Missing part, does it matter?

metriccrescentwrench

metriccrescentwrench

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I think I'm getting near the end of my headaches with my jury-rigged ebay engine (1990 Johnson 200). One of the things that's not on the engine is the idle timing stop bracket and screw, but is that really going to matter enough to justify pulling the flywheel again and installing one? I'm able to set idle timing with the spark advance knob on the linkage, or am I misisng something?
 
DargelJohn

DargelJohn

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Re: Missing part, does it matter?

Somewhere on the linkage will be a throttle stop adjustment. That is critical so your carb butterfly valves open fully; part of the lync-n-sync adjustments.
 
metriccrescentwrench

metriccrescentwrench

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Re: Missing part, does it matter?

I'm not talking about the throttle stop, that and everything associate with the link-n-sync are fine.

In addition to the stop for maximum timing advance there's supposed to be a stop for idle timing near the port side of the timer base. That's what's missing.
 
DargelJohn

DargelJohn

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Re: Missing part, does it matter?

I would not be concerned about a stop for idle timing.
 
Joe Reeves

Joe Reeves

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Re: Missing part, does it matter?

If you're speaking of the full spark advance stop screw that has a rubber cap on one end, yes, it absolutely is an essential part that has to be there. To leave it missing enables the engine to exceed its spark advance stopping point..... pre-ignition will take place, pistons will melt etc.
 
metriccrescentwrench

metriccrescentwrench

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Re: Missing part, does it matter?

Joe Reeves said:
If you're speaking of the full spark advance stop screw that has a rubber cap on one end, yes, it absolutely is an essential part that has to be there. To leave it missing enables the engine to exceed its spark advance stopping point..... pre-ignition will take place, pistons will melt etc.
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NO, not that one, that's present and accounted for.

Both my OMC manual and the online parts diagram shows a stop for idle timing, but I'm kind of not seeing where it's a big deal so long as I can get the idle timing I need by adjusting the knurled knob on the linkage.
 
Joe Reeves

Joe Reeves

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Re: Missing part, does it matter?

Okay, I know of what you speak. I've been retired for a number of years so my memory may be somewhat flawed BUT pulling on memory it runs in my mind that the missing linkage is needed to make absolutely sure that the idle timing does not accidently retard any further than the specified setting..... possible if the idle rpm is changed for any reason. That linkage is there for a reason, frankly I'd go to the trouble to install it if for no other reason to have the engine restored to its original form.
 
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