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70 Evinrude Linkage Sync

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usm98

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I have a 1975 Evinrude 70 hp 7

I have a 1975 Evinrude 70 hp 70573B I am having trouble getting the syncronization part down the engine runs good at 2800 rpm but seems like the timing is off at higher throttle and only runs at a low ok at lower rpms. Is there a method of adjustment I am missing. I try to follow the OEM manual but...
 
"Sorry Idles rough in order to

"Sorry Idles rough in order to maneuver I have to jockey the throttle, once I get out of the no wake zone and open the throttle all i can get is about 3000 rpms but the engine runs rough and pops a bit, I can throttle back to about 2800 and the engine is smooth and with the occasional hesitation or spit. I have cleaned the carbs til they nearly shine. I believe my next area is the sync and link area I want to get beyond 2800 rpms but don't know what to do."
 
"Have you manually cleaned the

"Have you manually cleaned the high speed jets located in the middle bottom center of the carburetor float chambers? That is, you're absolutely sure that those jets are clean? If not, clean them.

Check that the throttle butterflies open and close all at the same time, and that the butterflies open fully to a horizontal position.

The throttle butterflies should just start to open when the cam scribe mark is dead center with the throttle cam roller. Check it.

Ck compression. What is the reading of all cylinders?

With the s/plugs removed, spark should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Does it?

Does pumping the fuel primer bulb have any effect when this problem arises?

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay store at:

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"
 
Sorry about slow response been

Sorry about slow response been a rough week.
70 hp Evinrude on a 20 ft pontoon.
Idles rough and I have the RPMs a little high so it will run around the launch ramp
On the water I can only get 2800 to 3000 RPMs any more the motor dies back runs rough pops a little until I retartd throttle then it smooths out and runs sweet at 2800 RPMs I do believe the carbs are clean they have been apart at least 4-5 times Compression is in the 120 range with some variation between cyl. Checked spark jumped 7/16" on all three not sure about color was in full daylight and was not sure if the color was blue. Pumping primer bulb has no affect
 
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