Carb rebuild/cleaning

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macowneril2015
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Carb rebuild/cleaning

Post by macowneril2015 »

I was wondering how often everyone cleans their carbs? My boat has been acting up and I am only reaching low end of the top RPM range. Not sure if was worthwhile to pull the boat out to clean/rebuild the carb. The engine sat for 5-10 years without use prior to me getting in the water 3 years ago.
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Tomfoolery
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Re: Carb rebuild/cleaning

Post by Tomfoolery »

Run some Sea Foam through it. Amazing stuff. https://www.seafoamworks.com/

I used it to get my Dad's snowblower running, which hadn't run in 10 years. Got it running smoothly after a while. No carb cleaning or adjustment on my part, other than SF in the tank.
Tom
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opie
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Re: Carb rebuild/cleaning

Post by opie »

About every three years for me. No replacement parts ever needed. ( be careful with gaskets, though) Just patience and a thin wire. I may have pictures somewhere. It can be done in a day or overnight on shop bench. I usually remove whole carb assembly and take it home. Symptoms it needs cleaning is poor idle and poor moderate speed.
adudinsk
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Re: Carb rebuild/cleaning

Post by adudinsk »

Depends on how the engine was cared for.

1) If you use Seafoam all the time, lots of "Spooge" collects as Seafoam contains Alcohol. DO NOT USE IT EVERY TANK!!! (confirmed this with Dyno Lab at one of the Big 3 where I used to work!)
2) Many OBs have a fixed main jet (EPA versions) and you cannot get it out. You can pry out the plug.. and replace it.. not usually needed .. even after 20yrs .. unless your carbs were really abused (or you sunk the OB)

I just redid mine.. Mercury HQ said to do a clean every 3-5 years by taking it all apart.
3) But remember.. you then need to SYNC all your carbs to get them to run smooooooth. DO NOT sync at idle.. as your idle will be smooth.. but higher RPM will not.. typically you should do it in mid RPM band.. so 2500-3000rpm.. Most people do not run wide open all the time. This way if you usually motor at 2500rpm.. its as smooth as possible, and MPG is optimized for that RPM.
(not hard to do .. but you need the gauges.. Just a matter of adjusting idle screws so all vacuum is same on each carb)

4) I replaced everything possible in all my 4. (I posted the damage of running alcohol gas/seafoam.. confirmed it with DYNO as to the residue.. from water/alcohol ..)

Had 2 with 99% plugged jets. (From the white residue)
Had 2 with tons of "spooge" all over the gasket.

Float needle valves were ok.. but did them anyway .. (bought the kit.. why not)
Float itself were fine.

5)Did have to calibrate the float heights.. not hard.. get the $20 carburettor float scale... amazon.. easy to do.. use service manual to get the right height

Rebuild kits from Mercury are about $200us EACH.. Sierra Marine..$100US EACH (for me x 4 carbs) this does NOT include the main needle valve, as most carbs are now sealed in .. and set .. (EPA versions) You can buy them separately and adjust them separately .. about $15 us each.. but usually NOT needed.

Mercury has a GREAT 3 step cleaning process/Set of fuel additives (3 solutions ) that rock .

Hardest part for my OB was removing the Throttle Position sensor.. and throttle linkage without dropping anything into the lake.

Also get a GOOD torque wrench.. you will need on in Inch /lbs.. (1/4" drive) And torque to spec in steps.

Difficulty...
5/10
Time
Removal 1-2 hours if you never did it before.
Clean/Rebuild 30min/carb
Reinstall 1-2 hours taking your time so as not to muck up anything (or pinch a wire behind something)

First time may be "daunting" but 2nd time will be easy and you will not hesitate..

AD

If you take off the intake manifold (I had to) replace the gasket..$15 not worth having to take it all apart later
adudinsk
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Re: Carb rebuild/cleaning

Post by adudinsk »

DO NOT run seafoam every tank.
One use.. ok.. maybe.. if you run out the tank of gas in one day.. so it does not pick up water.

Confirmed this with Dyno Experts at one of the Big Three... they had MANY studies on it for Carb (old studies) and Fuel Injectors.

SeaFoam was initially designed for 2 stroke... OLD engines..
Contains LOTS of Isopropyl Alcohol..(10-20%!!!) and Naphtha (25-35%) the rest is an oil carrier..

Does not do a lot..MUCH better stuff out there..

If you want to use a additive every tank.
Quicksilver Quickare is very good.

Quicksilver QuickKleen is also good.. has more Naphtha.. and similar contents.. different blend.. has several additives.

