Need some help/rough idle

[Newbie@boats]

Update: Got the part in for my carb and its all back together and running......

Took a few minutes at home to sync the carbs then headed straight to the lake....

Boat ran great idled no problem at the dock for 15 minutes took it out for about 25 minutes brought it back to an idle no problem.....

Now heres what I have done so far.....

Cleaned and went thru the carbs for the second time, replaced the fuel tank, fuel filter, and spark plugs.....

The only thing I am worried about I was checking the sync out on the water because I know that can change the way the boat runs....Sync definitely seemed in spec but when I "blipped" the trottle it would idle real low and catch itself not sure if this is normal or not, and second is around 2200-2700RPM it kinda misses and bucks but lower RPM or HIGHER boat runs perfect.....Now I tried to make that happen at the dock and it would hardly do it so while it was doing it I tried to adjust the air/fuel screws and it seemed to smooth itself out.....not to sure if I should try the sea foam fuel additive or yamaha ring free.....I just want this problem solved so I can enjoy the summer fishing

I am uploading a video to see what you guys think


https://vimeo.com/217935236

[panasonic]

Did you replace the fuel pump diaphragm and gaskets.? I think you said you had it apart and found rust in there, not sure if that is correct.

A weak fuel pump maybe the last piece of this puzzle. The diaphragm and gaskets are pretty cheap to replace.

Another option is teeing in a pressure gage to the fuel line on the engine after the pump and watching it closely, see if the pressure drops or fluctuates when the stumbling occurs.

One more thing. Crack the cap on the new tank to make sure it is venting.

[Newbie@boats]

Did you replace the fuel pump diaphragm and gaskets.? I think you said you had it apart and found rust in there, not sure if that is correct.

A weak fuel pump maybe the last piece of this puzzle. The diaphragm and gaskets are pretty cheap to replace.

Another option is teeing in a pressure gage to the fuel line on the engine after the pump and watching it closely, see if the pressure drops or fluctuates when the stumbling occurs.

One more thing. Crack the cap on the new tank to make sure it is venting.

I actually replaced that fuel pump as well. I assume you're talking about the one on the engine? When I went to remove the fuel line I broke one of the nipples off so that's new.

I didn't check the venting

[TownsendsFJR1300]

Sounds really good in that video!!

And no, the idle should not drop below(when slowing down quickly) and then rise back up.

IME, Seafoam works ok. RF, MUCH stronger, especially when used at a shock mixture. I would do that next myself.. Can't hurt anything and can only help clean out any remaining varnish, etc PLUS, help clean the top end of the engine..

[Newbie@boats]

Sounds really good in that video!!

And no, the idle should not drop below(when slowing down quickly) and then rise back up.

IME, Seafoam works ok. RF, MUCH stronger, especially when used at a shock mixture. I would do that next myself.. Can't hurt anything and can only help clean out any remaining varnish, etc PLUS, help clean the top end of the engine..

When I am in gear and doing 3/4 throttle and i pull it instantly back into N and the RPMS stay cosistent they don't drop out like they did in that video.....

So my next steps should be to put some Yamaha Ring Free in the fuel system and see what happens?

Im fairly confident the carbs should be an issue at this point-maybe some fine tuning but should have to remove them and tear them apart again.....

Now when I push the key in for the "choke" to be applied it doesn't click or do anything, but being 90* out I wouldn't imagine the choke would be an issue at all as long as its in the "off" position

And from what I see 1oz of the RF covers 10 GAL on fuel....I only have a 6 gallon tank LOL......

[FabricGATOR]

Fod

In aviation we use the term FOD (foreign object damage)

In the very first few posts four pages ago, I said to myself that it sounds like something is clogging passage.

Now, I understand that a few disassembles and a fuel pump later it runs great and then, suddenly, it does not.

Ensure that every section of the fuel path is debris free. There are multiple places designed into the system to catch debris (filters, bowls, etc) because just a little piece speck of junk FOD will change how the system works in harmony with one another.

I apologize, I know this is standard procedure and I am not implying that this obvious step was not performed... but, even when you are meticulous and clean, clear everything, occasionally yet just another piece of FOD will ruin your fishing day.

And any combination of SeaFoam, RingFree, StarTron, or that new aerosol rebuild kit in a can is not going to fix it.

[Newbie@boats]

In aviation we use the term FOD (foreign object damage)

In the very first few posts four pages ago, I said to myself that it sounds like something is clogging passage.

Now, I understand that a few disassembles and a fuel pump later it runs great and then, suddenly, it does not.

Ensure that every section of the fuel path is debris free. There are multiple places designed into the system to catch debris (filters, bowls, etc) because just a little piece speck of junk FOD will change how the system works in harmony with one another.

I apologize, I know this is standard procedure and I am not implying that this obvious step was not performed... but, even when you are meticulous and clean, clear everything, occasionally yet just another piece of FOD will ruin your fishing day.

And any combination of SeaFoam, RingFree, StarTron, or that new aerosol rebuild kit in a can is not going to fix it.

