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Where did you get such crappy pump gas? I've driven across the country multiple times over the last 20 years and have never gotten bad pump gas.
Santa Paula. We have a plane there so I can drive right up to the pumps, but you can park in the parking lot by the restaurant and carry a couple metal cans in. It’s a short walk to the pumps. 4.89 a gallon yesterday. Don’t think you’d get hassled.
Or specially made fuel that is double the price for that matter....
Point is, if its going to happen you may as well saved enough to rebuild your bike by using pump gas instead of race gas anyway.
If you are trying to make a 125 a 250f beater then yea, go wild. But I have seen so many dudes put VP or whatever in thier stock 450s, then complain about the sport being so expensive that I am unsure if grown adults are able to put two thoughts together.
lol this thread is about crappy race gas that is wrecking fuel pumps and causing runability issues and you bring up the thought pump gas at a tenth of the price is the issue?
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You grenaded an engine due to your lacking ability to tune an engine, dont blame the pump gas bro. 30 years of riding and racing on pump fuel and ive never come across this "crappy pump fuel" you speak of. My oldest son has won 8 off road championships over the last 9 years, all on wawa (NJ convenience store) 93 octane.
I cant tell you how many people think they NEED to use VP in their bone stock 250/450 four strokes, the ignorance is mind numbing
I need it
https://www.airnav.com/fuel/local.html
Anyone foul a plug using AVgas in an EFI bike?
I did once but it was also really cold. The plug had a weird matte coating on it. Looks like the lead could have accumulated on the plug.
Been using EF91 since then, no issues at all.
Here's a map to find EF gas.
https://www.pure-gas.org/
My Yamaha fuel injected bikes never fully warm up if it's below 60 degrees ambient. I actually installed a thermostat on them to make sure the engine gets out of the cold enrichment setting. I'm surprised more people don't do it since they're so concerned about maximum performance they're paying for race gas 😂
Interesting that I was on a Yamaha when I fouled the plug.
19-23 yamaha 250f's are notorious for fouling plugs even on pump gas. I believe that they are just way too rich in cold weather and it boils down to the rider. Ive had countless customers come in with a bike that stopped running and it turned out to be a fouled plug, but i never witnessed it in real life until we had a 2021 that i sold with 115 hours, it never fouled a single plug during my ownership. I sold it to a father who wanted a reliable bike to ride with his kids, it was the dead of winter. Sure enough, the first time he rode it, it fouled a plug. He never went past quarter throttle that day, and i happened to be there to witness it. It was mind blowing to see an EFI four stroke foul a plug, a problem ive only ever seen happen on this gen yz250f
I was wondering if anyone else had encountered odd behaviors out of VP fuel lately. I've been running T2 in my YZ for a couple years, never had a problem. I filled up with the T2+, and started having some odd issues with starting, and stalling. Drained it, filled it back with 40:1 Sunoco 110, and the problems vanished. I'm curious to see if it's just a bad batch, or if these new blends just aren't all that great.
Yes whatever the issue is seems to be both T2+ and T4+
Mine is in shop now, new fuel pump, clean throttle body, inspect valves, hopefully all good after that.
You are correct. Still half in the engine masters car engine mindset. I forgot we are applying it to dirtbikes lol.
I guess I mean that if you run lower octane than the engine requires, it may pre-detonate (which will decrease power) and may not run for vey long. lol.
Pretty common with snow bikes of every brand, it's why thermobob exists (the company that makes the thermostats for dirt bikes).
One of my off-road race buddies could "cold seize" his 81 or 82 YZ 125 if it was cold outside. He put on a T-stat.
Not sure what the difference was, I never had it happen on my Hondas. Closer piston to bore tolerance?
Oh, and it was Texas, so not THAT cold.
The ktm tbi bikes have tstats and people like to take them out.
I swear my 4t ktm would make oil in the winter but not summer. Those don’t have tstats.
Pit Row
Factory installs thermostats for the bikes to run correctly and designs them to run on pump 91. Customers remove the thermostat and run VP racing 100 octane fuel that destroys the bike...
I bet none of the current 4 strokes get above 150° riding at any speed when it's cold outside. The 2 strokes run cooler so they definitely need thermostats. When everything was carbureted it didn't matter as much.
