Worst gas milage EVER !!! plus the fumes issue continues

[ChrisM]

Hello VRs... I need some advice.

Some time ago I posted a question about possible exhaust leak and got many responses there ... thanks again for that.

While I did run couple of seafoam bottles through my RSV to get rid of that exhaust smell, it helped a bit but did not fix it completely.

Now as the title of this thread says, I just experienced the WORST EVER gas milage on my bike since i got it last year...

I had only 226 km (140 miles) on the odometer when the low fuel light came up. I went to the gas station and filled 16L (4.23gal) of gas.

Recently I had the 25000 km service done by the local Yamaha service and I was told that it is in perfect condition and there is absolutely no problems or issues with the bike.

 

I still have the same problem with exhaust fumes... just after the short 15 minute ride to work the lower part of my jeans smell like exhaust.

I have two sets of pipes, the OEM and BUBs, but it doesn't really matter which ones i use... the result is the same.

I have tried to look around for any cracks or holes or anything along the entire exhaust, but was not able to find anything.

And now that milage...

 

Can you guys throw some ideas/pointers???

I'm slowly giving up

[Flyinfool]

That is 33 MPG, while not great mileage it is not that terrible or unheard of either.

I have gotten down to 80 miles on 4.5 gallons which is about 18 MPG. My full size 4X4 pickup does better than that. That was 100% due to riding 80 MPH into a 40MPH headwind pulling a trailer with temps in the 90s. Next tank I slowed down, made the turn to cross wind and was back to normal 38 MPG. There was nothing wrong with the bike, just the way I was riding it. Point is it could be the way you were riding and/or weather conditions contributing to the low mileage.

 

As far as the smell, what do your plugs look like? Do they say you are running way rich?

[RedRider]

I would look at three options to fix this:

 

1) Float bowl fuel levels. The 2nd gens are notorious for having fuel levels too high in the float bowls. Check in the tech section for procedure to properly set.

 

2) Carb mixture. There is a fuel mixture screw on each carburetor. If never adjusted, they will be covered with a small brass cap. They should all be set the same (mine are at 1.75 turns) and then the carbs resynced.

 

3) Double check that your carbs are seated correctly in the boots. My bike never ran right when I first had it (9000 miles on it). When doing my first valve check (and setting float bowl level), I found the one carb I could never tune properly had the boot lip turned under creating a vacuum leak. When the carbs were reinstalled correctly, it tuned up and ran perfectly.

 

Good luck. Let us know what you find.

 

RR

[ChrisM]

To say the truth It is pretty hot here this past week... high 30s celsius...so maybe that is the reason.

I did not check the plugs... they were replaced as part of the recent service and the service guy did not mention anything about them.

[Flyinfool]

You have enough miles on to have the plugs show an indication of mixture. It is actually better to be reading clean new plugs with low miles on them.

 

Hot temps reduce available horse power because the air is less dense, this usually mans that you will pull the throttle open a little farther to get the same acceleration that you are used to, and less dense air means that the engine will run a little richer.

[YamahaLarry]

Yeah, something doesn't sound right if you smell like exhaust. I, for the most part, run my 99 RSV practically every day on the interstate at avg of around 80mph. A couple weeks ago, I make the 15 mile ride between 95 and 105 mph most all the way, chasing an idiot young lady that tried to literally run me over at 70 mph. I wanted to express my thoughts to her and she tried to outrun me in a Gallant.

 

Anyhow, I record every expense, including fill ups, and keep a running record of mph current, month, year, etc, and my average over the last 13k miles or so is a little over 38 mpg. Sometimes I had 42+ mpg, sometimes 36 or so, and never have I smelled like exhaust.

 

I would think that you are definitely running on the rich side for some reason.

[ChrisM]

Thanks guys for the hints.

First thing i will check the plugs for any signs of running rich.

if that's not it then I will be looking for some fellow VR members living close by that would be willing to help me do the stuff that RedRider mentioned.

[Ace]

I have had the same issue with 2 RSV's, on my '06 (in about 2009) and on this 2000 which happened last season. I could smell rich exhaust when riding plus I could smell raw gas when I'd let off the throttle when I was on the highway. On both bikes eventually liquid fuel started coming out of the carb vents. The fix was to rebuild the carbs as the O-rings that seal the float valve seat to the carb body were failing causing the fuel to bypass the needle and seat and overfill the carb bowls. Another thing to look at is the O-rings on the pilot mixture screws, mine were deteriorated badly and this will also cause a rich mixture plus leak externally. If you use some harsher cleaners in your gas the rubber parts will deteriorate, they will deteriorate with age as well.

Just posting my experience....

[Condor]

I wonder if this has something to do with the ethanol they've been putting in the fuel??? Might be something we all need to be aware of....

[RoyalRider05]

I had the same issue....i ended up doing this.....doesnt smell anymore and tons of power.....

 

http://www.venturerider.org/forum/showthread.php?501-The-Jason-Mod

[Rick Haywood]

if i am running interstate speeds 75-85 mph by the speedo I go to reserve at around 140 miles myself so it all depends on where you are riding. On 2 lanes just riding around at lower speeds I have went has far as 200 miles before reserve

[MikeWa]

Sorry. Double post.

 

Mike

[MikeWa]

Short rides with idling equals poor mileage. In that case 33mpg is not that bad. Pushing high speed or into wind also causes poor mileage. Again 33mpg might not be that bad. Before doing any work get a base-line mileage at freeway speed of about 60mph. Do this for a couple of trips. Watch out for wind as it can skew results. Then as you make repairs or modifications you will have something accurate to compare with. Anything over 40mpg is good. Of course higher is better.

 

To do a really good job of setting the carbs up a gas analyzer is needed. Four of five gas is best but a two gas will work in a pinch. Most motorcycle shops do not have this tool so mechanics are guessing. They are adjusting by ear and rpm but that still means guessing as to whether everything is ok. A good knowledgeable mechanic with a gas analyzer would pick up exhaust fumes in an instant and be able to track down the problem. Unfortunately I do not know of a single motorcycle shop using this technology.

 

Mike