no power to my 90 150GT

[90 stratos]

First time poster

I Need help with my johnson 150 It is a 1990
First a little history 3 or 4 years ago I was running down the river and It just died when I turned around it was steaming I had picked up a garbage bag and didn't know it (didn't watch water gauge) So I let it cool and fired it back up and it ran fine the rest of the season. well that fall I got the bug and desided to tar it down and rebuild it (myself) I really don't know anything about outboards but I can rebuild 4 stoke autos with my eyes close. well I started reading and asking questions and went at it I had the block check and it only needed to be honed 2ths to true up the cylinder and the piston look really good from what the shop that I was working with said. so I cleaned them and ringed them and put it back together. I had the local shop check ever thing out and fire it for me and they said compresstion was great and timing was only 2 off they said I did and great job and It was put together right.well I ran it for a few seasons and last spring things were a little funny it wasn't starting right it would run down two batters before it would fire and when it would fire it would idle fine and at slow speeds it would be fine. but tring to take off all It will do it about 2800rpms and nothing else.no power under load....I was told that there is a rev limiter on this motor and one shop pulled the wires and that didn't help at all. I am at a loss I can build it but testing it is something else. Any one have any Ideas??? this thing would run my bass boat 57-60 MPR at 5700 with a jackplate on flat water and miss that. Right now It has been sitting in the yard and the weeds are growing around it and I would like to get running so I can sell it or use it. I would be open to anyones ideas.

Thanks
90 stratos

 

[tashasdaddy]

Re: no power to my 90 150GT

check compression and spark on all cylinders is the first step. if will need a carb cleaning after sitting so long, and an impeller, once running again. check your timing. you have fixed jet carbs so no adjusting. here some good info http://forums.iboats.com/showthread.php?t=299680

http://forums.iboats.com/showthread.php?t=228183

 

[90 stratos]

Re: no power to my 90 150GT

Tashasdaddy,

Thanks for the reply I just have a few questions. One being why do I need to go though the carb when I store this boat for the winter (michigan) I always drain the carbs of all fuel.And what do you mean by fixed jet carbs, when I rebuilt the motor I had to buy new metal bowls for all the carbs and when I rebuilt them I had set every thing by the carb gauges (can think of the word )

I understand the compression test, It would tell me if I have a bad ring or bad scored walls Right? And I also understand the spark test.
Question what is a good compression for a rebuilt motor?
And could the timing base be bad?
Not to sure how this thing sparks I'm use to a motor with a distreb, and not a 2cyc.
I will have time by this week end to start working on this but If there is anything else that i should check Please let me know and I can do it all at once.
Thanks
90 stratos

 

[jonesg]

Re: no power to my 90 150GT

compression should be close across the board, actual numbers aren't as important as equal numbers. There are no numbers given in the factory manual, mine are around 85psi and equal. Within 10psi is good.

spark should jump 7/16th inch gap or the ignition is a problem.

carbs usually need rebuilding after sitting idle and it sounds like thats your symptom anyway, not getting fuel beyond idle.
You could try pumping the fuel bulb, if that helps then the pump is suspect.

If pushing the ignition key in helps the boat take off then the pump is good but the carbs need rebuilding.

 

[tashasdaddy]

Re: no power to my 90 150GT

did you do a link n sinc after the rebuild. this coordinates, the carbs and the spark, so they work together, at the proper time.

 

[90 stratos]

Re: no power to my 90 150GT

Tashasdaddy

I did not but the shop that started it did, the first two season it ran great alittle to much power It would blow out of the hole if I wasn't carefull. And this started just like over night.

90 stratos

 

[90 stratos]

Re: no power to my 90 150GT

well the season ended like this, I ran great one day and the next day it all fell apart.I had took them apart last fall and they looked good no build up and very clean, so I really question the carbs at all, unless I have missed something. Is it possible that the timing and the sinc be wacked out?
90 strstos

 

[jonesg]

Re: no power to my 90 150GT

it depends what you mean by 'cleaned the carbs', did you run wire through the jets? use rebuild kits?

linc/sync is important,
Take a look at this,

http://bbcboards.zeroforum.com/zerothread/357667-throttle-roller-timing-arm-adjustment-60-motors

 

[90 stratos]

Re: no power to my 90 150GT

Jonesg
Well when I rebuilt them with the motor rebuild I put new bowl and carb kits and jets all carbs ,Ran it for two season end of last year and shut it down.Drained the carbs (like I always do) then took them off and tore them down and checked them out, so If your asking if I rebuilt them from there with another carb kit no I didn't and I did not run any wire in the jets.I checked the seats and floats (NEW) and made sure there wasn't anything in the bottom.I would think If there was something in the jet it wouldn't cause this much power loss.Or am I wrong.

