1999 200hp merc carb rebuild?

[On The Edge]

Ok pulling the carbs off the old 200hp merc for a rebuild. Started running a little ratty end of last year so i figure it is time for a rebuild and clean. 1st time i have done these carbs, but i have done others. Anyhing i should look out for, or do ,or not do.. Any old Merc heads out there. All Pointers or advice welcome. Looks pretty strait foward

[jawz12]

it's a pretty straight forward job...dumb question...did you perform any type of diagnosis ??? did you check the ignition system voltage ??? you state "running a little ratty"...

[On The Edge]

Ya Everything checks out including all new filters. When i say ratty i mean the A typical E10 fuel crap, it runs but just not like it should. I kinda figured this was going to happen.
The boat holds 90 gallons and was full when winterized in the fall of 07. I only used 24 gallons all last year (sprind of 08) and it was topped off again after that use. All of The fuel has been stabilized but more then half of it is a year and a half old.
I noticed it was running a little ratty this fall. Before i winterized it i pumped out about 40 gallons of fuel and then topped it off with some fresh fuel and restabilized, changed the filters and lower end oil. I then took it up to the local fresh water lake and ran it around the lake for half an hour or so. It just didnt run as smooth as it should..

I figure 10 years old and 700 hrs on the carbs with out so much as even a cleaning and with the E10 it can't hurt to pull the carbs and do a quick rebuild. Besides i got the Kits at cost.. For well under a 100 bucks it's worth my time..

[jawz12]

Ya Everything checks out including all new filters. When i say ratty i mean the A typical E10 fuel crap, it runs but just not like it should. I kinda figured this was going to happen.
The boat holds 90 gallons and was full when winterized in the fall of 07. I only used 24 gallons all last year (sprind of 08) and it was topped off again after that use. All of The fuel has been stabilized but more then half of it is a year and a half old.
I noticed it was running a little ratty this fall. Before i winterized it i pumped out about 40 gallons of fuel and then topped it off with some fresh fuel and restabilized, changed the filters and lower end oil. I then took it up to the local fresh water lake and ran it around the lake for half an hour or so. It just didnt run as smooth as it should..

I figure 10 years old and 700 hrs on the carbs with out so much as even a cleaning and with the E10 it can't hurt to pull the carbs and do a quick rebuild. Besides i got the Kits at cost.. For well under a 100 bucks it's worth my time..

the early mercs,like that one,were famous for having problems in the cdm's...that's why it's real important a few diagnostic steps are taken,before parts are thrown at an engine...
e-10 fuel...i hear this all the time...it's bullshit !! i have ran into 3 boats that had problems with fuel,that was when the e-10 fuel was interduced,these 3 boats,all got fuel within days of each other from the same fuel dock-that's the only problems i've seen...other guys i know in the buisness have seen the same thing as i...do not be so qucik to blame the fuel

i know in hot humid aareas,like southern florida,there's some problems-ted,qquest sport fishing,can attest to that,but in our area,i've seen none...
if you're got a phase seperation,it's usually caused by the fuel system in the boat,bad o ring on the fuel fill,problem in the vent,or,the tank itself...guys like bill at starbrite are buying porsches from selling startron to people,for nothing...i hear owners telling other owners to add water zorb and all kinds of stuff to fuel tanks-most of these products are alcohol based,did you know that ??? same stuff that's added to the fuel-funny stuff huh ???
listen,if i were you,no offense,i would do a little further testing on that engine before i started pulling carbs off-granted,it's not brain surgurey,but,no offense,if you've gotta ask about this job on a web site,than mabey you should reconsider...

[On The Edge]

Thanks for the input great info and i will certainly look into what you sugest. That said with all due respect i have had just the opposite first hand experience with E10 fuel and have had E10 gas go bad in 12 months of sitting to the point of last spring my bass boat would not run on it. I Drained and refilled the fuel tank including the fuel lines filter and even the bowl on the carb and the motor would still not run. I Pulled the carb, dissasembled and soaked it, Cleaned, reassembled, and reinstalled and it she purred like a kitten. I have had the same situation with my old 4 wheeler and my lawn tractor..

Also so there is no missunderstanding i was not asking how to do the job, just looking for any advice that may save me time or aggrivation doing it. Little things that may be specific to those carbs from someone who has done the job. You know like the be sure to do this or Do not do that, I used this cleaning product, or you will need this special tool, That kind of stuff.

