1994 johnson crossflow 90 hp problems with mid range speeds

L

Lewimars

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Hello, i have a 1994 johnson 90hp crossflow, fresh rebuild, starts fine and idles well also has great wot, but when i have to throttle down for no wake areas it shakes and acts like its missing badly, checked static timing and was set at 24 deg btdc wot and showed 4 at idle, changed plugs and stll have the same problem, so far only 10 hrs of run time on it
any ideas i haven't thought of??
 
E

emdsapmgr

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Re: 1994 johnson crossflow 90 hp problems with mid range speeds

You may have a carb issue. Possible you have some minor debris/restriction in the mid jets. Did you overhaul the carbs during the rebuild-pull the mids out and visually inspect them? Did you do a sync and link after overhaul also? Your timing sounds pretty normal.
 
L

Lewimars

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Re: 1994 johnson crossflow 90 hp problems with mid range speeds

rebuilt carbs prior to trashing cyl 1 and 3 yes they are linked and synced, also noticed the plugs are wet/oily, thought it was from the double oil i'm using during break in 25:1, also was bored .020 over stock, should i try the 1 5/16 throat carbs, it has 1 3/16 on it now
maybe i need to open the carbs again, didn't have this problem before, its just really frustrating going slow and running rough, makes me want to go fast in the no wake zones, could it be getting to much fuel?
 
Bob_VT

Bob_VT

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Re: 1994 johnson crossflow 90 hp problems with mid range speeds

Darn near a common crossflow symptom......... the slow (no wake) speed usually results in a sudden occasional stutter...... almost a miss.
 
L

Lewimars

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Re: 1994 johnson crossflow 90 hp problems with mid range speeds

Bob, i would be fine if it was an occational stutter, but it's from 1500-2500 and shakes like the dickens, once beyond that runs like a scalded dog
 
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emdsapmgr

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Re: 1994 johnson crossflow 90 hp problems with mid range speeds

When the engine is shaking at the 1500-2500 rpm range, try choking the engine and see what happens.
 
L

Lewimars

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Re: 1994 johnson crossflow 90 hp problems with mid range speeds

will do, it won't be for a week thanks to Emily's visit,i will let you know.
 
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