Mercury 90 HP Carburetor Sync gauge

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avius

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saumon

saumon

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Re: Mercury 90 HP Carburetor Sync gauge

You don't need that at all.

In an OB, synchronizing the carbs simply means that they open at the same time. Loosen the link rod, so they'll be all closed, and retighten.
 
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avius

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Re: Mercury 90 HP Carburetor Sync gauge

Thanks saumon I'll do that. That seems perfectly logical now that I think about it. But I wonder why the Seloc book adds in the stuff about the motor needing to be under load and using a sync gauge and all that. Is syncing the carbs anything to do with "link & sync?"
 
saumon

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Re: Mercury 90 HP Carburetor Sync gauge

avius said:
Is syncing the carbs anything to do with "link & sync?"
Click to expand...

Yes. Actually, it's the first step of the entire process. After that, you'll adjust the throttle and set the timing.
 
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hondon

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Re: Mercury 90 HP Carburetor Sync gauge

Is this unit a 2 or 4 stroke?
 
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avius

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Re: Mercury 90 HP Carburetor Sync gauge

Would out of sync carbs cause the motor to die when WOT in gear?
Doesnt happen in neutral, but in gear under load it boggs then dies.
 
saumon

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Re: Mercury 90 HP Carburetor Sync gauge

I'm not very familiar with 4-strokes engines but in 2-strokes engines, the first thing i'd look for this particular problem would be the fuel pump diaphragm. As yours is a carbed one, it should have a fuel pump too.
 
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avius

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Re: Mercury 90 HP Carburetor Sync gauge

saumon said:
I'm not very familiar with 4-strokes engines but in 2-strokes engines, the first thing i'd look for this particular problem would be the fuel pump diaphragm. As yours is a carbed one, it should have a fuel pump too.
Click to expand...

Thanks for the advice Sauman. When I took apart the carbs for cleaning I also took apart the fuel pumps (I have two per motor). Aside from a little varnish from the old fuel, they appeared to be okay. Naturally, I cleaned them up. The diaphragm itself was fine, had no tears or holes that I could see. I spoke with the Mercury outboard support guys and they told me that the only way to sync my carbs was to get a hold of a sync gauge set. This is the one I bought online : http://carbtune.com/. Haven't received it yet, but I'll be sure to post the results. HOPEFULLY this fixes my problem! I'll definitely post my findings though so that it may help the next guy that has similar problems.
 
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