97' Fast Strike 150 no power under load

[doral19]

Hi there,

I have a 1997 Johnson Fast Strike 150 with model number BJ150GLEUE. I bought the motor brand new 3 years ago as it was from a guy that never used his boat. It has about 30 hours into it. I stored it for 6 months and when I used it idling was good. Neutral has good power to about 4-5K rpm.

The problem is when I put it on forward I can only go up to 1,500 rpm and the motor sounds like it's misfiring and coughing. Checked all the plugs and they all look good. I already bypassed the fuel filter to rule out it's clogged.

Next thing to check will be spark test and to pull out each spark plug wire while idling to check if they are working.

I don't understand why on neutral I can rev up the RPM but not on forward.

Could this be a linkage issue? Or electrical?


Any other tips would help.



Thanks!


Francis

 

[Bob_VT]

Re: 97' Fast Strike 150 no power under load

An outboard will rev all the way up without running on all cylinders. It is not a good idea to rev an outboard in neutral.

If you have spark in all 6 cylinders ..... I would attack the carbs. It sounds as if it is not getting adaquate fuel and based on the age.... I would rebuild the carbs. I can only imagine that there are clogged passages just from age.

 

[jspano]

Re: 97' Fast Strike 150 no power under load

my 86 115 did the same thing. it had a fuel leak where the two parts of the motor bolt together. it doesn't leak in neutral only when there's a load. i had to pull the cover and have some drive the boat to see it. check the number 1 cyc. that was mine. there is a fuel bypass chamber that del. fuel from the carb. to the cyc. once i seen the leak i checked the cyc back home with a air hose and some soapy water. i disconnected the battery and removed the plugs and rotated the fly wheel to get it in the right postion.

joe

 

[SparkieBoat]

Re: 97' Fast Strike 150 no power under load

motor may be low hours..but age has certianly affected the carbs, and fuel lines. I would check all fuel lines, and rebuild carbs, also change water pump impeller and foot oil. Check spark with a spark gap tester.

 

[doral19]

Re: 97' Fast Strike 150 no power under load

Hi guys!

Thanks for all the tips. Here's what I did to further diagnose.

I let the engine idle while pulling each spark plug. all plugs have good spark but 3 of the 6 has spark but when I pull the plugs, the idle does not change. So I think there's something wrong with the 3 cylinders.

Next thing I tried was to throttle using the throttle lever on top of the engine. As soon ask I move it, the engine chokes and eventually dies.

3rd test was to cover the air intake of each carb. When I do this for the cylinders that are OK (meaning the engine coughs when I pull the hi tension wires) the engine dies. When I cover the air intake of the carbs that don't work, nothing happens.

I suspect it's something to do with these 3 carbs.

I want to remove the carbs and bring to a mechanic since I am 4 hours away on a beach. I have some mechanical background and have pulled carbs of jetski's.

Is there a link to instructions of how to remove my carb? I would appreciate if someone can email me (francis.campos@datasolutions.ph) or send me a link.

I can't get a service manual here in the Philippines and would have to get it from the US.

If someone can send me the part just to remove the carbs that would be great.


Thanks!


Francis

 

[CharlieB]

Re: 97' Fast Strike 150 no power under load

Cleaning carbs is always a good idea, especially since the motor has sat for such a long time, fuel residues are sure to have restricted passages inside.

I would NEVER clean/rebuild 'some' of the carbs, ALWAYS do them ALL. It would be a sad thing to clean half of them then take the boat out and melt a piston on the UN-cleaned side because of a small fuel restriction of a dirty main jet.

Before removing the carbs there is one more test to try. Mix a pint of fuel at 50:1 in a squirt bottle then spray it into the carb throats of the non-running cyl's at a idle. Do the cyl's now fire? If yes then carb rebuilds are required. If No, then test spark again at an idle using an inductive pick-up of a timing light of tach to ensure that the ignition is working correctly.

It is possible for J/E ignitions to drop one side at an idle if a shift interrupt switch is malfunctioning.

 

[SparkieBoat]

Re: 97' Fast Strike 150 no power under load

get a spark gap tester from your local auto parts store...the ole yank a plug wire and listen for a change is not a reliable method..you need to see what wires are firing.

 

[jonesg]

Re: 97' Fast Strike 150 no power under load

Hi guys!

Thanks for all the tips. Here's what I did to further diagnose.

I let the engine idle while pulling each spark plug. all plugs have good spark but 3 of the 6 has spark but when I pull the plugs, the idle does not change. So I think there's something wrong with the 3 cylinders.

This test you did does not tell you whether the problem is spark or fuel.

You cannot use a sparkplug to test ignition because the spark has to be strong enough to jump 7/16th inch , thats almost 1/2 inch gap to be good.
You can use a peice of wood with 2 nails spaced 7/16th inch to test for sufficient spark. But a spark GAP tester is simpler to use if you can get one, where are you located in the philippines?

Rebuilding the carbs is simple enough, run wire thru the jets, remove the drain screw in the bottom of the bowls and run a wire thru, see if theres any junk in that hi-speed jet. All you really need is the new seals for re-assembly.
http://www.youtube.com/watch?v=o5cx...07A9BA566&playnext=1&playnext_from=PL&index=2

And you should consider buying the factory service manual from ebay.

 

[jspano]

Re: 97' Fast Strike 150 no power under load

see if this helps

http://shop2.evinrude.com/ext/index.aspx?s1=e06ffbae85d69c9031ba543332590b03

joe

 

[tashasdaddy]

Re: 97' Fast Strike 150 no power under load

not using motors, the carbs foul due to evaporating gas, leaving varnish in the carbs, blocking the jets. through carb cleaning, and rebuild kits. using old gas can do the same thing. do you have a fuel/water separator?

 

[ezeke]

Re: 97' Fast Strike 150 no power under load

Check your shift assist switch; it may be out of position.