I made the same kind of post last spring when i suspected i needed to replace the popit valve on the same motor and got some good advice. Sounded, looked like, and was an easy enough job, just nice to get some input from someone who might have done it.

Again i will definately look into what you sugest. Thanks for the input..

[Fortunamate]

just as a mechanic who reads alot i would suggest getting a feul water separator as becuase the new fuel will work much better with one and yes the e-10 will change engine performance because the ethanol in it will clean yes i said clean all the hoses it travels through gunking up the jets and diaphram of the carborator and just make sure the diaphram isnt cracked or really stiff and make sure all the jets are cleaned and finaly make sure the float and the bowl are spic and span.
classic example of why water fuel separators are necessary is when you take your bowl off and there is fluid that doesnt look like gas or looks like oil on water it is water will sink to the bottom while the fuel sits on top and gets picked up by the jet and away she goes eventually water will build up and the engine will run ratty beacuase the water and fuel are both getting picked up
thats just my 2 cents
-Cam

[On The Edge]

Cam thanks for the input Good advise for everyone. Boat has had a water separator filter since new. A New filter gets installed every year somtimes twice depending on the amount of use and i keep a spare onboard just in case. All filters were changed when i winterized and will get changed again after the first coupple of uses. Carbs will be comming off today one at a time for a cleaning inspection and rebuild.. Along with checking what Jaws recomends..

[Fortunamate]

your welcome and if you have anymore questions i am reading about your carbs as i type this so feel free to ask

[cpmarine]

If it's a carb you could check by pulling plug wires making sure each cylinder drops, then spraying gas into the throat of the carb for the cylinder that didn't drop to see if it picks up. Each carb barrel does one cylinder so if you haven't lost a cylinder it probably isn't a carb.

[On The Edge]

Splashed the proline today for the shakedown cruse in the local lake. After cutting of fthe shrink wrap. I had a few things to take care of. I pulled the carbs a few weeks ago for a rebuild and cleaning. Crabs were pretty clean but now they are spotless. I had put the carbs back on last week but needed to reconnect the fuel lines and put the airbox back on.

Got everything connected put the batteries in, turned on the battery switch, put on the muff, turned on the water, hit the key and all i got was the starter spinning. Bendix would not inguage the flywheel. Ok time for a bit of trouble shooting. Pulled the gear and spring off the starter to check for corrosion all looked good cleaned and lubed it up reinstalled it and tried the key again same thing. Ok time to check all the wireing.

Started at the batteries because it was the easiest. Pulled the terminals one at a time cleaned and reconnected. Ok lets try that. Turned the water back on again hit the key. BINGO. Problem solved bad connection.

Now lets see if she will start. Hit the choke and turned the key. The mortor turned about 6 times and fired. Big fog of blue smoke from the fogging oil and few sputters and then it smoothed out. After about 30 seconds of running i noticed it was ideling high, around 1100rpm's Well thats not right.. Shut her down pulled the airbox and refired it. Still ideling high. Checked in the carb throats all looked clear. Looks like i need to consult the service manual. Carbs need to be resynched and throttle needs to be adjusted. Followed the prosedure tightend everything down turned on the hose and fired her up.. B I N G O
Perfect idle and super smooth..

Cleand up all my stuff, hooked her up to the truck, Drove up to get hoop, and headed to the lake. Everything went smooth. Dropped it off the trailer and she fired right up. Backed off the ramp and sat at idel while hoop parked the truck. Picked hoop up and headed out across the lake at a conservitive 20mph went about a mile and kicked it up a knotch to her sweet spot 4100RPM and 30mph. Crused about another mile at that speed and figured it was time to stretch he legs. Opened her up to WOT 5600RPM and squeeked out 42MPH, that's the spot right there.

10 year old carbed 200 merc and still running sweet. Cruised around the lake for about 30 mins and headed in. Back at the ramp i figured i would shut her down to see how it would start back up. Snap of the key and it's all good.

Put her back on the trailer and headed home. All i need to do is load up the fishing, boating and safety gear and i am ready to GO FISHING..

I had some worries about how she was going to run this season because it was running a little ratty last year when i put it away for the season and the fuel in the tank is about 18 month old. That was the reason for the carb cleaning and rebuild. I did pump out 1/2 of the fuel and it all looked good, no sediment, no water, no discoloration. I still want to Decarb it this week, and run more of the old fuel out on the lake and then top it off and change all the filters again before the first trip to the salt. But i dont expect any problems..