Quicksilver Quickstor is just a typical stabilizer .. any marine one will do.. although Quickare will keep your fuel fresh for 12 months.. (kerosine based.. 50-60%.. ).. so Quickstor is not really needed if your using Quickare..( but you can)

MSDS SHEETS HERE
-----------------------
MERCURY
http://www.mercurymarine.staging.yartdi ... sheet.aspx

SEAFOAM
https://seafoamworks.com/uploads/2019/0 ... 05-ENG.pdf
(not much in this stuff....)
socalmacer
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Re: Carb rebuild/cleaning

Post by socalmacer »

I have a Honda 50 on my 1996 26X and I just had to rebuild the 3 carbs for the first time since 1996. I did not run the carbs dry after use this entire time. I usually purchased my fuel from Chevron if it makes a difference. I would start with fresh fuel at the beginning of each season but the fuel in the line and carbs would be old. When I rebuilt the carbs I noticed the jets (mains were in better shape) were all clogged and took some soaking in carb cleaner and poking around (the secondary holes are about the diameter of a staple) to unclog. The motor ran like new when finished. Going forward, I now run the carbs dry after each use. As someone that works in the oil business, I would attribute the recent reformulations of gasoline has contributed to this problem.
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Tomfoolery
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Re: Carb rebuild/cleaning

Post by Tomfoolery »

socalmacer wrote: Sat Sep 19, 2020 9:14 am I have a Honda 50 on my 1996 26X and I just had to rebuild the 3 carbs for the first time since 1996. I did not run the carbs dry after use this entire time.
In case you weren’t aware, the BF50’s have carb bowl drains. I run mine dry in the fall, then drain the bowls. There’s even a pair of black hoses that store on the carbs, with access holes in some bit of structure, and you move one of the two hoses to get the last one. Never had a problem starting it in the spring, knock wood. :wink:
Tom
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mallardjusted
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Re: Carb rebuild/cleaning

Post by mallardjusted »

SeaFoam is excellent at cleaning out carbs. I use it, but just at the start of the season. It cleans, but something like Startron or Marine Sta-bil is better for storage and ethanol protection.
adudinsk
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Re: Carb rebuild/cleaning

Post by adudinsk »

Just do not use it every tank.. your just adding alcohol to your gas..


AD
macowneril2015
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Re: Carb rebuild/cleaning

Post by macowneril2015 »

adudinsk wrote: Thu Sep 10, 2020 5:16 am Depends on how the engine was cared for.

1) If you use Seafoam all the time, lots of "Spooge" collects as Seafoam contains Alcohol. DO NOT USE IT EVERY TANK!!! (confirmed this with Dyno Lab at one of the Big 3 where I used to work!)
2) Many OBs have a fixed main jet (EPA versions) and you cannot get it out. You can pry out the plug.. and replace it.. not usually needed .. even after 20yrs .. unless your carbs were really abused (or you sunk the OB)

I just redid mine.. Mercury HQ said to do a clean every 3-5 years by taking it all apart.
3) But remember.. you then need to SYNC all your carbs to get them to run smooooooth. DO NOT sync at idle.. as your idle will be smooth.. but higher RPM will not.. typically you should do it in mid RPM band.. so 2500-3000rpm.. Most people do not run wide open all the time. This way if you usually motor at 2500rpm.. its as smooth as possible, and MPG is optimized for that RPM.
(not hard to do .. but you need the gauges.. Just a matter of adjusting idle screws so all vacuum is same on each carb)

4) I replaced everything possible in all my 4. (I posted the damage of running alcohol gas/seafoam.. confirmed it with DYNO as to the residue.. from water/alcohol ..)

Had 2 with 99% plugged jets. (From the white residue)
Had 2 with tons of "spooge" all over the gasket.

Float needle valves were ok.. but did them anyway .. (bought the kit.. why not)
Float itself were fine.

5)Did have to calibrate the float heights.. not hard.. get the $20 carburettor float scale... amazon.. easy to do.. use service manual to get the right height

Rebuild kits from Mercury are about $200us EACH.. Sierra Marine..$100US EACH (for me x 4 carbs) this does NOT include the main needle valve, as most carbs are now sealed in .. and set .. (EPA versions) You can buy them separately and adjust them separately .. about $15 us each.. but usually NOT needed.

Mercury has a GREAT 3 step cleaning process/Set of fuel additives (3 solutions ) that rock .

Hardest part for my OB was removing the Throttle Position sensor.. and throttle linkage without dropping anything into the lake.

Also get a GOOD torque wrench.. you will need on in Inch /lbs.. (1/4" drive) And torque to spec in steps.

Difficulty...
5/10
Time
Removal 1-2 hours if you never did it before.
Clean/Rebuild 30min/carb
Reinstall 1-2 hours taking your time so as not to muck up anything (or pinch a wire behind something)

First time may be "daunting" but 2nd time will be easy and you will not hesitate..

