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Discussion Starter #1
Hello,

Have been dancing with my R6 over this seemingly fuel related issue. It didn't happen for the first few months I owned the bike, but started up as I began to put more miles on it. The engine will just start idling like lopey crap (lope a bit, single high rev, lope some more...). Then the bike sputters and sounds like a crappy V-twin until I hit 4k RPM, where it then takes off like a rocket ship and I don't have issues until I have to take off from a stop again.

The first time I stopped this issue, I did so by opening my fuel tank. I've had a similar issue in my 4Runner. Thought I was out of gas, opened the cap and it started running perfect again. This doesn't work every time. What does seem to work is fuel system cleaner. I dumped a whole ass 21 gallon treatment bottle in my tank and the bike started running fine. Just recently, I started having the issue on an evening ride. Next morning, I took the bike for gas and it had the issue all the way to the gas station. Fresh gas, still running like crap. Put another bottle of cleaner in, didn't get out of the parking lot before it cleared up and started running tits.

I really hope I'm not going to have to keep dumping a 10 dollar bottle of cleaner every couple tanks of gas. It happened to me again tonight so I'm going to test my "fix" tomorrow. I plan on recording it, as I've purchased a few bottles of fuel system cleaner in my day and never noticed any improvement. It will be interesting to document a case of "gas station magic juice" actually working :LOL:
 

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YZFR6... ooodles of HP
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Plugs or coil (s) are the culprit.
 

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Discussion Starter #3
Plugs or coil (s) are the culprit.
Interesting take. The coils are all Mitsubishi, and I just did the plugs a few thousand miles ago. The plugs I pulled out were 11 or 12s or something, so maybe he had those hot plugs in there to stop the fouling?? I put in 9s I believe. I have a hard time believing that the fuel system cleaner is capable of cleaning a fouled plug almost instantly. The bike runs quite rich, and I've never tuned the power commander (no laptop), so I'll put tuning next on my to-do list.
 

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YZFR6... ooodles of HP
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10 should be stock plug. PC? yes that definitely can be the issue.
 

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Discussion Starter #5
10 should be stock plug. PC? yes that definitely can be the issue.
OK I double checked the plug situation. Pulled the old ones out of the garbage, CR8EK. Looked at my receipt for the ones I put in, CR10EK. I thought the plugs went up as they got hotter, other way around.

I know people like to dog the PC for wiring problems, but I know it isn't that. I'll tune it and see what's what. Can you just use any old phone charger for tuning the power commander?
 

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Discussion Starter #6
Started the bike and it didn't have the issue. Added the treatment anyways. I was using some old Gumout crap I had leftover from a few years ago. I also bought an emergency !!!10 dollar!!! bottle of STP treatment from a gas station (that's a 20 dollar tank of gas, same as my car!). I just bought two cans of Sea Foam.

I'll try to update (not that anyone cares :D) when I have the issue again.
 

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Manual calls for CR9EK or CR10EK.
Make sure you gap them per specification.
Side note, I'm currently running 8s, probably only because they're iridium and not copper. It has a microscopic head compared to the stock copper, which means they're a hellova lot easier to fowl. NGK manufacturer actually designates their other large surface area plugs like our stock ones as "anti-fowling". Even with the hotter plug, still need a hotter engine to keep from fowling them. At first I though it was running rich but now think it has been leaning-out. (less power with hot engine in cold air, as opposed to hot engine in warm air) For second gen at least, there's a way to tune fueling without an add-on.
 

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Discussion Starter #8
Manual calls for CR9EK or CR10EK.
Make sure you gap them per specification.
Side note, I'm currently running 8s, probably only because they're iridium and not copper. It has a microscopic head compared to the stock copper, which means they're a hellova lot easier to fowl. NGK manufacturer actually designates their other large surface area plugs like our stock ones as "anti-fowling". Even with the hotter plug, still need a hotter engine to keep from fowling them. At first I though it was running rich but now think it has been leaning-out. (less power with hot engine in cold air, as opposed to hot engine in warm air) For second gen at least, there's a way to tune fueling without an add-on.
I pretty much run standard OEM stuff for service items. It is the only way to go with old Toyotas, I figure it can't hurt with these bikes either. People thought they were gonna gain 20 freakin HP from their MSD cap and wires...ends up running like junk.

I chose the 10s because the 9s are for California bikes, and we all know how the California emission bureaucrats operate :)

There's definitely something up with my gas tank venting though.
 

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YZFR6... ooodles of HP
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CA and 10s here rin nice.
 

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Discussion Starter #10
I haven't even ridden the bike today. I wanted to refresh my shifting, so I bought a new shift lever toe thing (the lil rubber thing your foot hits), two shift springs, and a gasket for the cover. I was able to replace the little spring that returns the lever to center, but it appears the big spring (90508-295B2) is secured by a welded plate and cannot be replaced. That was a bummer because I spent 20 bucks and didn't make a difference besides I know that spring won't break.

I'm currently stripping the paint off my rear sets, someone painted them with something a long time ago and now it's peeling and looks like garbage. I have the left side stripped so far, looks 10x better.
 

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Discussion Starter #11
Got one side of my rear sets done, looks tits. They have a brushed finish because I used a metal prep pad to scrub the remaining spots of paint off. I am debating mirror polishing them but that might look a little ricey.

