bad gas & anti knock : V-Twin Forum: Harley Davidson Forums

berserker · 07-31-2007, 09:08 PM

Today drove about 50 miles, 90 degrees. Stopped for gas, as I was coming up to speed, 60, bike felt like it was cutting out, stumbling. Kinda reminded me a little of hitting rev limiter, but not as intense and not as long.

Felt weird, I actually pulled over to make sure tires were good.

I am thinking maybe over filled it and can't vent. Thinking all kinds of thing, is my bike gonna blow up. Going on trip this weekend Is my bike going to blow up.

I ride it home about 30 miles. About 5 miles from home heard a couple of the loudest pings I ever heard. And its still stumbling on acceleration.

So I siphon out some gas 2-3 gallons. Drive couple miles to gas station doing roll ons at 2500, no pings, cooler out now, 77.

Put 3.5 gallons. Got a couple lite pings still. I stumbled couple times to but not as bad.

Is this some kind of anti knock feature? When it cuts out.

I am thinking ride it tomorrow, for work. Every 40 miles put a gallon in. Got a job 80 miles away.

To complicate things further, Saturday, I installed SE AC and loaded what should have been map 159PZ004. Put about 200 miles on it since I installed. About 80 of them were pretty hot. Ran fine.

Pulled plugs before and after this, gray. No tan, but no white.

I am thinking bad gas, since it started right after gassing up. I thinki it was the 1st time I hit 60. Seemed to be alright under 3k, but 3-4k ran weird. At first I though my rev limiter was malfunction, cause it seemed to start stumbling as soon as hit 3k. Not every time, but a bit.

Got 2k+ trip this weekend. So this sucks.

Any thoughts? Bad gas and anti knock feature???

rmc115 · 08-01-2007, 08:54 AM

I am in the automotive field and we are seeing a lot of fuel issues now. ethanol is very common and picks up water. Just like the first time this was tried in the 80's, 10% works ok but sometimes it's not accuratley mixed and can be 30-50 ethanol which causes huge headaches. Hope that was it and you are fixed.

berserker · 08-01-2007, 09:37 AM

Quote:

Originally Posted by rmc115

I am in the automotive field and we are seeing a lot of fuel issues now. ethanol is very common and picks up water. Just like the first time this was tried in the 80's, 10% works ok but sometimes it's not accuratley mixed and can be 30-50 ethanol which causes huge headaches. Hope that was it and you are fixed.

I do run a bit of ethanol. but this was outside of the requried counties. Even had a sign we do not have reformulated gas.

What I wonder about is how long is premium sitting, now a days with the price of gas? It seems this year been having more pinging this spring. Down south, in May, I had less pinging, gas was cheaper, plus bikes had been running longer.

You got to wonder about the premium you get in the spring.

Sometimes wonder if better to just run 87, when you get in questionale areas.

On my stock 07, its probably ok to run 87??

My next build will be low compression and run on kerosene. Going to fill up every 40 miles today. Going to behot again so should be similar conditions, to see if something else.

berserker · 08-01-2007, 09:38 AM

Is there an anti knock feature and how does it work? Could find anything in ownder or service manual. But I though there was.

rmc115 · 08-01-2007, 11:17 AM

I run 87 unless it's above 90 degrees then 89 or 91 if needed. The spark knock was introduced as ion sensing technology that senses through the spark plugs. I am not sure how well it works but if you use aftermarket plugs or wires you get check engine lights.

BVBOB · 08-01-2007, 03:27 PM

I'm betting bad gas, ran 3400 miles plus last week from WI as far as Idaho and back and I can tell you all gas is not the same. Got one really bad tank at a Sinclair in Blackhawk SD, bike ran like crap until refilled, As for sparkplugs and the ion sensing anti knock, I have ran at lest 3 different brands with no issues and no codes, wires could be a whole new ball game though. Bad gas in the spring?, just watch the posts about pinging in this forum around April, that alone should tell you something. Dont really know of a decent octane boost that would not harm the 02 sensors on the 07 & 08 bikes.

berserker · 08-01-2007, 05:55 PM

Still bad. Almost seems worse after adding gas. Dislodging dirt?

HAs sometimes were it rides fair, but then other times were it stumbles quit a bit, mostly on acceleration, but sometimes when sitting at 60.

I raqn about a gallon last night. Drained around 2.5 gallons, and put in 3.5. Today I have add 4 more gallons, a gallon at a time.

Reading on how to dain the tank. With a carb you had one low spot with a screen, but sure here with the pump in the tank.

I can't beleive bad gas wuld go this long unless lts of crap floating in the tank. It has times were it kinda seems ok.

Supposed to leave Saturday morning for Sturgis then ND. As it is right now I can't. Drove 160 miles today. And about 30 last after filling.

berserker · 08-01-2007, 05:58 PM

Everything is stock accept, SE AC and map I added Saturday. Which I also wonder about. But I did about 80-100 this weekend, was cool out. The 110 yesterday, some was very warm no problem. All started after the fill up.

Also pulled over on the side of the road tday and pulled the vent tube under the seat off the check valve?. Though maybe vapr lock, when filling up. That didn't help.

berserker · 08-01-2007, 06:12 PM

Quote:

Originally Posted by BVBOB

Dont really know of a decent octane boost that would not harm the 02 sensors on the 07 & 08 bikes.

I have an unopened bottle of octane boost, I bough before gign to MT last time, but was able to get premium gas that time.

berserker · 08-01-2007, 07:42 PM

Well its all out. Couple buckets tubing, garden hose and 2 pairs of vice grips. Just got out of the shower.

YankeeBob · 08-01-2007, 08:32 PM

You running 93? I would also suspect your map.

berserker · 08-01-2007, 09:02 PM

Quote:

Originally Posted by YankeeBob

You running 93? I would also suspect your map.

Kind of afraid of that. But it didn't start until after I gassed up. I rode 50 miles before that in the 90s. 40 earlier in the day in 80s. And 80-100 over the weekend.

Funny thing is,it almost seems worse after filling up. I was putting gallon at a time in.

But it does seem to run fine cold too. So is it dirt settling or bike heating up.

This is a pisser. I got motel reserved,for this weekend no refund. Opening up the cnsole and looking in the tank. I got another fuel filter too.

berserker · 08-01-2007, 11:10 PM

Decided against doing filter. I lifted up the canopy. Looks like a screen on the bottom, that looks ok. Plus everything is crimped in there. Don't know if you want to put regular hose washers.

Got to be more then I wanted to do this time of night. Probably just wasted abunch of time and created possible other problems by opening everything up.

Should have justy drained it and refilled.

Is kinda cool you can access the tank through the top.

Might look into getting a crimper. Not sure where from.

berserker · 08-01-2007, 11:41 PM

Well it started, I am happy for that.

Got 160 mile ride tomorrow for work, going to be hot again. So same conditions, hopefully no problem.

The hot weather makes me think its tuning, but it didn't start until after I gassed up.

There was some black gunk in the filter on the funnel. But I don't know for sure where that came from. Thinks were flying, dropping, spraying, all over.

I weas going to run som gas in and out.. I already pushed it in the garage, and forgot.

berserker · 08-02-2007, 12:29 AM

I was starting to think, when I filled up, I was distrurbing dirt. It seemed wrose after fill up. But loking in there, it looks to be you wouldhave to have alot of crap to block that big screen.

Venting? I did remove vent frm check valve. Still did it.

Hopefully will ride out the job kinda early, before real hot then back in afternoon when hot. See if there is a difference.