premium fuel bike got hot !!!

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Kickin_50
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premium fuel bike got hot !!!

#1

Post by Kickin_50 »

Hello , got the the '48 out yesterday ( bored 40 over ,cv carb ,straight drags , SPH still running points nothing fancy do not ride it hard at all) and put some non ethanol 93 octane in to freshen up old gas, Rode about 8 miles and came home, checking things out and bike was noticeably hoter than normal my pipes had blued down a lot further than they were, haven't got into it yet (sick to my stomach that I did some damage) started and rode fine oil levels were good. Just want to see If anyone else has any info or experience running premium fuel. I have heard to stay away from ethanol fuel eats carb parts and such and I did not think the difference from medium grade to premium was that big of a jump in octane . This is all pending on what I find out this week, as I get into it might not have been fuel at all . My other theory is the bike got real lean real quick ..... again fairly stock , TT bike not raw hided at all

P.S. pipes been on bike several years and no recent adjustments made.
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Re: premium fuel bike got hot !!!

#2

Post by panhandler »

I've run premium in my bike since day one, and I've had it over 20yrs. Never had a prob with overheating. std heads, jcam/Shorty E carb. does sound maybe running a bit lean? personally I wouldn't use any fuel older than 3 months, for the little cost it is to put in new....hope this helps.

keith
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Re: premium fuel bike got hot !!!

#3

Post by tomfiii »

Several causes are if running hydraulics,might have pumped up and left valves hanging a little/accidental alcohol from distributor/carb loose or developed leaks.
Mark44
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Re: premium fuel bike got hot !!!

#4

Post by Mark44 »

One of the first things to check is for leaks in the intake manifold. If it's sucking extra air in, your engine will run lean, which will make it run hot. I don't think your problem has anything to do with running high-octane gas. Also, if the timing is too advanced, it'll run hot as well.
58flh
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Re: premium fuel bike got hot !!!

#5

Post by 58flh »

If anything the premium will help & not hurt the bike!--Timing or VACUUM-LEAK! or both----RICHIE
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Re: premium fuel bike got hot !!!

#6

Post by Panhead Ed »

Did you have your timing pulled to the advance position ? retarded timing makes heat ...to much advance will make it detonate "spark knock "...and of course check for vacume leak.
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Re: premium fuel bike got hot !!!

#7

Post by VPH-D »

Sounds like your timer retarded itself a little. I've always run premium gas.
VPH-D
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Re: premium fuel bike got hot !!!

#8

Post by 1962FLH »

First if your fuel was old chances are it had time to gum up the jets in your carb just enough to cause a lean air/fuel mixture (motor hot). Second old fuel does not burn completely in the combustion chamber; meaning burning fuel traveling past the exhaust valve stem and down your chrome pipes causing them to get hotter than normal (blue pipes).
Higher octane! What does that do? Well in a high compression motor it does well; but in a stock compression motor all you get is a hotter running motor and no extra power. High octane fuel needs higher compression to completely burn in the combustion chamber.

What is Octane? Octane is a colorless flammable hydrocarbon of the alkane series, obtained in petroleum refining.
What does Octane do? The higher the octane number, the more compression the fuel can withstand without self-detonation (knocking). If your engine is not knocking you do not need higher octane. The relationship between the compression ratio, Timing and fuel octane level all need to be in tune for optimal engine performance. Once you determine the proper octane for your compression ratio and set your timing according you should stick with it.
Respectfully
John
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Re: premium fuel bike got hot !!!

#9

Post by 1951 adam »

I run 93 in everything , and your right , it's probably not needed....force of habit I guess. Check timing , jets, check for intake leaks. Was the bike performing correctly ?
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Kickin_50
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Re: premium fuel bike got hot !!!

#10

Post by Kickin_50 »

Thanks for replies , only got to pull the plugs last night , not moist but dark so bike wasn't super lean. gonna hopefully get deaper into it tonight . Thanks again for answers on premium fuel
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Re: premium fuel bike got hot !!!

#11

Post by awander »

High octane fuels do not run hotter. In fact, they "may" run cooler, see below.

The only thing that the octane rating tells you is how resistant the fuel is to detonation. This is typically only important in engines with much higher compression ratios than a stock or mildly hotted-up panhead.

If your engine has enough compression that lower-octane fuels detonate, you will get higher engine temps, and this may be alleviated by using a higher-octane fuel that does not detonate. But if you have detonation, you will have other problems, maybe before the heat gets you.

Just for reference, I have a copy of a survey of gasoline octane ratings done in the summer of 1952 by the Bureau of Mines, and the averages were 80.5 octane for regular-price gasoline, and about 86 octane for premium-price gasoline.

I have never understood why so many older-HD riders use premium fuel-seems to me to be just a waste of money.
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Re: premium fuel bike got hot !!!

#12

Post by Scrap »

I think we use high octane fuel because were old enough to remember when you could buy leaded or unleaded fuel at the same gas station. My memory is foggy but I think, for example, Sunoco 260, which was the high octane blend, still contained lead. We wanted the lead for our valves, not just the octane.
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Re: premium fuel bike got hot !!!

#13

Post by awander »

Another interesting fact is that modern gasoline contains little if any actual octane.

When they were establishing the ratings scale, a detonation resistance of 100 was assigned to pure octane, and gasoline and other fuels were rated on how they compared to that.
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Re: premium fuel bike got hot !!!

#14

Post by james »

My vote is for the manifold leak, air leak = heat.
Running with timing retarded = heat.

Jim
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Re: premium fuel bike got hot !!!

#15

Post by 58flh »

Andy---I think most of the guys know that running PREMIUM is not NESSESSARY with the LOW-COMP. MOTORS!///I ALWAYS run PREMIUM & never anything else!---My reason---It helps in cooler running-(If you ADJ. for a rich mix. & thats how I run mine).Also I run 4ozs. of MMO to every 5-gallons,ALWAYS HAVE & IT DOES WORK!--You can olny tell if you pull your top-end off every 2yrs. & I DO!.I also have a FACTORY SINGLE-FIRE IG now!/& will never go to singlepoint IG again!//Just so much more Balls in it & a LOPE that I never had before!--I Like to run ADV. some!/-So the Premium REALLY helps here in the form of ,NO PINGING--EVEN CLIMBING a HILL 2-up!--MEDIUM or SILVER GRADE 89octane PINGS on mine! & I olny have 8.5 to 1 slugs,It may be a smidge higher from Surfacing the heads all these years!.AT 92octane no ping!--I even throw Lead in my tank once a month with the MMO on a FILL-UP!.MY motor gets ALOT of use EVERYDAY for 8-months!--(use to be year-round!--But since Im getting older the WINTERS really kick my ass anymore).-Now my Brother with the 45 he runs the cheapest he can find!--with no problems at 5 to 1-comp.!---Im just saying there are reasons that some have to & NEED the 93 or more in there!.---Respectfully---RICHIE
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