Question about Bike's Year and Fuel used

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D-Max2012

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Question guys.
The Clymer manual for the 91 states that the bike is recommends regular fuel, and no higher ethanol use than E10.
It seems that the majority of people are running high octane.
Can you post your year and fuel type use?
 
Use regular. Stock motor does not need any higher octane. Year doesn't matter. Runs better with recommended octane. Don't understand why many waste their money for poorer results.
 
I've been running 87 Octane in my 2000 for over 12 years now.
I figure the engineers at Yamaha knew what they were talking about when they recommended 87 Octane.
 
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This label is under the seat in plain view on my gen two. I never run regular because it says 91 MINIMUM OCTANE
 

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Use regular. Stock motor does not need any higher octane. Year doesn't matter. Runs better with recommended octane. Don't understand why many waste their money for poorer results.
+1 . Regular(87) is just fine. Just treat with Seafoam (or equivalent), if you are
going to lay up the bike for more than a month or so. Better still, fill the tank with non -ehtanol gasoline, and start and warm it up at least once a week.
Just what has "worked for me"
Cheers!
 
I'm wondering which Octane Rating, matches more closely to the regular O.R. Yamaha designed Gen1's to run on. We now have an additive that alters that number. Ethanol.
 
87 in my 85 I found a gas station that sells regular 87 octane but it's 20 miles away and almost .23 cents more then ethanol . Must be cause their close to summit point raceway wva . I'm going see if running regular improves performance and mileage .
 
I'm going see if running regular improves performance and mileage.

This is the primary reason why I posted this question.
Many people, on an individual basis, believe that running premium is always the best bet. But, unless a specific question is asked, Year of bike and Fuel used, an individual may be misinformed. Spending more money for less performance.


I've spoken to many mechanics and they all seem to agree that you need to know the model year, and manufactures recommended fuel.
 
They manufacturer will post the fuel the bike needs under the harshest conditions. Meaning the hottest it will get and under the heaviest throttle loads. The higher the octane fuel the harder to ignite and the slower it burns. You want to run the lowest octane you can get without detonation. This makes the most power (and efficiency).

Even 1428 and 1500 engines will run fine on 87. Long rod or high compression engines should consider the 91 as the standard fuel unless the tank of fuel they will be running is used for normal driving around. The demands on the fuel will be far less and even octane of a much lower rating would work.

The gen 2's will also run on standard 87 fuel with no problems. (detonation). But, if you're going to be racing it or in conditions that will get it at the hottest levels AND racing it then you for sure want the higher octane fuel. Even the reflash takes advantage of advancing the timing curves to put more strain on the fuel so the 91/93 fuel will work better in those conditions. BUT, still - for normal riding even with that flash work the 87 will still work just fine (and run cleaner with better economy).
 
I've been trying to pin down this annoying lag around 4K-5K in 4th gear around 60-70 MPH. Above that RPM the bike pulls like the beast it is. Below that range, and its smooth sailing.
I've cleaned my carbs 4 times (last with an ultra-sonic cleaner), came out looking great.
Set float levels to 17mm below center mark. Put jets to factory. Synced carbs, Coated tank (no more rust), Checked vacuum and compression - all to spec, new carb boots, no leaks on other boots, new battery, charging system to specs. There are two things I’m looking at now.. 1) if the plug wires are leaking spark to the engine body when it gets to that RPM range, or 2) I've used premium since I got the bike last year and never tried regular, as recommended in the Clymer manual.
 
Usually the best thing for a 4-5k lag/stumble is to shim the needles, by putting a thin washer under the clip to raise the needles a wee bit.
 
Usually the best thing for a 4-5k lag/stumble is to shim the needles, by putting a thin washer under the clip to raise the needles a wee bit.
Would you know how thick of a shim?
Going to the next slot on the needle might be too much. I think the spacing is something like 1MM apart. FP needles.JPG
 
I'm creating some right now.. Hopefully I can try them by the weekend.
 
Just in case anyone was wondering, the needles blunt end is 3.0mm in diameter. So your shim should be at least 3.2mm Inner Diameter x .4mm thick. 6mm OD or less should work fine as a shim.
 
There is a vmax guy (Paul) that makes precision made shims in 1/2 and 3/4 thickness's for more fine tuning.

Sean
 

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