StromTrooper banner

Mileage and Cams

3K views 9 replies 7 participants last post by  trex 
#1 ·
Ok, I've searched, I've looked at VSRI and I haven't found a decent answer. I did my valves on my K8 Vee. Put the bike back together and mileage is down from a consistant 39mpg to 31mpg. One thread:

http://www.stromtrooper.com/dl-1000-%5B-vee%5D/54888-poor-gas-mileage-2.html

Suzikawa says:

"Turn the crankshaft to align the "F|T" line on the generator rotor to the index mark of valve timing inspection hole & the exhaust cam lobes should be
at the 3 O'clock and the intake cam lobes should be at 12 O'clock position exactly from the right side of the bike.

If the intake cam lobe is instead at the 11 O'clock or 1 O'clock position then it is off by a tooth..."

I took a look at the rear intake cam an adjusted to his recommendation and no noticeable difference in mileage. Is this guy full of it? My bike seems to be running fine whether I was off by one tooth before or off by one now. It starts right up, pulls pretty smooth. If my rear intake cam is or was off by one tooth what difference should I notice in the way it runs AND what will happen to my poor engine if it is off by one tooth?
 
See less See more
#2 ·
The manual contains the correct procedure for timing the cams -- use the timing marks, not vague landmarks like "3:00".

That said, it's usually pretty damn obvious when you're off by a tooth. I haven't mistimed a Vee, but engines generally are hard to start and run like total poop if the timing is off. I think you'd notice this before you left your driveway.
 
#3 ·
If your bike is running fine, I too find it hard to believe the cams are not in time. I have not run a Vee with cams out of time to be certain, but the car engines I had to diagnose sure didn't run....fine!

Don't know what might be wrong with your fuel mileage, I was getting 34 on my Vee most of the time. If I thought it was the cams, I would have sure looked into it though. Let us know what you find.
 
#4 ·
I would have to agree with the other responses however it's possible that with two independent cams per jug, one tooth off on one cam could produce loss of mileage with little other effects. As previously stated, one would think you could hear and feel a difference though. Depends on weather it was the Ex. or In. cam and if it was retarded or advanced and how much overlap it created. Mileage loss occurring immediately after adjustment more so suggests that either correct procedures were not followed during inspection and r & r or vacuum lines or sensor connections were dislodged or forgotten during re assembly. Interested in knowing what you find out though!
 
#5 ·
I don't have experience with timing being off a tooth on the Vee but I do have plenty of it on a 450 MX bike.
A single cylinder will be harder to start and run awkward (less a better description) however, it will run. Fairly obvious something's wrong.
A twin with one jug being good, I would imagine it less noticable the other cylinder being off a tooth.
 
#6 ·
Waiting Game

Okay, so I am off one tooth on the rear intake cam. I know this because I set it closer to '12 0'clock' or one tooth away from where the manual says it should be. The bike starts fine and is running fine too. I am pretty busy with work so I am going to have to wait a minute before checking what the mileage is with the cam adjusted this way. I also find it interesting that it is running fine when it is indeed off. Once I get a mileage check I will dig back in and set the cam right. One other possibility is that it looked one tooth off but when I torqued it back into place and did not check it again before I put the cover on... it may actually be in the correct position. I'll update with mileage numbers and pics sometime next week, I have Monday-Wednesday off.

Separate rant - If the post that I quoted is total trash I think someone, someone with credibility, should say so in that thread...just sayin.
 
#7 ·
cam timing is off. This happened on a buddy of mines bike. He went from 40's, to high 20's.:confused:

He went back in and corrected this, and back to the 40's again. Not sure how he got it off, but is was during a valve adjustment. I have always been lucky and set every thing back in the same, I guess:thumbup:, Now I know that I need to pay better attention to that:mrgreen:
 
#8 ·
There is a bottle of nail polish in my garage.

No, it is not for those moments when I need to feel pretty. :mrgreen:

It is for those moments when I need to paint match marks on cam sprockets and cam chains.


There's also a big can of hair spray on the shelf. It's for installing grips. Really.
 
#9 ·
Also, nail polish remover or acetone, mixed 50/50 with ATF, is the best penetrating fluid for seized parts.
 
#10 ·
Ok, so I'm gonna fix my cam timing this weekend, maybe. Then I put on some nail polish and pour the remover in my clutch mc and the ATF in my gas tank. Got it. Oh ya, and the Arrogant Bastard Ale in my tummy. Sound like fun.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top