it does'nt seem to go fast enough. Seems like it needs more throttle or something but the throttle is opening all the way.
Also,There are some tilt adjustments on the motor, would changing the position help? Not sure what to set them on. Also, is there a standard starting point for the lean/rich adjustments on the low speed and high speed side? Seems like they need adjusting too and not sure how to do it.
One more point: the fuel in the tank i was told by previous owner was a 50:1 mix, I ran out of gas in the middle of the lake and put some 25:1 mix in it and it did'nt seem to run right afterwards.
Any help and info would be greatly appreciated.
Thank you!

 

[jonesg]

Re: Help with motor please?

I guess "the project" was the boat, well now you have the second part of the project do do, the engine is just as important.

Do yourself a biggie and get the factory service book
www.outboardbooks.com
you need the model number to look it up.

Go through it from the top, compression test.
spark gap test (get a gap tester from an auto store)
then order rebuild kits for the carbs and do them.
Then set the mix using Joe Reeves directions in the faq files here.
Change the lower gear oil, use new seals on drain screws.
remove prop and check for fishing line, lube and reinstall prop.
Inspect the coils for cracks.
New plugs, champion only.
Install a tach and see what you get in the water.
Try a tiny tach (google it).

 

[lindy46]

Re: Help with motor please?

That motor uses a 24:1 gasil mixture. I'd adjust the tilt to the second or third notch - should sit fairly level on the transom. Initially set the high speed knob open 3/4 to 1 turn and low speed about 1-1/2 turns. Yes, check compression before wasting any money on other engine parts. If compression is okay (100psi+ and both cylinders within 10%) then check spark. If you have spark and compression, take the motor out on the lake and open her up. Adjust the high speed for optimum performance/speed. Then adjust low speed for optimum idle.

 

[Hukeedo]

Re: Help with motor please?

Thanks for the info JonesG and Lindy46, i will definately buy a manual for the engine. I did check the compression when i bought it, it was in the 108-112 range.
I will check the spark and put new plugs in it, probably needs em. Now the guy i got it from said the carbs were rebuilt about a year ago.
thanks again for the info.

 

[lindy46]

Re: Help with motor please?

Compression sounds good. If the coils are good and you have good spark, you should be good to go (assuming the PO actually rebuilt the carbs) May be all that's needed is adjustment of the high spped and low speed jets.

 

[Hukeedo]

Re: Help with motor please?

I checked the plugs today and decided to just put new ones in, and low and behold, when i pulled the wire boot off the top cylinder, i found that the plug had a broken insulator tip! So it must have been running on 1 cylinder. Is that even possible for the engine to run on one cylinder? I put new plugs in and i'll run it this week and adjust the carbs .It seems like that was what it was doing becuase of the lack of power. Should'nt a 40 hp runs pretty fast when well tuned?

 

[lindy46]

Re: Help with motor please?

Yes, they'll idle pretty good on one cylinder but won't run good at high speed. Looks like you found your problem