Ktm 125 carb bikes came with plastic radiator blockers for cold weather. I think the partial block was supposed to go on at around 55f
If you're "making" oil in a 4t engine in cold weather, it is likely due to fuel in the oil because of enrichment or iced intake.
Happens in atv's and sxs's that plow in the winter.
I had a generator intake ice up, causing rich condition in -30F while ice fishing. I checked the oil when I woke up to it running poorly and the oil shot out the fill hole LOL
I suspect enrichment which is controlled at least in part by coolant temp I think.
My dealer just informed me that there is in fact a recall on T4+. No certain batch number they said just anything bought within the last 6 months. I have 2 bikes down currently and now wonder if that's my issue. ONLY reason I've ever bought VP is to make sure I'm running good, clean consistent fuel. Unreal
Anyone ever heard of Fuel Factory? Our Fuels – Fuel Factory I tried searching the forum with no results.
Huh, never saw those. We ran our KTM125 race bikes down to 20f on numerous occasions at the Woodland Winter series and all I ever did was rejet to add more fuel with the cold dense air. We did make sure to warm the bikes up well in the morning. Ran 92 EF blended with VP110 and never had any issues even when racing in the snow. Bikes absolutely ripped in the cold weather. My FC250 and 350 never had an issue either in that cold, same fuel mix (w/o the smoker oil of course!).
I'd never heard of them.. quick Google search shows positive results mainly from drag car community. Not to much from moto crowd. Their mxr 4t is their T4+ equivalent. Looks a little cheaper too. I'll have to look into a bit more, thx.
Sigh.
You know what they say about assuming…
This was a bone-stock 250 2 stroke, carb (not EFI), five rides old. Fuel was 91 pump from a name-brand/top tier, busy station. Oil was also a name-brand motorcycle premix at the recommended 32:1. What no one knew or could have predicted was that oil companies had just started blending ethanol and/or other things into fuel at the time to make it more “green” friendly. It just so happened that these wouldn’t blend well with synthetic premix oils, and would separate. In my second moto, the additives (now devoid of oil) resulted in my bike seizing as I was shifting down the start straight.
Kindly explain how the $&(% I was supposed to anticipate the fuel blend changing unexpectedly, and tune for it/switch oils/etc?
I have run race fuel ever since. Until now, it meant that I no longer needed to concern myself with fuel as a variable. I didn’t do it because I need more power, thought race fuel would make me faster, etc.
Oh, and you’re right, I don’t know shit. After all, I’ve only built multiple car engines, and have been building/rebuilding motorcycle engines since I was 15.
I truly don't believe that premium pump gas has a higher chance of being 'bad' than race fuel. Look at how many vehicles they have to serve with pump gas. There would be a lot of people with performance cars with a lot of claims against the refining companies if that were the case. There is a lot more cars on the road with a 91 octane requirement than dirt bikes. I have heard it once, and the gas station got inspected and it was found they had a hole in the tank and water was getting in. Look at the number of reports on bad race fuel just in this small community thread. My local gas station has 94 at the pump so that is my go to.
I believe issues with race fuel being used in a 'normal' motor and fuel system is going to cause more issues than 'bad' pump fuel ever would. And look at this thread...
Brings me to another point. Do you guys that are running race fuel clean the fuel out every time you ride? Once a week? Once a month? Never? How long do you leave it in the tank and fuel system?
I doubt the gas was the reason your engine blew up. I've run lots of ethanol blended fuel with zero issues on my premix bikes and jet ski.
I've never had an issue on my 2T or 4T runing 2 gallons of pump premium with 3 gallons of sunoco gtx or 50/50 using gtx plus, runs me about $35-40 for 5 gallons and has dyno'd out well on all my built motors and stock motors. I've done back to back vs straight t4 and the difference was negligible at best.
I honestly feel like people are sleeping on pump sunoco fuel.
Do peole really have issues with ethanol? I have never had a bike or someone ive helped bikes have issues. Straight pump gas in a bike and carb multiple times for months drained it and bike ran fine. Had a 250f that sat for over a year with the gas on to the carb, drained it filled it up let it run out of the drain for a minute and it ran fine. Its honestly just something maybe im lucky but never had an issue with.
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