OX66 LP Fuel Pumps

[fishinAK1]

Thank you! Dennis
The portable tank I was using has one of this new caps w the vent integrated into it. So ya it was “open”.
I just had the injectors clean last month, as I thought they were causing this issue. Brucato FIS cleaned them. He said the filter baskets were spotless. However they were all 6 running “rich”. Between 2-6%. After cleaning he adjusted them and retested. He was able to get them all back to spec.
He did mention that it was very uncommon to have all 6 be running rich though... Thought maybe it was just because they had never been done...
Is it possible that one of the injectors (probably the one the was 6% outta spec) failed?

 

[DennisG01]

Is it possible that one of the injectors (probably the one the was 6% outta spec) failed?

From my experience, I would say that that is WAY down on the possibility list. As in so far down the list, I wouldn't be worried about it. I don't know that shop, but if they're reputable, then those injectors come back basically like new. But because it's free and easy... pull the spark plugs and compare them - they should all look relatively the same (be sure to label them). If I remember correctly, the stbd bank is slightly higher than the port - so the stbd side is 1-3-5.

 

[fishinAK1]

Good to know!
I will pull all the plugs and take a pic today. I did pull #1 after yesterday evening test. It was pretty damn black and wet.

As PM anyway I was going to replace the Racor (usually do this every spring anyway). To minimize trips to the hardware store, I was gonna pickup a length of fuel line to replace between the Racor and outboard. What size is stock? What do you recommend? Seems to be no concencus on the interweb. 3/8 vs 5/16.

 

[fishinAK1]

Interesting!

So here are the plug pics. Numbered as starboard 1,3,5 and port 2,4,6 top to bottom.
All look very similar, EXCEPT #6.

first 5 appear most dry with electrode ceramic white and black around first 2 threads. #6 is wet with black electrode and ceramic and no black build up around threads.

These are brand new plugs 3 weeks ago just after cleaned injectors were reinstalled. Only about 2 hours runtime.

NGK BR8HS, per manual.

I did notice a couple of the tips not screwed down tight. Does that matter?

Whatcha think?

 

[family affair]

I've never studied the induction system on an ox66, but if each injector feeds a cylinder, #6 appears to be running really rich.
What are the symptoms of a broken reed?
Also, what fuel additives do you run?

 

[fishinAK1]

I keep reading that some OX66 drop a cylinder or 2 at low rpms. Does anyone know if this 2005 200 hp saltwater series 2 does that? Would that explain 1 plug looking so different?
Could be rich but since injectors were just recalibrated to spec...could it be that it’s not getting good hot spark? Bad coil pack?

As far as additives I usually dump a can of seafoam into every 80 gal fill up. And usually stabil in the fall.
I’ve been running Yamalube oil for 10 yrs.

 

[DennisG01]

I would assume your 200HP is the same as my 250HP... in the end, this doesn't affect what you have going on, though, but... around idle, spark is dropped on #5 and then somewhere in the low to high 1,000 range, #2 and #5 are both dropped. #6 is never affected.

Did you gap the plugs before putting them in? Do you have, or can you borrow, a compression tester?

Tips... maybe - not sure - guess it all depends on how well it's still transferring juice. Clean the plugs up real well, tighten the tips, maybe even swap that plug to a different hole. Run it for another 30 minutes - run it hard - and then check them again.

Also, try this - as the engine is idling, remove the boot from #6... any difference in idle? Don't give yourself a jolt! Use insulated pliers.

 

[seasick]

Although I have removed the plug wires to check if the revs drop, it is not recommended by Yamaha. They recommend a spark tester ( a tool with it's own gap that will also have a spark jump the gap if the juice is good.
You can buy cheap spark testers at HF. Not the best but better than nothing.
Plug 6 looks terrible. Did you smell it or feel the goop on the tip?? ( I think I have asked that before). Before you do any testing run compression tests with all plugs out ( and in theory withe the ignition disabled). Cyls 3 and 6 should read a bit lower compression than the other 4.
After that you need to clean the plugs with something like carb cleaner or maybe even WD40 depending on what the buildup is. Then do the spark test. You can do the test at higher revs also to insure that the ECU is firing all cylinders.

