elus1ve
Member
A month or two back there was a post about hesitant cold engine. For as long as I can remember, I always had this problem and since that post I have been watching for this engine behavior even more closely. Coincidentally the problem got gradually worst since I started watching for it (I did ask another rider to confirm the engine hesitation for me just to make sure I was not imagining things).
Initially, when the engine was under 80deg celcius, the engine would hesitate when revving under load. Nothing I couldn't live with and I actually thought it was normal before. As it got worst, the engine would sometimes be unwilling to rev higher than 6000rpm and I would have a rough idle. So this got me worried and started checking TPS and vacuum but nothing.
I then did an engine cleaning treatment with Seafoam and the engine got a lot worst before it got better. The first tank with seafoam saw my engine dying by itself when idling on multiple times. So the treatment was definitely doing something so I did a second tank with the product and then it gradually got better until the engine got back to how it was before and when cold it would hesitate less than before and no problem at all when warm, but the problem wasn't gone completely. It was starting to become an annoying random problem. The treatment led me to believe that it was a problem with fuel delivery and I was recently told my engine runs lean.
I was considering leaving it at a shop but in the end I did find the issue and... it wasn't the bike. I simply started refueling at a different gas station and boom no more hesitation. I get my gas at the same gas station most of the time and it would get mixed up with gas from other gas stations from time to time, hence the reason why the behavior would seem random. Avoiding my one usual gas station and the problem is no more. I went back to my usual gas station to confirm and the next morning the problem occurred again.
Now what could be the reason? I stayed with 87 Octane when switching to other gas stations so it is not an Octane issue. I don't believe in higher octane when not required by the engine and I am not going to name any brand here as I don't believe in any major benefit by switching from one brand to another. My dad was in the petroleum business for years and for him gas is gas; and the advertised chemicals have negligible effect and are used as marketing tools, and I tend to believe him. The kind of issue I had with the gas is due most of time to the quality of storage and transportation according to him. Probably water or impurities in the underground storage of the gas station. He has seen gas stations where the underground storage had cracks and allowed water/impurities to get in gradually. This is usually not big an issue enough to warrant major renovation work but it would mean the gas would be of lesser quality, specially after a refill from the truck where the impurities at the bottom would get disturbed by the flow of new gas. I'm planning to try gas from the same brand at another station just to confirm the theory. I might also keep refueling my car at that gas station as my car uses 91 Octane and these are held in a separate storage compartment.
All this to say that you should try a different gas station if you are having engine hesitation
Initially, when the engine was under 80deg celcius, the engine would hesitate when revving under load. Nothing I couldn't live with and I actually thought it was normal before. As it got worst, the engine would sometimes be unwilling to rev higher than 6000rpm and I would have a rough idle. So this got me worried and started checking TPS and vacuum but nothing.
I then did an engine cleaning treatment with Seafoam and the engine got a lot worst before it got better. The first tank with seafoam saw my engine dying by itself when idling on multiple times. So the treatment was definitely doing something so I did a second tank with the product and then it gradually got better until the engine got back to how it was before and when cold it would hesitate less than before and no problem at all when warm, but the problem wasn't gone completely. It was starting to become an annoying random problem. The treatment led me to believe that it was a problem with fuel delivery and I was recently told my engine runs lean.
I was considering leaving it at a shop but in the end I did find the issue and... it wasn't the bike. I simply started refueling at a different gas station and boom no more hesitation. I get my gas at the same gas station most of the time and it would get mixed up with gas from other gas stations from time to time, hence the reason why the behavior would seem random. Avoiding my one usual gas station and the problem is no more. I went back to my usual gas station to confirm and the next morning the problem occurred again.
Now what could be the reason? I stayed with 87 Octane when switching to other gas stations so it is not an Octane issue. I don't believe in higher octane when not required by the engine and I am not going to name any brand here as I don't believe in any major benefit by switching from one brand to another. My dad was in the petroleum business for years and for him gas is gas; and the advertised chemicals have negligible effect and are used as marketing tools, and I tend to believe him. The kind of issue I had with the gas is due most of time to the quality of storage and transportation according to him. Probably water or impurities in the underground storage of the gas station. He has seen gas stations where the underground storage had cracks and allowed water/impurities to get in gradually. This is usually not big an issue enough to warrant major renovation work but it would mean the gas would be of lesser quality, specially after a refill from the truck where the impurities at the bottom would get disturbed by the flow of new gas. I'm planning to try gas from the same brand at another station just to confirm the theory. I might also keep refueling my car at that gas station as my car uses 91 Octane and these are held in a separate storage compartment.
All this to say that you should try a different gas station if you are having engine hesitation