AD

If you take off the intake manifold (I had to) replace the gasket..$15 not worth having to take it all apart later
How hard is it to resync it all, mine says to adjust ignition and carb sync? that is the part that makes me nervous. I have the service manual but I do not want to kill the engine. I was planning on having a mechanic winterize it, would it make sense to have him do the ignition timing/ carb sync or do you think it would annoy them that I did the rebuild and they have to retime / resync?
adudinsk
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Re: Carb rebuild/cleaning

Post by adudinsk »

To Sync all the carbs is not hard

You must have the correct set of gauges.. ($100 tops)
You connect one gauge's hose to each carb intake (there are little screws you undo.. and thread in the gauge hose)
(Some have 5mm threads.. Yamaha/Merc have 6mm ) Make sure you get a gauge with BOTH 5mm and 6mm threads for the hose adapter

To get best mpg/performance fire up the engine/let it warm up.. then set it to the normal RPMS you usually cruise at.
(you want to tune to THAT RPM as that is what you will mostly run at.)

The gauges will read some vacuum and you want to adjust the carbs so the are all VERY close.
If the gauges flux all around and are not stable.. most gauges have an adjustment (screw.. separate valve..etc..)
Make sure your set has that feature.. some Made in China ones do not.

Adj gauges to they are pretty stable.. using the valve/screw/setting thingie with your gauge set

To adjust the vacuum so each carb is identical (or very close) you play around with the idle screws.
The Service manual will give you "specs" for how close they need it.. but if they are almost all the same your good to go.

Since you tuned for your normal RPM cruise .. that will be the sweet spot.
It "may" idle a bit rough.. but thats ok. (no carbs are perfect).
It should NOT stall at all at idle.
(Check after adjusting that your base idle is to spec.. often printed on the outboard.. somewhere)

You want to get the best MPG/fuel burn/power at the RPM you normally cruise at most of the time.
Tuning is quick.. takes longer to set up.. warm up the OB.

When done, remove hoses from the gauges... (1 per carb)
Reinstall the screws you removed... from the test ports.
(make sure they are air tight.. but not too tight.)
Your done!
I got my gauges from Ebay for about $100 with shipping.
You really notice the difference.. MUCH smoother at target RPM.
(Some ppl do adjust for IDLE.. but unless you "putt" around always.. not optimal)
adudinsk
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Re: Carb rebuild/cleaning

Post by adudinsk »

To Winterize this is what I do.
1) put marine stabilizer in the fuel.
2) Run OB for 10 min to ensure fuel is in carb bowl
*you could disconnect the fuel hose.. and run the carbs dry.. but that can lead to other issues with the gaskets/humidity/etc
(some ppl do it this way.. some do not.. 50/50 )
3) Change oil/filter in case there is any water in the oil (often from condensation) You dont want it to freeze
4) Drain and change the lower end oil (check for water it will be milky white.. maybe you need to do your seals..)
So all fluids are changes.. so no water is in them.. and you are GOOD TO GO next season.
5) Store OB upright, and centred so any water will drain
6) There is a tube that water is in .. that makes the stream out the back. Disconnect. Blow it out to get all water out of that.
7) Optimally, remove each spark plugs.. put a tiny bit of engine oil in the cylinder (or fogging fluid) and HAND rotate the flywheel a few rotations to coat insides well... Not needed with a QUICK spray of fogging oil/fluid
8) Reinstall plugs.. finger tight.. then 1/4 turn more.. or better yet.. torque wrench it to speck
9) Next season/spring replace fuel filter

Now is a good time to touch up paint the OB if needed..
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opie
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Re: Carb rebuild/cleaning

Post by opie »

For the sync question above:
I have taken off the carb manifold and cleaned the carbs and bowls 5 times over 10 years. I never touched the sync. The 1999 BF50A hums along just fine. I adjust the idle screw occasionally.
I don't know why your sync was disturbed.
adudinsk
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Re: Carb rebuild/cleaning

Post by adudinsk »

No idea.. they were all off.
When I bought it it would stall at low idle.
Adjusted the master idle.. (It for sure was too low) that helped.. but it had a cough.

The individual idle controls were still painted.. never touched..
But all carbs were out of spec.

I did change all the gaskets, all float valves, and jets. Everything that could be changed was.

That helped. But it still coughed a bit..

Syncing fixed that 100%. Checked at a variety of RPMs.. all out.. (was hoping that it was synced at ONE RPM setting.. not)
Synced at 3000 RPM
Idles fine.. but purrrrrs at 3000.. much better fuel burn

My other post showed what the carbs looked like inside (filthy! full of residue from long term use of alcohol in the gas!)
I have been told by DynoLab, (worked for years at one of the big 3) that use of alcohol in your gas (seafoam/low test gas/etc) will cause acid if left in the bowls over the winter. They looked at the photo of the carbs.. all the old timers laughed.. said long term use of low grade gas/alcohol/etc/
(Note: Around here several places were fined for selling REGULAR gas as SUPER..)

