hello
i was playing in the snow today and noticed when i was going up hill in first gear the engined seemed to miss a few times. nothing major but i kind of heard a little pause or stutter in the engine. the spark plug is almost brand new. i use only hi test fuel. any ideas?

also, that darn bolt on the bottom of the exhaust pipe, the one you can loosen and clear some of the carbon out, well mine is on forever i guess. ive tried, the shop has tried, the local mechanic has tried. now its pretty much rounded. does anyone routinely loosen this bolt to clear the carbon. any ideas on how to get the bolt out? we have tried running the engine and getting the pipe hot, but that didnt help either. who in the heck at honda dedided to put a brass bolt there??? awful soft. not dissing honda, i love em but just question the brass bolt.
thanks for reading
sean
union, wv

 

ok... hi test fuel? isnt that what people used to call high octane? if so, that could be your problem....

High octane does not mean high-performance. end of story. High-octane burns slower and is harder to ignite. That way you can put it in a true high-compression engine and it will resist detonation from the heat of the higher compression that regular octane fuel would normally pre-ignite under. That way, the fuel is ignited by the spark plug at the proper time, not early. Putting regular octane in the same engine would cause loss of power (lower octane burns faster, easier to ignite, lights off too early) and possible engine damage ( holes in/ cracked pistons)

Putting high-octane in a low compression engine will not be as bad, except that todays higher-revving engines have only so many milli-seconds for the fuel to completely burn. A slower burning fuel doesnt make sense, now does it? What happens to that extra fuel that didnt burn because it burned too slow? It turns to carbon. it cakes itself to the combustion chamber and exhaust. How much? depends how long. some engines dont build up a lot, some do.

I see you have a rancher ES. That is a low-compression engine, around 8 or 9:1 compression, not nearly enough to even run mid-grade, and certainly not high-octane.

If you constantly run high-octane in you machine, it's possible for it to become addicted to it. The carbon will build up in the combustion chamber and actually raise the compression ratio. Then you would need high-octane just to make it run right. But it wont, all that carbon interferes with the engine's ability to breathe.

The best method is to find the lowest octane that the machine runs on without detonation or "pinging". That way you know you have the fastest burning, most volatile fuel that the engine will tolerate without loss of power or damage.

With all that said, I hope you fix your problem.

 

whoa dude

didnt know that about hi test fuel. the owners manual says to use something like 90-93 unleaded(like super at the pump). so if i have been using this higher grade fuel for 2 years and switch to a lower grade gas like 89 how might effect the engine? should i stay with the 93 grade or start using a 89 grade. also, do you have any idea how i might get that plug out of the exhaust pipe?
thanks for the info- in this case i though that the higher price gas (93) was better. i need to find my owners manual but i thought that is what it said to use
thanks again
sean

 

Stripped Bolt Removal:
At your local auto parts store, they have an internal extractor. It will be like a socket (used with your ratchet) that has tapered, spirowed (sp) ridges that grab a rounded off bolt (or nut).

BTW, brass is used so that it may be easier to remove than steel bolts. I know. Things don't always work as designed...

 

My 2005 rancher's owners manual says 86 octane minimum, and regular around here is 87. You should consult your manual, but i dont see why it would be any different, mine is a 350, i'm pretty sure yours is too, if it's just an ES. I run 87 all the time and havent had it ping once on me yet.

another thing about high octane fuel or "premium" as it's called around here, is that the majority of todays cars use 87 and due to the fuel injection, nobody needs premium. So it sits in the underground tanks at the filling station and doesnt get used, and it gets old. This is especially bad in remote places, like northern Minnesota where i ride most often. The regular octane fuel is used the most, so the tanks go empty more often, get filled more often, and doesnt have a chance to get old sitting in the tanks.

You should drain your tank and try regular once. If the engine makes noises it hasnt made before, then go back. If it sounds fine, then run it on that and see if your stutter goes away.