Thanks
90 strotos

 

[wwcj101]

Re: no power to my 90 150GT

i know this is basic but check and make sure that ol dirt dobber didnt make em a nest in the fuel tank vent

 

[90 stratos]

Re: no power to my 90 150GT

ok guys I went ahead and did a conpression test dry 90 on all and wet 101 -102 on all.Forgot to do a spark test I guess I will have to do that tomorrow.
Any Ideas?

Stratos

 

[emdsapmgr]

Re: no power to my 90 150GT

Your GT model should have the 35 amp alternator. This model has the SLOW system standard. Is this system still disconnected, or was it reconnected? When the engine senses an overheat (203 degrees,) the power pack limits engine rpm to approximately 2500. You need to determine if one side of the engine is actually overheating. If not, you may have a defective head sensor that may be sending a bad signal to the pack regarding an overheat. Have you checked all 6 plug wires with an inductive timing light to insure they are all firing normally when the engine is in the water and under load? Your compression is fine. The concern with the carbs is that some small debris may have gotten into one of the high speed jets, restricting fuel flow. This needs to be verfied, as any fuel restriction will also reduce fuel and lubricating oil to that cylinder. Not only will it not run full rpm's, but you can damage the powerhead.

 

[90 stratos]

Re: no power to my 90 150GT

emdsapmgr

Is this what they call a rev sensor , because thats what it's doing.
I had not replaced it when I over heated it, and rebuilt the motor eather. what I do have disconnected it the sensers on the drivers bank next to the t-stats it seemed to work for a while then now just dosn't help at all.
I have not checked the wires or the firing underload.But the local shop did the timing and it was on.but it run great when it's not under load.
Another thing would this cause it not to start or start hard, I use to be able to start it right up warm or cold but now cold I can run down two full charger batterys before it fires.Thats why I thought timing basic or am I wrong?

Thanks
I will do more testing over the weekend if the rain holds off.
90 stratos

 

[jonesg]

Re: no power to my 90 150GT

If you keep cranking it like this you'll burn the starter up too.

I have a hunch its not getting a healthy spark,

getting it diagnosed is simple enough, compression is fine,

but I don't see that you have done a decent spark gap test yet or tried the timing light under load.

If it passes both the compression and spark test but will not fire try spraying a bit of premixed fuel into the carb throats, it cannot not fire and that must indicate the carbs again.

Its often said and proven out that you must run thin wire thru the jets to verify there is nothing in them.

 

[90 stratos]

Re: no power to my 90 150GT

JonesG
ya I know it's hard on the stator I let it cool down between starts and only let it roll for 20-30 sec at a time so it dose not really heat up.
My plain are to try a spark test over the weekend and see what that will turn up.

Not to sure how to do a timing test under load? What bank is number one plug on?
I also am plaining to pull the carbs and clean them and see if the or a jet is pluged.

Thanks
90 stratos

 

[jonesg]

Re: no power to my 90 150GT

your local shop said the timing was good , but you might want to test it on the water under load, just clip the timing light on the plug wires and see if it drops the spark under load....and when its warmed up.

My engine is a 1991 optical ignition, different proceedure to yours I think.

Get the factory manual, it would be money well spent.

 

[90 stratos]

Re: no power to my 90 150GT

jonesG

Ok here is go's

I did a spark test and this is what happened ..
drivers bank top plug blue /org spark
2nd plug down no spark
3rd plug down no spark

pass bank 1st plug down blue/org spark
2nd plug down no spark
3rd plug down blue org spark

any ideas????
I kinda an at a loss from here..
thanks
90 stratos

 

[billy4hp]

Re: no power to my 90 150GT

jonesG

Ok here is go's

I did a spark test and this is what happened ..
drivers bank top plug blue /org spark
2nd plug down no spark
3rd plug down no spark

pass bank 1st plug down blue/org spark
2nd plug down no spark
3rd plug down blue org spark

any ideas????
I kinda an at a loss from here..
thanks
90 stratos

So there is clearly an ignition system problem, most likely a power pak... An OEM shop manual will have the proper trouble shooting procedure so you can figure it out... Or see if you can borrow one from your local repair shop... Skip getting a Seloc manual...

Good luck....

 

[emdsapmgr]

Re: no power to my 90 150GT

Agree on the factory manual. Read through the ignition section and see if you have the tools and talent to trouble shoot that system. If not, see a factory dealer that has the tools to troubleshoot it and access to parts.