How big is your gas tank? (I am curious)

Confirm that plugs are BRHS8-10

 

[Sparkdog118]

The plastic plier test (pulling the plug wires off one by one) works best when you idle up the motor while under a load in gear. The higher the rpm, the more evident the problem is. If you clean the plugs, switch 4 and 6 injector, see if the problem moves. If 4 plug is still burning good, then the injectors are good. I would then suspect the intake and reed gaskets. I posted a pic last week of the gasket layout when you were talking about the injectors running rich. They get old and leak. That was my first impression of the problem. They blow out sometimes when the injectors run rich and backfire thru the intake. They are easy to change and not expensive.

 

[fishinAK1]

Ok great ideas, Thank you team!

I DID smell the plugs. No strong gasoline smell. But the wetness was thin like gas. Plugs are BR8HS-10.

So I SHOULD NOT pull the boot while engine is running? Any way to check without a

I will clean the plugs and try the injectors switch.

But can I ask again, could it be the coil pack? I was just thinking this may be easier to switch and check than pull off the intake. Although the intake and reed gaskets cause does certain make sense.

Thank you again I’ll report back.

btw how aggressive can I get with the cleaning the plug electrodes?

also I did check compression before pulling injectors. Cold, all 6 cylinders within 10% of 120.

 

[seasick]

I have pulled plug wires and didn't kill coils. I have also run a SX on the flush port only

Don't add more variables. Clean the plugs and put back in same cyls for now. You can use a thin file or emery paper to clean the electrode but you wan't to make sure that you get every bit of grit cleaned out before reusing.
When yo do the test, start at idle and pull the plug wire one at a time. Nate what happens. Now raise the revs to about 1200 or so and redo the test.

 

[DennisG01]

Nah, go ahead and unplug it. There's what "Mother" Yamaha says, and then there's what we know works just fine. I'm only guessing, but the Yamaha recommendation could simply be due to a CYA thing.

If you have a brass or SS detail cleaning brush (they're cheap at Harbor Freight), those work well, too.

 

[seasick]

Dennis, I was wondering where you were today.

 

[Sparkdog118]

I usually pull the plug wires off between 1200-1800 rpms in gear to diagnose which cylinder is not at full power on all models. Easy to compare each cylinder ‘s performance. Plastic ignition pliers work the best.

 

[fishinAK1]

So quickly b4 I pulled plugs to clean I ran in bucket for a couple minutes. Pulled #6 wire off plug. No change! At 1000 rpms, 1600, or 2700 rpms.

But then I pulled the wire off #5 (at idle) didn’t notice much, if any, change there either. But I did on #4....

i got curious and pulled off the #6 coil pack. Pretty corroded connections.,,

testing coil pack resistance now. Anyone know what the resistance should be?

 

[DennisG01]

Dennis, I was wondering where you were today.

I'm here - I just wasn't there.

 

[Sparkdog118]

If you switch 6 coil with 4 and then pull the wires while running. See if 4 is dead or is thill firing.also, if it is not firing, a timing light will not light.

 

[DennisG01]

So quickly b4 I pulled plugs to clean I ran in bucket for a couple minutes. Pulled #6 wire off plug. No change! At 1000 rpms, 1600, or 2700 rpms.

But then I pulled the wire off #5 (at idle) didn’t notice much, if any, change there either. But I did on #4....

i got curious and pulled off the #6 coil pack. Pretty corroded connections.,,

testing coil pack resistance now. Anyone know what the resistance should be?

Since the #5 doesn't fire at all at idle, that part makes sense. But pulling the #6 should have caused the same results as #4. THAT is sounding like good news!

I'm not sure on coil pack specs offhand - I'll check the SM later. But, clean it up real good and see what happens!

 

[fishinAK1]

Eureka!
Swapped coils 4 & 6. Then pulled wires on each. Pulling 6 resulted in very noticeable change. Pulling 4 resulted in little to no change.

Then switched coils back to original, and noticeable engine change back to 4 not 6.

Please correct me if I’m wrong, but this MUST mean bad #6 coil (or wire).

 

[DennisG01]

Eureka!
Swapped coils 4 & 6. Then pulled wires on each. Pulling 6 resulted in very noticeable change. Pulling 4 resulted in little to no change.

Then switched coils back to original, and noticeable engine change back to 4 not 6.

Please correct me if I’m wrong, but this MUST mean bad #6 coil (or wire).

Yup. That means everything upstream of the coil is working properly and the issue MUST be the coil or plug wire. Now, what I honestly can't recall is if the wire is a separate entity from the coil - if it is, try swapping wires. If it turns out to be the wire, I would probably replace all 6. If it turns out to be the coil (or the coil/wire are separatable), I would only replace the defective one as these tend to be pretty robust and failure is not common.