BUP

iTrader: (9)

Merc TKS (TURN KEY START) 2 bbl carbs came out for model year 2004 (no choke but an electric solenoid persay) . He has the 2 bbl Mercarb with a choke and his motor for 1997 was rated at 210 hp. it was a NON Vortec as fact he has the 210 hp engine . The engine serial # will dictate all of that as he posted. Sorry both Volvo and Merc has these in model year 1997 NON VORTEC motors. Volvo rated theirs at 215 hp. 5 hp more than merc. Both had 2 bbl carbs as Volvo used a 2 bbl Holley

BUP

iTrader: (9)

your problem might be weak or bad battery also bad grounds / possible corrosion issues especially on your battery terminals at both ends. Also could be fuel pressure related - what is it ? Change your fuel water sep filter - as well.

A fully charge battery is 12.7 volts not 12 volts. A battery with 12 Volts is half dead.

Possible weak alternator would be on the list as well along with checking back side orange lead for a good solid connection.

Jonesyfxr

iTrader: (1)

Sounds to me it's a wire on the wrong plug after tuneup. It happens occasionally.

jstand22

Alright some developments....now it won't stay running. It fires up, then dies....I can see the electric choke is staying open at all times. So I have to fix that before I can get back to finding my miss. Anyone have a diagram or procedure for repairing these electric chokes? Is the spring stuck? Do I replace the unit?

Also, all the wires are on correctly. I have checked 6 times now. Pulled all the plugs yesterday too, all normal. Fuel/Water filter new last month, also Fuel Tank is brand new, screen on tank pickup was cleaned too.

BUP, I'm going to have to fix my start issue first (though that shouldn't be a big deal - pretty sure it's that choke), then I'll have to check my alternator leads (battery leads have zero corrosion). I'll clean up the grounds on the back of the motor as well.

BUP, since my plugs all looked pretty good and smelled normal, would you suspect the ICM? Or a possible timing issue? I can tell you that it was running very rich when it was running with the miss.

SB

iTrader: (1)

Electric chokes produce their own heat to open the choke. Did you check the choke when it's stone cold ?

BTW: Even though I haven't serviced a Merc 2bbl, I have heard from many that I help convert to 4bbl's that the 2bbl's aren't the most reliable thing around. Again, no experience, just people chatter.

jstand22

Yeah, the Mercarb doesn't seem to be that great of a carb. Simple, but there seem to be problems. I'd love a nice Edlebrock or Holley...maybe next season. Holley makes a 500 cfm 2-barrell which I believe will bolt right up to my intake...that would be pretty cool. This little boat is already a rocket, I'm sure the extra 30hp or so from the 4bbl would make it even more fun

Back to the problems:
Yes, the choke remained wide open on a stone cold start, even after giving the throttle a pump. I have never seen the choke closed.

SB

iTrader: (1)

Don't waste your money on another 2bbl. Unless cheap and good replacement.

And, no, the Holley will not bolt right up to your intake. Different bolt pattern. Mercarb uses the 'large' Rochester 2bbl pattern. Volvo uses a 4bbl intake manifold with adapter on many of their 2bbl set-ups....so...speaking of which....is why the added HP. Not really the carb, but the manifold that makes the added hp.

jstand22

Poop. Gotcha. I'll have to start saving for an intake an pick a 4 barrel. I'll probably put if off till next year; I spent alot of time and money restoring this boat and want it to work for the rest of the season. I just put in a new fuel tank, sea water impeller, gimbal bearing & bellows, I re-carpeted it, replaced cap rotor wires plugs, replaced starter, replaced the manifolds and risers, rebuilt the engine cover and had new vinyl put on, and I'm sure I'm forgetting more. I've easily spent 120+ hours since April 1st doing all this work, and I'm burnt out.

I got this boat for a steal (the previous owner though the engine was seized....it needed a new starter and some gas!!!! only 232 hours), and I've really brought it back to life.

Carbs are new to me (I'm 26 and the closest thing I've had to a carbed engine was a 1995 GMC 1500 TBI 305, haha), so I'm having trouble trying to figure out if this is carb or ignition related. I appreciated everyone's help on here, it has been helpful. I did a little poking around yesterday, but I'll really dive in during the next few days/weekend.

BUP

iTrader: (9)

There is nothing more wrong with 2 bbl carbs as 4 bbl carbs except for making power. The problems mostly seen with the 2 bbl.'s carbs are the accelerator pump inside its cavity. Stuck, deteriorated, poor seal and so on.

Mercruiser has been using this 2 bbl Mercarb - exact carb exclusively in all apps for small block and down since 1997 till the end of the marine carb era starting 2013. They have not used a 4 bbl carb since the end of 1996 for stock black production engines of all small blocks and down engine sizes.

A stuck open choke IMO is not going to stall your engine - it will make a cold motor very hard to start. If the motor is already warmed up the chock is opened.. Take your inlet fuel line off at the carb and look at the fuel filter screen insde the fitting - is it restricted, next possible issue fuel delivery problem and or carb rebuild required / accelerator pump as it is in the whole carb rebuild kit.

Jonesyfxr

iTrader: (1)

Last year I helped a friend of mine with his 20ft Sunbird. It has a Volvo Penta Vortec 305. The engine had a high rise dual plane intake with a Holley two barrel on it. The boat ran well, but he wanted more. I found him a reman marine 600 cfm vac secondary Holley from Allstate Carbs. It cost much cheaper than a new one and was dead on right out of the box. The boat now flies and he's a happy camper.....just something to think about, if you get a new carb.