Took the bike out for a ride and now I'm stumped. I poured a bit of Sea Foam in earlier today while the bike was parked, and poured quite a bit in right before I left. I probably got 10 miles down the road before it started running like fawkin crap again. I bought a 5 dollar bottle of fuel system cleaner (all they had was STP High Mileage Fuel Injector & Carburetor Treatment) and I feel like it may have helped at first, but then it ran like crap for the rest of the night (3 hour ride).

Here's what I'm thinking. I have probably 30 gallons worth of fuel treatment in my tank right now. I don't want to dilute my fuel anymore, so I'm going to ride through this tank and try a different cleaner. The two cleaners I used before with results were "Gumout Regane" and "STP High Mileage Complete Fuel System Cleaner". The cleaners I used tonight were Sea Foam and "STP High Mileage Fuel Injector & Carburetor Treatment".

In my research, I found that the only cleaners that are honestly worth a sweet fawk are ones with polyetheramine. The two cleaners that worked contain pretty hefty doses of polyetheramine, the ones that didn't work don't have any polyetheramine.

On a side note, I did get to cruise stop light to stop light with a shoal of gixxers... lol those guys. Cheap ass helmets, no gear, shorts, t shirt and sneakers, and popping wheelies all down the street.
 

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YZFR6... ooodles of HP
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Intermittent can only be caused by

Plugs
Coils
Fuel volume (tune)
 

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Discussion Starter #13
I'm pretty sure it's tune related, but I want to know why it fixes when I add certain fuel system cleaners.

Bike started up fine again this morning, so I'm going to keep a bottle of Gumout on me and dump it in when the bike acts up.
 

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YZFR6... ooodles of HP
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The octane rating of the fuel is changing adding sea foam or other products. Ie. 91 octane is becoming say 87 octane. Could be lower. I'm not a lab. I just know it is less then the fuel started. Also, my 2017 doesn't have a fuel return line. You may not be adequately mixing in the tank and sucking up mostly the product additive in the gas at that time. Then lower octane initiates a pre ignition and or more complete burn even with the extra volume if your tune is off.
 

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Discussion Starter #15
I don't use any sort of fuel additives unless I'm having an issue. I typically fill my bike when I have about 20 miles on my F trip (closer to 15 actual miles with my 15/50 sprockets), so I would have very little additives left in the tank. Sometimes I worry about stale gas, as hardly anyone pumps 91. It normally smells pretty fresh, so I don't worry. I do find myself questioning the half gallon of 87 left in the hose from the last guy. I think these are unrelated though, and have a minor impact on the overall octane.

Right now, I have up 30oz of fuel system cleaner per full tank and it is doing the same as when I have a fresh tank of 91 with no additives.
 

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Discussion Starter #16
Dumped a bottle of Regane in there for the hell of it, no change. Guess it's time for more plugs and a tune. While I'm in there, I think I will replace the valve cover gasket as it is leaking the tiniest ring of oil on all 4 coils.
 

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I pretty much run standard OEM stuff for service items. It is the only way to go with old Toyotas, I figure it can't hurt with these bikes either. People thought they were gonna gain 20 freakin HP from their MSD cap and wires...ends up running like junk.

I chose the 10s because the 9s are for California bikes, and we all know how the California emission bureaucrats operate :)

There's definitely something up with my gas tank venting though.
You'll get nothing but thumbs up from me on that sentiment. Unfortunately, couldn't find OEM spec ignition coils anymore. Those that claimed they were OEM, revealed otherwise when testing primary/secondary coil resistances. The higher resistances of non-OEM, while producing a hotter spark, also meant much less gap tolerance. That's what made me test out the possibility of going FURTHER off-spec with NGK's Iridium plugs. This was before I knew of a way to tweak fueling without add-on. Stock plugs as you know are copper and copper while the best performing, requires frequent re-gaps. 2nd-Gen manual recommends just 8k for maintaining peak performance. As long as I can keep'em clean, the iridium should be several times that.
 

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YZFR6... ooodles of HP
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Did you ever check the coils with an ohm meter?
 

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Discussion Starter #19
Did you ever check the coils with an ohm meter?
No, I had no reason to when I was in there. When I did the plugs I had only ridden the bike for a few hours. The first night of owning the bike, I dropped it while going down my driveway and a rock punched through the stator cover. My driveway is a steep chipseal hill with decorative 1/4" pea gravel over the chipseal. It is like marbles on concrete lol. I would have welded it up right there, but I needed a new stator anyways so I waited for everything to ship in before fixing the bike. Ended up being down for a month.

The bike ran perfectly fine for multiple 500 mile trips. 7 weeks after the new plugs, I first had this sputtering issue. I'm starting to wonder if it's some kind of Power Commander fault at this point.

I can't think of why plugs or coils would cause sputtering below 4k RPM with no consistency for when/why it happens. It's only at low revs too, and it's totally different every time. The first time, it was so bad my bike would shut off if it idled for more than 5 seconds.
 

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YZFR6... ooodles of HP
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Air. Fuel. Spark. Not enough of any and it won't support proper combustion. Unhook the pc and see. But an ohm meter will tell you if a coil is definitely bad and causing intermittent spark and running rich thus fouling that plug.
 
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