2.0L Mercury Boggs,spits,coughs Midrange- High range good Idle good

[wpeterb]

1996 150 HP 2.0L150XL Mercury Outboard Serial NO: OG351720
Model NO: 1150422SD
Recently purchased rebuilt by Blackbird (http://1outboard.com/)
a cash only business in Pennsylvania.
Symptoms were good idle, good high rpm, spitting and coughing at midrange. after investigation of the power head the power packs needed to be replaced, the carburetors were found to be incorrect. The carbs were for a 135. I have been trying to get more information about this hybridized motor. I could badmouth this rebuild but after I read about the mods done at Scream and Fly I can imagine what someone may have done to this motor before it got to the rebuilder.
To date the stator, coil packs and carbs have been gone over. Carbs are WM-2A, I was looking for WMM-2 or -2A(stock 150XL carbs). At this point I contacted the Mercury tech support line. They got back to me and said the carbs could work with my application if I jetted them correctly. I have read hundreds of threads in the Scream and Fly forum. There is a considerable amount of references to checking the stator's high range and changing or having the correct "Tuner". I do not know how to check the Stator for high range. I have figured out the "Tuner" is similar to the expansion chamber in a 2 stroke exhaust pipe.
In snowmobiles they are very important.
I have ordered new jets, bleed system hose and some of the bleed system check valves.

If there is a problem with a Bleed System check valve would that cause spitting and coughing at midrange? As I understand the bleed system maintains pressures to the reed block and the carbs.
Could I have bad New Coil Packs? Could I have bad stator?
Could I have bad trigger? Could a bleed check valve or valves cause this? Could the wrong Tuner cause this.
Can you give me an opinion as to one of these being a singular cause?
I have more than $5,000 into this beast with the
Marina and purchase and i think I should be close to
figuring this out.

Thanks

[Mark]

Hi, sorry I can't help you out here but I have an original motor the same as yours that is untuched from new apart from removing the oil injection and going to premix.

Mine was manufactured late 2005 and is of serial number OG167001 and from the merc parts site is apparently a model number 7150422DD.

Id like to hear how you get on for just personal interest and also if I can help by looking at my mariner/merc for details are only to happy to help.

I also have the merc manual. Whats your email address if you want to discuss further??

Cheers Mark

[Rickracer]

If you do a search on Blackbird, you'll see that their reputation prededes them. Here is one: http://forums.screamandfly.com/forum...ight=Blackbird , and here is another: http://forums.screamandfly.com/forum...ight=Blackbird . You can judge for yourself if this is a person you wish to do business with. On your motor, just keep posting info as you find it, and you'll get to the bottom of your problems eventually.