1976 Mercury 650- Bogs Down a little

[tallcanadian]

So I took this outboard for a run this past weekend. This is the first time I've had this on a run since the three years I've owned it. A few weeks I removed the carbs, cleaned them, replaced gaskets, needle a seats, and reinstalled them. I put it on muffs and gave it a Sea Foam treatment. I let it sit for a week and re fired it on the muffs. The motor starts right up with no problem, always did. My compression numbers went up, 115 being the lowest reading of the three cylinders. Installed new plugs. I replaced every rubber fuel line from gas tank to carbs. Fresh gas was used as well.

Monday I brought it to the lake. It fires right up as usual. I let it warm up and for the first half hour only ran it at low rpm, just to get the oil flowing. Anyway I decided on leaving the bay i was in and run it. I don't have a tach so I don't know numbers. I reach a certain point as it was going on plane and it bogged down a little. I didn't do anything and it quit. I turned the key and it fired right up. I was getting on plane again and it started to bog down again but this I kept pushing the gas and it smoothed out and ran like a champ. I have no issue at top speed or low end speed. It's that one spot in between that it doesn't like.

Does anyone have any ideas what the issue could be. Thanks for any input.

 

[tallcanadian]

I'm not sure if this is a bad thing or not if no one replies. lol. Any suggestions at all? I was thinking fuel pump but would expect it to be like that all the time, not just a certain rpm's.

 

[merc850]

Are the low speed needles adjusted for near mid-range smoothness ie. @ 1300rpm 1 1/4 turns in or out. Warm up the engine and turn them in and out slowly until engine is smooth.

 

[quicktach]

gas filters clean?

 

[tallcanadian]

I did adjust the carbs but I have no tach, so I don't know what rpm It idles. Everything is clean. All new lines, hoses, etc.

 

[tallcanadian]

Update. The motor works fine. It still has this what I call a flat spot. I can either slow down a bit or go faster to get by it. It's a strange thing.