Fuel smell

[Thunder]

on my 96 I have an issue with real bad raw fuel aftersmell. Last few days its been real nice so I'll start the bike up and let it warm up for a few min. After it warms up I kill the choke and it idles at about 1200 rpm and fuel smell is unbearable. I use premium gas no extra aditives, have new plugs n new air filter so I'm not sure if any of this caused it orsomething else possibly?


what could cause this and any known remedies??.

96 KATANA 750

[arsenic]

A lot of things could cause that. Your mixture is rich. You can lean it out by adjusting the A/F screws. Try that first. My second thought is that your needle jets are egg shaped. If that is the case, Buy some Factory Pro nickle plate emulsion tubes. Oh yeah, and GSXF engines are designed to use 87 octane fuel. You're wasting money.

[KAT TOY]

+1 on regular.

[Kreylyn]

My first guess would be a leak that is dripping out onto the engine and evaporating... you get the heavy fuel smell, but will never see it unless your looking real close.

Krey

[delbutler]

Is the engine being designed for 87 Octane fuel just for the US version of the bike ? Japanese petrol is 98 as standard as far as I am aware. In the UK it's 95 as standard and premium is 98. Therefore, wouldn't more UK and Japanese bikes exhibit these same symptoms quicker than US models ?

Was the engine or carb build altered slightly for the US to allow for 87 Octane fuel ?

[Wild-Bill]

The lower the compression, the lower the octane needed to avoid pre-detonation. You can still run higher octane, it just doesn't do any good.

[05RedKat600]

Is the engine being designed for 87 Octane fuel just for the US version of the bike ? Japanese petrol is 98 as standard as far as I am aware. In the UK it's 95 as standard and premium is 98. Therefore, wouldn't more UK and Japanese bikes exhibit these same symptoms quicker than US models ?

Was the engine or carb build altered slightly for the US to allow for 87 Octane fuel ?

The difference is Research Octane vs Pump Octane. In most countries, including Australia and all of those in Europe, the "headline" octane rating shown on the pump is the RON, but in Canada, the United States and some other countries, like Brazil, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI, and often written on pumps as (R+M)/2). It may also sometimes be called the Pump Octane Number (PON).

So, you need to check your pumps and see which number you use. Essentially, they are the same, just a different numbering system.

[Balindir]

just sayin my 94 was right on the frame sticker "RON 91 min" so idk?

[05RedKat600]

just sayin my 94 was right on the frame sticker "RON 91 min" so idk?

Yes, and here in the US we use the PON, or Pump Octane Number. 91 RON is about 85-87 PON. So yeah, just regular unleaded.

[Kreylyn]

just sayin my 94 was right on the frame sticker "RON 91 min" so idk?

From the Suzuki owners manual....

Fuel and Oil Recommendation

Fuel

Suzuki highly recommends that you use alchohol-free unleaded gasoline whenever possible, with a minimum pump octane raiting of 87 ((R+M)/2 method) or 91 octane (Research method). In some areas

and it goes on into oxygenated fuels and gas/methanol blends (in all caps DO NOT USE fuels containing more than 5% methanol under any circumstances....

Krey

[stoocats]

I used regular for quite some time, until I noticed a knocking or tapping sound when starting from cold. I changed to premium or higher octane and no more funny sounds when cold. Do my valves need adjustment or is the higher octane better medicine

[scottynoface]

I used regular for quite some time, until I noticed a knocking or tapping sound when starting from cold. I changed to premium or higher octane and no more funny sounds when cold. Do my valves need adjustment or is the higher octane better medicine

The higher octane is covering up the fact that your carbs are dirty and not getting enough fuel.

[05RedKat600]

I used regular for quite some time, until I noticed a knocking or tapping sound when starting from cold. I changed to premium or higher octane and no more funny sounds when cold. Do my valves need adjustment or is the higher octane better medicine

Adjusting valves isn't a bad idea. I would check the plugs in it as well....a PO may have decided to "upgrade" to a hotter spark plug that could cause knocking.