6G Poor Mileage / Excessive Fuel Usage - Thoughts?

Hi folks -

2002 VFR800 non-abs w/ 54,000km. PCV w/included 02 eliminators, Autotune (installed but did not yet get around to enabling and trying it), PAIR delete / blockoff. Flapper / snorkel eliminated, Leo Vince slipon system. Bike has run excellently since I got it 4 or so years ago, including with the PCV and Flapper/snorkel delete.

Last winter I did the PAIR blockoff plates (using RTV to seal them, I destroyed the rubbers while farting around trying to get those little bast*rd screws out before I read about the vice grip method), removed the plumbing, and installed new OEM spark plugs ($). Also added Leo Vince slipon system.

I know and expect that I will smell extra gas fumes with the PAIR delete - this was the case, no problem.

However I found my mileage was down significantly - I can't say exactly how much (set my SpeedoDRD incorrectly after a gearing change, so the mileage reading is off) - but lets say 150km / tank where previously it was 250-300... so it was significant.

The bike also felt like it was lacking some pull... it ran properly, did not feel like it stumbled or misfired, VTEC engagement was fine, temperature display was fine - but it just didn't feel like it was pulling as hard as previous, the exhaust was really stinking like fuel, and also perhaps of note is that I swear the bike itself is getting hotter than it used to (*temp reading is normal, but the frame really seems to heat up and I think its more so than previous - hard to say with certainty though).

Since it ran OK, I didn't do any real troubleshooting, and I really didn't ride it all that much last summer. I want to deal with this now though - looking for assistance?

I have read up on FPR failures, as this seemed a potential suspect - now my bike hasn't run since November, so I think it was fairly optimistic to pull the FPR vacuum line and hope to see fuel in there - but take a look at this pic, the tip of nipple on the "T" had a shiny coating that smelled like fuel when I rubbed it off with a Q-TIP. Actual vacuum line itself appears to be bone dry; I blew some compressed air through to make sure its not plugged (its not), and no fuel or anything came out.

[image: post-25792-0-69414600-1459606072.jpg]

Also, potentially of note, when I opened up the airbox I see this from what I believe is the crankcase breather (stuck a Q-TIP in this too and it appears to be a light spray of oil, so I don't expect it is a problem but figured it was worth a pic):

[image: post-25792-0-55454800-1459606461.jpg]

Any input, suggestions, tests you think I should do - let's have it, I want this solved. Reality is that my bike is currently in storage (with full access); I can move it to an area where I can start it but it will be a PITA so any thoughts on things which should be tested without actual running would be preferred :)

Sorry for the long post, but I wanted to get all of the pertinent info out to minimize the back and forth... so now I say... HELP!

Mike

Was the change immediately after working on the bike? It is unclear if the change was due to something you did, or if you are just mentioning your work on the bike and the problem happened sometime after that. If yes then there is little chance something went bad at the exact same time. Reverse your steps and check your work. Double check the spark plug part number. Are the plug wires on securely? Are they on the correct plugs? Your description of heat made me wonder if gas is igniting in the exhaust, radiating heat from that unexpected area.

I know you said you cannot run it now, however a next step may be to run it when you can and check the temperature of all of the exhaust runners. A variance can tell you if one or more cylinders are not firing.

What fuel map are you using? Did you change to an appropriate stock map with the exhaust change? A change from stock to aftermarket muffler usually means running leaner overall, so this would typically cause the opposite problem from what you are experiencing. Just mentioning it as a point of reference.

Regarding your concern about heat: So the temperature is the same for the same? Did you flush the coolant? Only if yes I am wondering if you introduced air into the system. Otherwise check the service manual for testing the coolant temperature sensor.

Smell the oil and check it's level. The bike should be straight up or on a center stand. If it smells like gas and the level is particularly high that may indicate, like you were alluding to, a leak. If the FPR is good maybe a fuel injector is stuck open.

Edited April 2, 2016 by Knight

Also a stuck T-stat that prevents the bike from fully warming up will cause it to run rich and burn more fuel.

After you check out other options I would suggest you activate the Auto-Turn feature so it can do what it's designed to do. Then again anytime your have issues and a Power Commander or similar device is installed, I would always unplug it and set the bike back to stock and see if the issue disappears.

Good luck.

BR