1970 9.5 hp Seahorse Johnson won't run

[Blazin]

I have rebuilt the carb and checked the spark on my 1970 Johnson outboard. Everything checks out OK. The motor will not run in anything but full choke. After today the motor started and ran great in my driveway, but as soon as I got it to the lake it would not even begin to start.<br /><br />Any suggestions I am completly frustrated with this engine now!!!<br /><br />Thanks

 

[alcan]

Re: 1970 9.5 hp Seahorse Johnson won't run

Hi Blazin<br />Did you do a compression test on this unit? What were the results? Did you have the tank vented at the lake? When you over hauled your carb did you set the float by the book?

 

[Blazin]

Re: 1970 9.5 hp Seahorse Johnson won't run

Compresion cheched out. Carb is set by the book. tank was vented. When it does run if I shut off the choke it dies. it will run at 1/2 the RPM with 1/2 choke.

 

[JB]

Re: 1970 9.5 hp Seahorse Johnson won't run

Howdy, Blazin.<br /><br />Sorry, but everything does NOT "check out". Johnson did not make a 9hp in 1970. You have a fuel starvation problem, most likely a gummed high speed jet in the carb.<br /><br />Other possibilities: Restricted venting of the tank, air leaks in hoses, failing fuel pump.<br /><br />If it runs "OK IN THE DRIVE" it may be running on one cylinder.<br /><br />If it will run with full choke, pull the fuel inlet line to the carb and turn it over. If the fuel pump produces strong squirts of fuel into a bottle, you have a gummed carb.<br /><br />If not, try pumping you primer bulb. If that will not produce squirts into the bottle, purge and clean your fuel tank and check the vent for restriction.<br /><br />Let us know what you find.

 

[Blazin]

Re: 1970 9.5 hp Seahorse Johnson won't run

JB,<br />I will try those suggestions. I am sorry I checked the motor and it is 9.5 hp Seahorse although still not sure about the year.

 

[Boatist]

Re: 1970 9.5 hp Seahorse Johnson won't run

Blazin<br />yes Johnson did make a 9 and 1/2 up until 1973 when the 9.9 and 15 came out.<br />You said you did a conpression check but did not give the numbers. The more info you share the more likely someone can help you. When you rebuilt the carb are you sure you Got float set right and set the low speed jets right?? Have you changed the plugs and gaped to .030??<br />From what you say sounds like fuel. How old is Fuel?? If you pull plugs and squirt a little fuel in put plugs back in and try to start what happends?? A weak spark can look ok with plugs out but blow out under compression. I would start by squirting some fuel in carb. If it starts then starts to die squirt in a little more. If it runs that way you can be sure it is fuel. Check for water in fuel, the inline filter, make sure the low speed jet is adjusted, make sure the high speed jet is open, make sure float is working and needle is not sticking, and make sure float is set to proper level. If you give the guy here the info they will get you on the right track without any info just a total guess.

 

[Blazin]

Re: 1970 9.5 hp Seahorse Johnson won't run

Well guys,<br /><br />I went to check out the engine this morning and i am getting a strong squirt from the fuel pump and it squirts with the primer bulb.<br /><br />But I did find I had no spark, pulled the fly wheel and the pin was sheared. I found that strange since I had spark yesterday. I am also going to try new plugs today. The fuel is 1 week old.<br /><br />I will start today with a new flywheel key and get back to you.<br /><br />Boatist:<br />I dont have any numbers unfortunatly on the compresion, but i can tell you it is OK. I will double check the jets and float on the carb as well. <br /><br />Thanks for any help so far.

 

[Blazin]

Re: 1970 9.5 hp Seahorse Johnson won't run

Thank you everyone for any input that was given. Once I replaced the flywheel key it runs like a champ. I have full RPM and it idles.<br /><br />Thank You Everyone!!!!!!<br /> <br /><br />Blazin

 

[Boatist]

Re: 1970 9.5 hp Seahorse Johnson won't run

Good Job, Glad to here you got it going. Make sure you get flywheel good and tight because if it is lose a clough or backfire can sheer Keyway again.