1970 merc 7.5hp....fires but snort wheez

[roonie]

I bought this little gem used but its litterally like in new cond. The coils/stator were fried so i bought another used engine and its all been changed over. I have plenty of spark...i have tons of compression ...both at 110. New gas. Its been running...but barely running.... and she will not idle. Surprisingly...when i start her in reverse or forward gear, she takes right off and revs high as im able to turn the throttle way up in these gears but Neutral locks the throttle. I cannot run her long in gear as i quickly run out of water as im only running in a 7gal bucket.
When i choke her she snorts wheezes and water from the bucket spills all over. Ive taken the carb off ...its clean as a whistle...the whole engine is like new inside and out. I did blow the carb jets out with air while the carb was removed. Made no difference. Brand new spark plugs part #BUHW2. im at a loss here folks. Any help would be greatly appreciated. thanks

 

[roonie]

bumping this up.....trying to figure out why its so inactive on this board....are mercs that reliable...lol

 

[flyingscott]

Adjust the carb could be something that simple and get a bigger bucket you will need to get the motor at least a little warm for that

 

[corm]

It sounds to me like it is not running on the idle circuit of the carb. So either your idle screw is way to lean or the circuit is plugged. The idle needle should be out about 1 1/2 turns from a lightly seated position. Double check the point settings, .020 thous and it should be good to go. I always liked to run a gaped plug like a L77J4C or B9HS-10 gaped at .040. The motors trolled better with them rather than the surface gaped plugs imo. I would not buy new plugs, yours are fine for general usage.

 

[merc850]

The motor should not rev high in N there's a stop for that, it sounds like the shift is out of synch. Set the low speed with the motor running in water in forward.