I blew out every fuel line, replace the fuel line/primer ball hose, new gas tank, literally everything is new besides the fuel line on the back of the carbs.....I will probably play with the air/fuel screws some more. If the problem still happens I don't know where to go from there...short of dropping it off at the dealer-or buying brand new carbs.....ill be stumped....I doubt it would be an electrical issue.....

[Newbie@boats]

The thing I circled in red is the choke actuator I assume? Because I cannot get that to do anything no matter which position i turn the key or it being pushed in, but when I unplug it and apply 12V to it I can get to to activate either pulling the plunger in or pushing it out which I assume operates the choke? Also, I am trying to figure out if I should look into this issue for my situation or leave it alone until I have the motor running 100% thru all RPM ranges...

Also, whats the one circled in blue do? Again, I never hear that one click or do anything as well.

[TownsendsFJR1300]

When I am in gear and doing 3/4 throttle and i pull it instantly back into N and the RPMS stay cosistent they don't drop out like they did in that video.....GOOD

So my next steps should be to put some Yamaha Ring Free in the fuel system and see what happens? I WOULD..

Im fairly confident the carbs should be an issue at this point-maybe some fine tuning but should have to remove them and tear them apart again.....
YOU CAN SIMPLY REMOVE THE DRAIN PLUGS AND CATCH WHAT COMES OUT IN A CLEAN CONTAINER. PRIMING THE PRIMER BULB WILL HELP FLUSH ANY LOOSE PARTICLES OUT.

Now when I push the key in for the "choke" to be applied it doesn't click or do anything, but being 90* out I wouldn't imagine the choke would be an issue at all as long as its in the "off" position AS LONG AS THE CHOKE BUTTERFLYS ARE OPEN ONCE STARTED, IT WON'T MAKE A DIFFERENCE IN THE HIGHER RPMs. YOU CAN TEST THAT CHOKE SOLENOID (CIRCLED IN RED).

And from what I see 1oz of the RF covers 10 GAL on fuel....I only have a 6 gallon tank LOL......

That mix is for regular usage. Shock treatment is 2 OZ / ONE GALLON. One tank full of shock is plenty..

[Newbie@boats]

That mix is for regular usage. Shock treatment is 2 OZ / ONE GALLON. One tank full of shock is plenty..

Ok, the local dealer is closed today I will get some tomorrow and give it a shot and see what happens!

[Newbie@boats]

Quick question, would it make sense to use sea foam to clean out the carbon in the cylinders? I figure If I remove the plug on the intake manifold I can stick a hose into the seafoam can and that will suck it right into the cylinders and I can let it sit for a little while then start it back up and let it clear everything out.....make any sense or not worth the time and effort?

[TownsendsFJR1300]

Quick question, would it make sense to use sea foam to clean out the carbon in the cylinders? I figure If I remove the plug on the intake manifold I can stick a hose into the seafoam can and that will suck it right into the cylinders and I can let it sit for a little while then start it back up and let it clear everything out.....make any sense or not worth the time and effort?

I do something similar with my small engines (never did the Yamaha OB-never needed too).
I do it both for internal cleaning and storage.

I put a teaspoon or two with a syringe into the spark plug hole, rotate the engine over slowly to distribute it (spark plug out). You obviously don't want a hydraulic lock.

(I store the engine at TDC so no air access's the combustion chamber.)

For your multi cylinder engine, you'll be able to get SF soaked around the rings (as the pistons are at different area's of their stroke). I'd squirt some in all the cylinders and let sit over night.

So, the "soak" won't hurt anything, just crank over with the spark plugs OUT before starting- again so there's NO hydraulic lock..

**Yamaha actually makes a product EXACTLY FOR THIS, DEALER PURCHASE/USE ONLY. Rodbolt has posted, this product has a VERY high success rate.

I'm not sure if this (probably not), is the same product:
http://www.boats.net/parts/detail/ya...EAN-D1-00.html




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[Newbie@boats]

I really don't want to give an update and curse my luck but I definitely want to keep you guys posted.

Took the boat out again tonight for a few hours of fishing....

Ran absolutely perfect. No misses, no bucking, smooth as silk!

Only thing I did before I went out was dumped a bottle of sea foam into the tank so either that fixed/covered up the issue or the issue is actually gone now.

Even after tilting the motor up which I was very worried about because last time I did that it's when the issue showed up but it was great.

Going back out in the morning. If you don't hear from me then everything is well. If you do then things aren't so great

Thanks again for everyone's help truly appreciated.

[99yam40]

I really don't want to give an update and curse my luck but I definitely want to keep you guys posted.

Took the boat out again tonight for a few hours of fishing....

Ran absolutely perfect. No misses, no bucking, smooth as silk!

Only thing I did before I went out was dumped a bottle of sea foam into the tank so either that fixed/covered up the issue or the issue is actually gone now.

Even after tilting the motor up which I was very worried about because last time I did that it's when the issue showed up but it was great.

Going back out in the morning. If you don't hear from me then everything is well. If you do then things aren't so great

Thanks again for everyone's help truly appreciated.

or if you do not post back it could mean you could not get back to port

[Newbie@boats]

or if you do not post back it could mean you could not get back to port

Oh I'm always making it back to port! Got my *****ing motor as a back up!

Unless they both act up then I'm screwed!