wrong gasoline octane

[zero]

Hello,
So i had to add gas to the bike for the first time since I bought it, I went with 91 octane. Since then I've been having problems with starting and idling. Taking a closer look I noticed pinging too and back firing so I am assuming is the gas. If that is the case, should I keep driving it with the remaining gas or should I syphon it out? I just added about a gallon 89 octane

 

[jmink427]

I run 87 octane in mine all the time...

 

[zero]

thanks for your opinion, I don't know what the PO used, and after reading some of the post here a lot people were recommending 91 or 93 if available, anyways, I going to try 87 first then see how that goes then if problems then move to 89, thanks,

I just want to make sure i am not going to damage the bike with the wrong octane (ping and backfire).

 

[jmink427]

Hows is the timing? if you have to much advance it can cause the symptoms you describe also. I can put 93 octane in my Impala and it sounds like marbles in the header tubes cant even get it off idle barely but cut 110 with 93 50/50 and it does ok... Now I run it on E85 and will never go back to race gas as long as its available.... Impala 12 to 1 compression ratio..

 

[racerdave]

If it is actually pinging on 91, or 89, it will ping on 87 more. That being said, many places don't sell a lot of 91 octane. It can sit a while, and become worse than fresh 87 octane which is turned over more often. If you are buying ethanol based fuel, it degrades even faster. Phase separation. Where you are in Wisconsin you might be able to buy non ethanol, that would be my choice,

 

[zero]

don't know much about the timing right now, but one thing I can tell you is that I didn't have the pinging and the idling from cold start problems before I put the 91 octane. I know the bike could use a nice tune up since I just bought it, so you might be right, thanks

 

[jmink427]

detonation is never a good thing it can knock the ring landings right of the pistons and or bust them up.... Here is some pics of neighbors dirt track motor they ran 93 in and it needed race fuel.... the motor was 12 or 12.5 to 1... it's not pretty.......

 

[zero]

I think only some Citgo gast station have non-ethanol but I can give that a shot. I know if i go to kwik trip i can get 91 octane with no ethanol

FYI, pinging does go away when the engine is warm and idles nice after that

 

[retiredgentleman]

zero;

If the bike is new to you, and you are concerned about not damaging the engine, then you need to stop driving it, while you do some standard maintenance checks. Camchain tensioner adjustment, valve clearances, points gaps (if you have points), use a timing light to check the timing. You don't want the timing to go past the fully advanced mark.

 

[angus67]

does it ping underload? like when you take off, or does it do it idling? I dont know your skills, but if it goes away, your cam chain adjuster might need a look at. When these motors are cold, everything is kinda 'off' , if you know what I mean. then as they warm up, everything starts to jive together.

 

[zero]

thanks for the info everyone, the bike is running on original equipment, so it has pionts, which the PO said to me he calibrated
it does ping a little bit underload at first, but when the engine is warm no more ping!.
I think I am going to stop for a while and do a complete check,thanks. As far as my skills, I am more of a car guy then anything so this bike thing is sort of new for me(especially two stroke engines), but I was able to notice the ping so I am not that new, right? thanks

 

[Tomterrific]

Always run premium. The only thing teh octane number means is teh gas won't detonate as quickly as a lower number. I can get 93 for only 20 cents more than 87. Six octane numbers for 20 cents is a screaming bargain!

Time your bike with a light at full advance. A throttle blip above 3000rpm should have you well into full advance with points.

The XS650 is a 4-cycle engine just like a car engine.

Tom

 

[jasonslackisrad]

dump the gas or put some octane booster in it.

running lower octane gas will only make it worse.

its not that much more expensive for premium, just spring the extra 2 bucks. and don't go to shitty gas stations.

 

[zero]

Always run premium. The only thing teh octane number means is teh gas won't detonate as quickly as a lower number. I can get 93 for only 20 cents more than 87. Six octane numbers for 20 cents is a screaming bargain!

Time your bike with a light at full advance. A throttle blip above 3000rpm should have you well into full advance with points.

The XS650 is a 4-cycle engine just like a car engine.

Tom

Hi Tom, thanks for the info, now I feel silly for saying 2 stroke. I know I can get 93@ Mobil station other than that, here 91 is the highest. I am going to try to do a complete check so we'll see

 

[jd750ace]

Just my thoughts, if your low compression motor is knocking or pinging on 87 octane, at idle speeds, I'd be finding a cause instead of a band aid. That motor should run all day on 87, if it's healthy and tuned right.
Be prepared to do a top end at a minimum if you intend to ride around it. The machine is talking to you.
$0.02

 

[zero]

thanks jd750ace, for your opinion, as I mentioned before, I don't know what the PO was using for fuel, but that is not the point as you said. I may try an octane booster to see if that stop the knocking just so I can work on it, then I am going to get a manual and work on cleaning everything and setting the points, thanks

 

[pamcopete]

Wait, wait...I think we lost track of the original post. As I understand it, the engine was running fine until zero filled up with some 91 Octane fuel, so to me the only thing that means is the fuel is bad. Drain the tank and fill up with some high quality 91 Octane from a name brand station and not the one where you bought the bad gas. Be sure to drain the carb bowls as well and let the new gas run through the bowls with the drain open to purge the lines as well.

 

[zero]

Wait, wait...I think we lost track of the original post. As I understand it, the engine was running fine until zero filled up with some 91 Octane fuel, so to me the only thing that means is the fuel is bad. Drain the tank and fill up with some high quality 91 Octane from a name brand station and not the one where you bought the bad gas. Be sure to drain the carb bowls as well and let the new gas run through the bowls with the drain open to purge the lines as well.

Hi pamcopete, I know Im going to try a different gas station for sure but I would like to make sure that the timming and everything elese is correct. My course of action is to stop riding the bike, drain tank, put new fuel from a different gas station, check carbs, thanks

 

[Tomterrific]

A fellow in teh industry once told a group never to fill your tank while the tanker is topping the station tanks. The fuel from the tanker can stir up any sludge in teh bottom of teh station tanks and pump it right to your vehicle. Makes sense.

Tom

 

[XS1961]

Some of our supermarket petrol quality is pretty bad here,causes all kinds of rough-running, Ive learnt which to stay clear of now..