Mariner 20 Won't accelerate

[Scondo]

Hi all .<br />I have a Mariner 20 that starts and will idle ,but with a little vibration.it will engage into gear at low rev's but as soon as i accelerate to go it will start to rev then cut out.It seems that it is only under load ,because when it is in neutral and i rev it at the carb it will rev??

 

[dolluper]

Re: Mariner 20 Won't accelerate

Use a spark tester {$ 10 auto store] and check your spark with plugs in block should get 3/8 " spark that,s real bright and good snap otherwise time to check ELECTRICS or CARBS go from there

 

[Scondo]

Re: Mariner 20 Won't accelerate

Thanx dolluper.<br />I cleaned carb and found the check ball in primer had beed forced up the spring so sorted that and re set the float level which was to high.it sems better and will accelerate .when tied up in the harbour it will run at pull power fine,when out in open water it will seem to cavitate (rev up)and then bite for a while then cavitate.It won't stay at a constant rev??

 

[dolluper]

Re: Mariner 20 Won't accelerate

If what your discribing is the motor is surging it would be an air leak carbs,fuel line,fuel pump or tank not venting on the other hand if runs and just rev,s higher and doesn,t push the boat then check to see if the prop hasn't spun, spines in the prop worn

 

[Scondo]

Re: Mariner 20 Won't accelerate

Thanx Dolluper<br />I took it out again and it was better when i played with the tilt on the pins on the transom,but it would do it a little ,i will check the fuel line etc.