PLEASE someone get me running again...

Dawgs

Petty Officer 2nd Class
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Apr 10, 2008
Messages
159
1987 150 rebuild...motor was running but idles rough...i messed with the timing a little now it wont start at all....just cranking...lets start from scratch...new battery...new fuel...new plugs...where do i begin?
 

Dawgs

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Re: PLEASE someone get me running again...

2 top plugs are black and wet....2 middle plugs are cleaner
 

emoney

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Jul 19, 2010
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Re: PLEASE someone get me running again...

I think you should start at the very, very beginning. Start with a compression check, and then post your results. Next thing would be to do a spark test. You'll find plenty examples in this specific thread for doing that to make sure you're getting good spark to each cylinder. Then, if both of those are good, it's on to the fuel. When you said you"messed with timing a little", was it running good before then?

The more info you can share with the real pros on here, the easier it is for them to help you, and they will and can help you. They'll get you going if you can share as much information as possible. Anything that comes up that's out of the ordinary, remember that pictures tell a thousand words. If compression and spark are good, you can pretty much assume the carbs/fuel system is where the bugs lie because ethanol sure does affect our older outboards. Also, share all the history you can. For instance; "I picked my boat up from a guy last month who had spent quite a bit on the fuel system and then....". Get the feel for what i'm saying?
 

Dawgs

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Re: PLEASE someone get me running again...

ok well i replaced the crankshaft on this motor..rebuilt the carbs...put it back together ..put it on the boat...surprisingly the motor ran...it started but idles rough..popping every now and again...not real loud pops but popping none the less(this is all on muffs in my driveway)....all cylinder get spark...good spark? how do i determine if its a "good enough" spark? i will do a compression test asap...my whole thing is it ran and now it wont start...so i know it runs...
 

Dawgs

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Re: PLEASE someone get me running again...

all i wanna do is get started so i can at least check the timing
 

daselbee

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Re: PLEASE someone get me running again...

all i wanna do is get started so i can at least check the timing

Guess what? Doesn't have to be running to check the timing! Use your noggin. Put a timing light on #1, and crank it at starter speed. It will show you your idle timing. If no spark, no timing light flashes...you got another issue.
 

Dawgs

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Re: PLEASE someone get me running again...

i do have spark..the timing light flashes but i do not know the first thing about using the light...thats why im here asking
 

Dawgs

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Re: PLEASE someone get me running again...

ok i found a new problem..i screwed up...there are 2 types of carb gaskets...one goes between the carbs and intake manifold...the other goes between the carb and silencer base.....i have them switched...can that be causing my problems? will that make it hard to start and idle rough?
 

levi_tsk

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Dec 26, 2010
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Re: PLEASE someone get me running again...

could be ... but did you ever get the timing set?
 

blimp

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Sep 30, 2009
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Re: PLEASE someone get me running again...

yes, that would likely cause an airleak between the carbs and the reeds. swap em back.
 

Dawgs

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Re: PLEASE someone get me running again...

ill swap them back tomorrow....gimme some hope....what is the likelyhood that that is the problem?
 

daselbee

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Re: PLEASE someone get me running again...

i do have spark..the timing light flashes but i do not know the first thing about using the light...thats why im here asking

Examine your flywheel rim. Locate the hash marks that are stamped into the metal rim. You might have two sets of marks, one set for #1 cylinder, one set for #2 cylinder. Take some white fingernail polish and carefully paint the mark that corresponds with the book specified idle timing FOR CYL #1. My idle timing is 5* ATDC (after top dead center). Paint the line for your engine. While you are there, paint the mark for the WOT timing value, mine is 18* BTDC (before top dead center). You will absolutrly see the TDC mark, so one painted line will be on one side of TDC and the other painted line will be on the other side of TDC. You will only paint two of the marks.

Paint the lines FOR YOUR MOTOR. You having an older crossflow, your values will be different than mine.

Now, all plugs out, except #1, clip the timing light pickup over the #1 plug wire, turn key ON, and preferably use a remote starting switch at the solenoid to spin the engine over at a fast starter speed. Point the timing light at the timing pointer, and look on the flywheel as the engine spins for the white marks to show. It is just like a strobe light effect. That bright timing light will flash and hopefully, the idle timing mark will be right in line with the timing pointer. You may have to do this in subdued light, in the garage, or at night to see the white marks.

You can then use Joe Reeves' WOT timing procedure to set the WOT timing. After WOT timing is set, I always verify on the water at 5k rpm. Just to be sure.
 

Dawgs

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159
Re: PLEASE someone get me running again...

in the book all i see it "pick up timing" is that idle timing? i will do all of this tomorrow...lets just say that the idle timing is off....how do i adjust it?

i just assumed it was the timing...maybe its just the gaskets...who knows but ill swap the gaskets and check the timing

dasel thanks for the detailed instructions
 

jbjennings

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Jul 18, 2007
Messages
3,903
Re: PLEASE someone get me running again...

I'm thinking that the motor should be properly timed if the flywheel key on the crank is not sheared. Your timing may not be syncronized to the carbs which is done by adjusting the timing stop screws as far as I know. (Keep in mind, I know absolutely nothing about a 150hp OMC motor) I see your motor has a CD ignition, so I'm unsure what you mean by "messed with the timing". Can you explain what you did?

Either way, I'd check the spark to see if it is actually good enough by getting a $6 spark tester at autozone and seeing if the spark will jump at least a 1/4" air gap with a HOT blue spark. If it does, then you're o.k.

After good spark is verified, go to the fuel system. If you have the wrong gaskets on the carbs, that's definitely something I'd fix first after verifying good spark.
Good luck,
JBJ
 

Dawgs

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Apr 10, 2008
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Re: PLEASE someone get me running again...

what i mean by "messed with the timing"....all i did was adjusted the screws..idle screw and wot screw....so maybe i didnt mess with it at all...
 

jbjennings

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Jul 18, 2007
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3,903
Re: PLEASE someone get me running again...

If all you did was adjust the stop screws, then all you need to do is get them back where they were. You should be able to do it with a timing light as daselbee instructed without it running. You definitely need to get them set back right, the high speed stop in particular. If it's not right, you could get detonation and eat away your piston tops. The Joe Reeves timing method is really handy and is in the "TOP SECRET FILES" thread at that top of this forum.
GOod luck,
JBJ
 

Dawgs

Petty Officer 2nd Class
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Apr 10, 2008
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159
Re: PLEASE someone get me running again...

so is "pick up timing" the same as "idle timing"
 

Solittle

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Apr 28, 2002
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Re: PLEASE someone get me running again...

Read emoney's post then read it again then again. You are scattergunning (guessing) with your posts.
 

Dawgs

Petty Officer 2nd Class
Joined
Apr 10, 2008
Messages
159
Re: PLEASE someone get me running again...

ok tomorrow starts fresh...comp test...spark test..ill correct the gaskets...then post my results
 
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