(never checked PH.. nor alcohol content in my local gas...note to self.. time to experiment .. I have a lab grade ph meter!)

This alcohol does supposedly affect the carbs over time.. who knows.

If you own a carb'ed motorbike, its pretty standard to sync every season. So I took a gamble, bought the gauges.. and presto got lucky.. that fixed it up. They just go out.. wear/ vibration.. even if adjustments are not touched. If its in spec you will just not need to adjust.. piece of mind.

So pretty much now.. all I have to do is check valve lash.. (pain in the backside to correct with my style of motor.. hope its in spec..)...

I rebuilt the lower end. All seals/anything rubber/impeller/all moving parts other than some of the large bearings/gears were replaced. (but all were checked) (Lower end Oil was FULL of water.. ONLY the outer seals were ever changed inner was rusted to death.. looked original, could not tell.. totally rusted. Don't trust a mechanic / repair shop)

Rebuilt all carbs.
New Plugs/Wires on the way
New Voltage Regulator (mine was blown to bits.. had a HOLE in it .. in another post)
New internal engine anodes. (3)
Went through all ignition components and check to ensure all were in spec. (they were)
Checked charging.. working now that Voltage Regulator was replaced
Check Fuel Pump output.. looks good.. (will buy and ORIGINAL (not import) replacement to have on hand.. no rebuild kits available)

Bought many spare parts as they are hard to find for my 2005 OB.. VERY hard to find ignition parts..they are simply not made.
So I am pretty good to go, and feel very confident in the OB.
And did learn a lot about my OB. Enjoy working on stuff like that.

AD
macowneril2015
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Re: Carb rebuild/cleaning

Post by macowneril2015 »

adudinsk wrote: Wed Oct 14, 2020 4:16 am No idea.. they were all off.
When I bought it it would stall at low idle.
Adjusted the master idle.. (It for sure was too low) that helped.. but it had a cough.

The individual idle controls were still painted.. never touched..
But all carbs were out of spec.

I did change all the gaskets, all float valves, and jets. Everything that could be changed was.

That helped. But it still coughed a bit..

Syncing fixed that 100%. Checked at a variety of RPMs.. all out.. (was hoping that it was synced at ONE RPM setting.. not)
Synced at 3000 RPM
Idles fine.. but purrrrrs at 3000.. much better fuel burn

My other post showed what the carbs looked like inside (filthy! full of residue from long term use of alcohol in the gas!)
I have been told by DynoLab, (worked for years at one of the big 3) that use of alcohol in your gas (seafoam/low test gas/etc) will cause acid if left in the bowls over the winter. They looked at the photo of the carbs.. all the old timers laughed.. said long term use of low grade gas/alcohol/etc/
(Note: Around here several places were fined for selling REGULAR gas as SUPER..)

(never checked PH.. nor alcohol content in my local gas...note to self.. time to experiment .. I have a lab grade ph meter!)

This alcohol does supposedly affect the carbs over time.. who knows.

If you own a carb'ed motorbike, its pretty standard to sync every season. So I took a gamble, bought the gauges.. and presto got lucky.. that fixed it up. They just go out.. wear/ vibration.. even if adjustments are not touched. If its in spec you will just not need to adjust.. piece of mind.

So pretty much now.. all I have to do is check valve lash.. (pain in the backside to correct with my style of motor.. hope its in spec..)...

I rebuilt the lower end. All seals/anything rubber/impeller/all moving parts other than some of the large bearings/gears were replaced. (but all were checked) (Lower end Oil was FULL of water.. ONLY the outer seals were ever changed inner was rusted to death.. looked original, could not tell.. totally rusted. Don't trust a mechanic / repair shop)

Rebuilt all carbs.
New Plugs/Wires on the way
New Voltage Regulator (mine was blown to bits.. had a HOLE in it .. in another post)
New internal engine anodes. (3)
Went through all ignition components and check to ensure all were in spec. (they were)
Checked charging.. working now that Voltage Regulator was replaced
Check Fuel Pump output.. looks good.. (will buy and ORIGINAL (not import) replacement to have on hand.. no rebuild kits available)

Bought many spare parts as they are hard to find for my 2005 OB.. VERY hard to find ignition parts..they are simply not made.
So I am pretty good to go, and feel very confident in the OB.
And did learn a lot about my OB. Enjoy working on stuff like that.

AD
So I am finally going to do it myself, the mechanic has had boat for over 6 weeks and has no idea when they will get to it. My instructions just have measurements for ignition and carb syncing no vacuum pressures or suggestions so do I still need the tool? Sorry just a little nervous attacking this for the first time.
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