89 150 johnson time seems strange

[steamboatwilly]

Hello everybody,I bought this motor when it had 10 or11 hours on it in 1990.It ran 73 mph then and still does,but i got a gps this spring,found out it only goes 60-61.I started working on it.only gets 5000rpm regardless of what i do to it.Ive cleaned the carbs twice.My question is;I used a spark tester with plugs out,tyed spark advance to the stop,turned over with starter,with timinglight#1plug fires at 28btdc, #2 at 44btdc,#4 at 34btdc.It has good spark on all.Is this normal ?It has not over 100-110 total hours.I run it monthly just not long at a time.It has a five second holeshot.It really runs strong,just not enough rpm and that timing really puzzles me.If anybody has anything I sure would be gratful.I am anyway.Thanks for letting me be on this great site,Love you all.

 

[Joe Reeves]

Re: 89 150 johnson time seems strange

Checking the timing in that manner (cranking speed) the timing should read 4° below what the timing should actually be.<br /><br />Is the full spark advance timing of your engine supposed to be 32°?<br /><br />The reading on your timing light should be the identical or extremely close between #1 and #2 cylinder (#1 = top starboard), (#2 = top port).<br /><br />Are you sure you're obtaining a reading of 44° on that #2 cylinder?

 

[steamboatwilly]

Re: 89 150 johnson time seems strange

Good evening Captain,,,,,Thanks for the answer.The full spark advance is supposed to be 28.I am positive #2 is 44 as I have checked it three or four times,I am busy for a day or two,but I will take it to the lake and get a few rpms.Im afraid to run it very much.I cant be 100% sure,but I believe it has always been like this.By shining a light in spark plug holes,it looks really good,like they are all the same,none are lighter color than others.Could it be maybe a timer-base.The tach.and speedo are exactly the same as when new.It seems to run perfect.If it has a miss or knocks you just cant determine its there.Thanks a lot.

 

[steamboatwilly]

Re: 89 150 johnson time seems strange

This motor is on a Venture 18ft.It has a 24Raker.I took it to the lake today,warmed it up,left fastened to trailer,in farward gear.I reved it to 3000rpm,#1 and#2 was exactly the same,20btdc.I decarbed it like somebody said with Seafoam.I then untied it, went out.Im running along with peddle to the metal,trimmed the normal trim.The tack is on 5000,the speedo is on 68,when I trim it down,the the speedo drops 2-3mph but the tack dont drop.Then I trim it up really high(too high)the tack dont move off 5000,BUT, you can hear the motor rpms really climb(like 600 or800 more).I did this 6 or8 times.Theres no doubt about it.The speedo goes wild,75 -77.When I do this,the motor not omly hums,it sings.(Of course,the speedo is way off)I didnt take the gps with me,I would guess gps would say 63-65.The speedo is about 10% off.Im betting its that gouldarned tackometer.Ill order one tonight.Check back in about a week,Ill let it be known what..Im really glad for your help.,,,THANKS.

 

[raven564]

Re: 89 150 johnson time seems strange

When you trim way up, you are likely sucking air in the prop.

 

[steamboatwilly]

Re: 89 150 johnson time seems strange

Thanks ,raven564.