1997 200hp ocean runner

[Danobear]

I need help bad.
This engine has had a low speed miss & been a real pain to find. & smokes
Here is what Ive done
1. compresion is 95lbs on all six
2.new stator
3.all 6 carbs rebuilt with OMC. kits & cleaned & set up with the OMC manual
4.new VRO pump
5.carbs sync. inital 5 turns from the bottom all plates closed & open up at the same time.
6. gas is good
7. New t - stats & seats
8.recirculation valves are ok.

I can get it to idle pretty good but the minuite I accelerate with it in the test tank it starts missing & smokes. I checked the timing & it climbs up the scale when I accelerate it was up to 18 deg. & is about 2 at idle

Any help is much appreciated

 

[Dhadley]

Re: 1997 200hp ocean runner

What spark plugs are you using?

 

[Dhadley]

Re: 1997 200hp ocean runner

BTW -- just to avoid confusion, that motor doesn't have a VRO pump. It has an OMS pump. That pump supplys a fairly steady 50:1 all the time. Not a big deal but it may save confusion if you ever need to buy parts for it.

 

[seahorse5]

Re: 1997 200hp ocean runner

Double check everything again. That motor should idle correctly when the timing is about 4° ATDC, not 2° BTDC.

Most of those motors need the idle screws about 6 turns open.

 

[Danobear]

Re: 1997 200hp ocean runner

The plugs are Champion 5939 Ql78yc gaped @ .040 I just picked up a new set tonight. The old one are just a couple months old & have had about 120gal ran through them they are wet on all the plugs. The carbs have 65D's for jets

I will go check the the lync & sync again I am still waiting for the piston stop tool to arive so I can check the timing pointer I havnt changed the timing adj. yet. The eng. used to run great when it was throttled up it just missed at low RPMs

I am a truck mechanic by trade & the outboard is a little new to me but I dont want to give up.
Thanks Dan

 

[seahorse5]

Re: 1997 200hp ocean runner

The plugs are Champion 5939 Ql78yc gaped @ .040 I just picked up a new set tonight.

The factory recommended gap is .030"

 

[Danobear]

Re: 1997 200hp ocean runner

Update
1. plugs gapped at .30 ql78yc
2. still miss's & smokes even when throttle is opened up
3.Timing is 2 deg. after at idle jumps up to 18 after when throtled up
4 took all coils off cleaned grounds & all conections checked ohms OK
5. ran on 50.1 mixed gas eliminated the VRO unpluged it & ran a line from a small can of 50.1 mix
6.indexed the flywheel on tdc on all cyls. marked them 1,2,3,4,5,6 put a timing lite on each cly. & it coresponded with the timing mark


Tonight I put each cyl. on tdc. & had all the plugs out & set my air comp reg. to 40lbs & did a leak down test.
# 3 cyl.is leaking air out # 5 & 1 & # 4 is leaking out #2 & 6 not alot but you can here it none off the others will do this they all hold air.

Thanks for the help