Johnson GT 150 J150SLESB not starting....

90 GT 150....fully charged battery...cranks fine, but doesnt seem to be firing...will not run....could this be bad Gas, fouled plugs...???? any help would be appreciated

Checked compression and spark? Start there.

How would i check those?

You need a compression gauge and a spark tester. Compression test is pretty straightforward. Make sure you pull the kill switch, pull all wires, pull one plug at a time, insert gauge, crank it a few times, and record reading. Replace plug and go to the next one, repeat for all plugs. You want to see all levels within 10% of each other. My 93 150 reads about 92 on all cylinders. This is also a good time to check spark plug condition and gap. Make sure kill switch is pulled throughout testing and you put the wires back where they belong when finished.

Also get a spark tester and check to make sure you are getting a strong spark on each plug. I can't recall the exact setting, but I believe you want to see it jump 7/16" or so with a strong spark/snap.

First I would make sure that the kill switch is hooked up. If it is and you have the old black round lanyard connector, push in on the switch button and see if it starts. If it does just replace the lanyard with a new style red clip on connector.

thanks for the help will try that out

Yes, good idea to check this first. Try starting it without the kill switch attached, but with the button pushed down by hand.

When you do compression test though, make sure you pull the kill switch. You want it to crank but not spark. Keep it pulled throughout testing.

this is to make sure the kill switch isnt bad?

correct...more accurately, it's to check if the lanyard connection is not pushing the button all the way in. Apparently the older style doesn't always work as well as the newer red ones.

Just hold the button down by hand and see if it starts.

If not, I'd still check compression and spark. Or find a buddy that can help you out checking these. Rule of thumb when you're having problems like this is to check compression, spark, and fuel....this will usually give you a good starting point.

Remember, kill switch pulled for compression test and kill switch attached for spark test. If you get spark then your kill switch is good.

thanks for the help http://www.bassboatcentral.com/smileys/thumbsup2.gif

Do you have the old round type connector? These wear out and won't hold the button in. Kill switch off when checking compression, stops flame thrower activity. http://www.bassboatcentral.com/smileys/smile.gif

the connector looks like a fork middle prong mashed in to press button in

Then it's probably the newer style...but I'd still check it. Good luck!

Ok, thats the good one. You can tell a lot by pulling the spark plugs, if they are wet, getting fuel no spark, if the are dry no fuel. Not a very accurate method but sometimes it gives a place to start. I would check for spark first, nine times out of ten it's ignition not fuel.

i looked the other day just to see, they looked real dirty black on the ends a couple of them had oily feel to them if that is a sign of anything?

Probably just a sign that the plugs are old...but shouldn't keep it from starting usually. Wouldn't hurt to replace them if you don't know how long it has been. Black usually means carbon, so once you get it running a decarb is in order.

bought boat used from friend in 07 didnt know much about maintaing it till now learing bout it...havent changed them since i have had it...has ran good until i wasnt able to fish the last two months and now this is happening...

Replace the plugs and take the battery with you to the store while you are there. Have them test it. Maybe the battery is bad. Sometimes you can charge it forever but they just don't have anything left. They might sound like it's cranking, but not spinning fast enough.

Will the buld get hard when you pump it?

yes it is pumping fuel....has a fuel pump built in automatically pumps when key is turned on....took hose off and fuel pumps out

you can go to a local auto zone and get a spark tester if no spark then you have a electric issue trigger power pack is your power pack a t shaped?

yes CDI T shaped Looper....however i tried one more time this weekend just to see.....it sputtered twice trying to start...third time fired up...so i decided to take her to the ramp put it in the water fired right up ran fine, went down the river a little bit came back stopped fished about 20 min fired it right back up..Sunday comes and she fires right up again....???