Shock Treatment F150

[northern fisher]

6oo hours on this F150 motor ... fouled out 3 spark plugs. Would a 'shock treatment' be the first thing to do before one pulls the head off???
Need some advice please ~

[rodbolt17]

a leak down test would be the first thing I would do.

[TownsendsFJR1300]

Besides the above, have you noticed ANY OIL BURNING??

[northern fisher]

Leak down was done, now they want to polish & port the head for the cost ($1700) of a new head assembly ($2159). The shop doing the work is not Yamaha certified .. my guess now is to find another shop that is certified.

[TownsendsFJR1300]

Valve guides wear, valve seals wear, port and polish the head???

Agreed, I'd be looking for another certified shop as from what you say, you simply need a valve job...

[boscoe99]

What were the results of the leak down test?

Where was the leakage noted from?

Did they also do a compression test? If so, what were the results?

Are you mechanically inclined at all? To remove an F150 cylinder head would not take much time. Take it to a machine shop and let them resurface the valves and seats if that is wear the problem lies.

I would install a brand new head (all new valves/springs/camshafts/everything at $1900 before I would drop $1700 into repairing a defective head.

2006 and Later F150TLR Yamaha Outboard CYLINDER CRANKCASE 2 Diagram and Parts

[99yam40]

yep, need to know what the leak down test said.
If rings were stuck I can see low compression and leaking into crankcase.
valve guides would leak into the valve covers.
not seating valves would leak into the intake o=r exhaust
I see no reason to port and polish a head . That is what they did to get race motors to let more air and fuel from carbs into the cylinders to create more power

[robert graham]

Are 3 plugs fouled with fuel(over-rich mixture) or oil-fouled?...maybe your fuel enrichening system is stuck in the on/cold start position?... Just a thought...before you spend a lot of money on cylinder head....

[TownsendsFJR1300]

Something sounds very funky about the whole answer he got from the shop.

Port and polish?? C'mon....

Someone's ****ing him around.. I wouldn't be going back to that shop..

[bajakeith]

Omg lol !!

Ya got to be kidding..find a good boat tech/mech..and having a certified shop/mech dosnt mean anything about anything except taking a stupid test..what your looking for is a guy that's has a good rep.,,looks you in the eye,, and has a clue about a outboard..Its Damn had to get me FLABBERGASTED,,but this one has done it.....LOL Port and polish..thats after the muffler bearing right...just before the turn signal oil

[rodbolt17]

hay, ya gotta change the turn signal oil sometimes.
or simply replace the altenator.
look on the shop wall.
if no training certs are there , go someplace else.

[northern fisher]

Something sounds very funky about the whole answer he got from the shop.

Port and polish?? C'mon....

Someone's ****ing him around.. I wouldn't be going back to that shop..

Yup, I took it to a non-certified Yamaha marine "RIP-OFF" ... I mean "Repair Shop". Checked the online Yamaha repair shops ... and these folks had me at ... "Sure, bring it IN"
Hooking up with the only cerified JEDI Shop and I won't be fishing till next season. Thanks for the input and making me realize ... a Yamaha LOGO on the building, don't mean squat.

[greasyshaft]

I have a Yamaha sticker on my tool box ;D

[TownsendsFJR1300]

If YOU can get that leak down tester (some auto parts stores rents tools, IDK if they would carry this tool) and a small air compressor (and follow the directions-its not hard), You can get an idea what's going on.

A little knowledge on your end doesn't hurt walking into the shop.

Major air loss, (as noted above from different areas) will give you a very good idea of the issue.

**At this point, I don't think a shock treatment would hurt anything. IMO, I would tilt the engine up fully, pull the plugs and put a couple of teaspoons of Seafoam in each cylinder, (LEAVE THE PLUGS OUT). Crank over just a little to distribute the SF. Let sit at least over night. Before starting, crank over to blow out any left over fluid (so there's NO hydraulic lock). Then, run a heavy dose 2-3xs the recommended amount of Yamaha's Ring Free(maybe with a 6 gallon portable tank). You might luck out.


I posted in another thread the tool should you buy one, not terribly expensive and easy to operate(you do need an air compressor-just a small is fine, capable of about 100PSI);


https://www.otctools.com/products/cy...age-tester-kit

[rodbolt17]

have a leakdown test done. if the rings or a valve are not sealing this will tell you.

just did a service on a pair of F150's with 2700 hours.

oh, leaking valves rarely cause fouling without excessive oil consumption.

flagship marine can typically do that head for about 350 dollars and it only takes a few hours to remove/install.