Modern Vespa

I filled up my 500 last week with 93 octane (I'm in the US, NY). After reading about RON etc on another thread, I realized I made a mistake... The manual says 95 and I didn't know about the different octane ratings for other countries. I looked all over for 95 octane. I found none so I figured I'd just get the highest I could find which was 93. This was the very first fill up for the bike.

Anyway, the last couple times I took it out, I stalled at low rpm's. Twice at two different stop signs and once in front of my house when coasting into my driveway. Happens after it gets warmed up.

The bike only has 30 miles on it and I have never gone over 35 mph on it.
I still only have a learners permit so I can only take it out around my little neighborhood - small roads, slow going...

Could this stalling be attributed to the wrong octane fuel or the fact that I have never opened her up yet? I hope I have not damaged the engine by putting in too high an octane. Does anyone know if my engine's still ok?

Anyway, I'm FINALLY taking my road test tomorrow !! Can't wait to drive with all the grown-ups on all the 'big roads". Wish me luck. I'm actually a little nervous about the road test. I'm ready and all but I just feel like I'm 16 all over again getting my drivers license...

dk

Hi, this seems to be a common problem with the 500 during the break in period(650 miles) and sometimes(like with mine) a bit further. Here's the link to one of several post on it:
https://modernvespa.com/forum/topic36192?highlight=

My response is on there and I hope it helps as I, and I'm sure you as well, was kinda distraught by the stalling, thinking something major was wrong or that perhaps I had purchased a lemon.

Thanks for the reply. Anyone know if putting too high an octane fuel can damage the engine, cause stalling etc ?

dk

It won't harm the engine, it can cope with it. Occasional stalling issues are perfectly normal while the ECU 'learns' - and those who say it doesn't have a clue or two to find...

If the stalling issues still happen after the first 600-1000 miles then there may be some real problem, but this would be very unusual.

Thanks!

Oh and in the US we use R+m/2 which would be 91. In the te rest of the world they use RON not R+M/2 . So 95 RON is 91 R+M/2

Check this link out, http://answers.google.com/answers/threadview/id/334325.html

Wayne B

Stalling at idle, especially when hot, sure sounds like the missing fuel line clamps issue the BV500 and Scarabeo 500ie have had......which likely have a similar fuel system to the MP3 500.

http://www.apriliaforum.com/forums/showthread.php?t=153990

Just thinking.

Vernon

As you're in the USA it sounds like you are using higher octane gas than the minimum suggested by Piaggio.

If I was you I would try to honestly assess the performance of the bike from a MPG and ridability standpoint for both 91 and 93 octane and decide which is best for you. If there is no gain for more money stick with 91.

Thought I would bring this back up instead of starting a new thread...

If I had to consistently put the incorrect octane gas in my bike, which should it be? 89 or 93 ? Will it and can it cause irreparable damage to my mp3?
I've been using 93 octane for a while now. She's almost done with break in and has 575 miles on her with first service coming up soon.

I'm having a lot of trouble finding ANY gas stations around here (Yonkers NY)
that have 91 octane fuel!

I've checked, I think, almost all stations that are within a reasonable distance to my home over the last few weeks. Nothing... My choices are 87, 89 or 93 almost everywhere I go. One place has 92 but no credit card reader on the pump so it's a real PITA to gas up there. I want to avoid going inside. You know, lock up the helmet and gloves under the seat, answer tons of questions, etc... It's a rig-a-ma-roll... I just want to make it quick.

BTW - the stalling has stopped.

Dan-

Glad to hear the stalling has stopped.

I'm no expert on the fuel/octane thing, but I can tell you this: I'm coming up on 6K miles on my 09 500 and I've used the highest rating at the pump each fill up except for a couple. Everytime I accidentally went to the lower octanes, I had issues. Not necessarily stalling, but just slower performance overall, sputtering, and general acceleration and hiccups. So far, the higher octane which in this area of the country is usually round 91-93, has done the best. I may be oversimplifying things, but honestly I think you can just go to the super/highest grade at any American pumps and need not worry bout 1-2 octane differences over the long haul.

Thanks for the input! I too have noticed that the couple times I've put 89 in the tank there's been some sputtering when coming to stops and some flakey acceleration. I initially chalked that up to the bikes break in period... My instinct is higher = better. Don't know for sure though.

Dan-

"Minimum Octane Rating is 91"
So higher is better than lower.

Wayne B

We are having RON 92 and 97 here in Malaysia. I have been using RON 92 all the while and as of up till now, nothing bad have happen yet. Cheers!

Ok, thanks guys! I'll continue to stay to the high side of 91.

Dan-

Just look in the manual and see what the Octane Number you need it. Anything That number or Above is fine(IE if it says run 89 don't run anything lower then 89)Running Higher Octane doesn't hurt your Engine AT ALL. The only thing it does is it technicelly polutes the Air More because thoses Extra Octane are throwing into the Runoff of the Scooter. Running Lower Octane SHOULDN'T HURT THE ENGINE but you will see limited Performance.

Better use 93 than 89. In Europe 95 and 98 are standard on many pumps and 100 octane variations are usually sold under "high power " hype.
Most of standard engines will work fine with standard 95 octane fuel but high perfomance engines with compression ratio higher than 1:10 can have some benefits with higher octane fuel.


Check this video http://www.youtube.com/watch?v=dDHwCWdrtdg

You should be using the 97 if it's RON. You won't notice anything unless you ride it enough miles to burn and hole in the piston or burn a valve, but that can take 50,000 or 100,000 miles. Just depends on how hard the engine is working. Have seen high performance motors burn a hole in the piston in less than 20,000 miles using the wrong octane, 87 when min 93 was "required".

Wayne B

RON 92 will be just fine. The RON 95 is given as a target - but frankly these bikes can adjust to the different fuels and different altitudes, temperatures and fuels.

If they sold as low as RON 92 here I'd be using it too.

Just read in the news that we are gonna have RON 95 next year. Sold at the same price as the RON 92.It was written that RON or Research Octane Numbers refers to how resistant the fuel is to detonation or 'knocking'- higher numbers are more suitable for high-performance engines. And a question to jimc, you mentioned that if the have RON92 over at your place you would gladly use it. Any reason in particular? Price? Performance? Cheers!

Price - it would almost certainly be cheaper here. I do over 24,000 miles a year (pretty consistently), so fuel price is an issue, albeit a small issue.

I see. The price difference here between the two (RON92 and RON97)is 5%. If it is the same over there then you are able to get an extra of 1200miles per year. That would be half a month's fuel. Cheers!