where to start??

lynchburguy2002

Recruit
Joined
Jul 4, 2007
Messages
3
Let me first start by thanking everyone in these forums!! I have learned so much over the past few weeks just scrolling all the other posts.

So here is my problem, I just bought a 1986 Aries 150 (15 foot) bass boat, it came with matching 1986 mercury 90 hp inline six, the boat had been sitting for 4 - 5 years and was in need of a lot of cleaning. so after emptying all the junk and debris, we rebuilt the carbs, replaced the stator and trigger to correct the lack of spark problem. Now she is running great in the yard on the hose but wont run well enough to get on plane at the lake. I have done the link and sync procedure I found on here in the engine forum, and its all timed and has great compression all cylinders are around 122 -125 I believe it is way over propped?? when clening out the boat i removed two 50 pound bags of concrete and a large chunk of steel from the bow storage area! I'm guessing this was used to counterbalance the boat and assist in leveling it out when trying to get on plane? I have removed the 3 blade stainless prop and can find no markings on the hub or blades. I have no idea what my rpm's would be at WOT because I cant get her to wind up on the lake! so where do I start? should I put all the extra weight back in the boat and see what I get or could someone give me a starting point? what size prop would i need for a 750 pound 15 foot bass boat with a 90 hp inline 6?
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: where to start??

Your boat should plane with a 25 hp.It isn't likely over propped.My first guess is no spark on one or more cylinders.Next guess is one or more carbs not delivering enough fuel.Classic problem when a boat has sat for a long time.
Did you check all passages and jets are clear and prove it?
You may want to carefully squirt a little fuel mix into the carbs to see what happens.Check the fuel pump.
 

lynchburguy2002

Recruit
Joined
Jul 4, 2007
Messages
3
Re: where to start??

well, the carbs were cleaned, soaked and rebuilt. Blew out all orfaces (spelling) with compressed air and then flushed with spray cleaner to check flow.... took boat out yesterday and got her to plane! had the girlfriend at the wheel and I sat in the front seat near the trolling motor. she came up a little slow and then dropped down and was running fine. Maybe a bit lean at top end? will re adjust needles when the ramp isnt so busy! So should I just add the weight back to the front or maybe pick up a 17 or 18 pitch prop and go from there? the tach was bouncing around so I am not sure of actual rpm but it was in the 4000- 4300 range
 
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