MercBlack Max "hesitates?"

[lovemylake]

I have owned 2 Black Max Mercs. 175 and 135 hp. Both 1986 models. The 175 was owned for maybe 5 years trouble free. The 135 was purchased this spring & run may 6 hours so far.
Both run great but each seem to have times when they are sluggish to accelerate from low speed. Bog down if you will! Sputter then go! No backfire or anything just kinda sound like it might stall then Wham! she takes off.
Any thoughts? Thanks

 

[coolguy147]

Re: MercBlack Max "hesitates?"

fuel pump?

 

[j_martin]

Re: MercBlack Max "hesitates?"

Do you gas them both from the same source?

 

[lovemylake]

Re: MercBlack Max "hesitates?"

No not the same gas source. These motors were owned at 2 seperate times.
Dont suspect fuel pump because both always start well & generally run great, just sluggish (sometimes) to take off. This usually is after several minutes near idle.

 

[wtxmale]

Re: MercBlack Max "hesitates?"

if you find the problem please let me know,,,i have same problem with 99 200 optimax...i have posted three times with no responses,,,glad your getting some response!!i have replace throttle position sensor,,fuel lines,,bulb,,plugs,,checked with no faults on computer diag, changed fuel,,,next i will change both fuel and air injectors on one cilinder that had darker plug than the rest,,,may be too rich.....good luck!

 

[wtxmale]

Re: MercBlack Max "hesitates?"

one other thing to add to the people who respond to help on this forum,,thankyou,,i was refered to this site by a good friend he told me to be sure i mentioned that i was a disabled vet,,,he said i would get better response,,,well i didn't feel it was necessary to post that info,,,guess i shoud have maybe i would of gotten a response...

 

[j_martin]

Re: MercBlack Max "hesitates?"

Other than the usual dirty spark plugs, carboned up exhaust, etc, an otherwise normally running V6 that hesitates on acceleration would have one of 2 defects.

Decarbon procedure:
http://http://forums.iboats.com/showthread.php?t=158076

1. Partially plugged idle jets/misadjusted idle mixture screws.
2. Linkage misadjusted, usually throttle valves out of sync, or throttle pickup too early. See your manufacturers maintainance manual for procedure.

hope it helps
John