Power loss

[MIG]

Update: during todays ride with full tank symptoms ocurred several times, but less obvious, drastic. Just barely a loss of power for a second. Turned throttle and all was well. Riding behind me you would not know.
Called dealer and explained. He asked how full do I fill the tank. Said he has seen this a number of times in the summer when hot, people fill too much, expands, gas in canister, vaccum lines. Said if this is the reason, just ride and it will clear out.
I have overfilled several times.
Consistent with symtoms diminished.
Said could take several tanks to totally clear out.

Reminds me of my 2008 America... had similar issues in the summer if I overfilled the tank.
-MIG

 

[GPMAZ]

Update: during todays ride with full tank symptoms ocurred several times, but less obvious, drastic. Just barely a loss of power for a second. Turned throttle and all was well. Riding behind me you would not know.
Called dealer and explained. He asked how full do I fill the tank. Said he has seen this a number of times in the summer when hot, people fill too much, expands, gas in canister, vaccum lines. Said if this is the reason, just ride and it will clear out.
I have overfilled several times.
Consistent with symtoms diminished.
Said could take several tanks to totally clear out.

Not that I'd ever advocate doing such a thing, but, I believe you can remove that canister. Not sure how smart the new ECU's are, but I know it worked on older models without a problem. Or so I've heard.

 

[JPHDT]

I could be wrong but I experienced such a phenomena with a bike and a car. If it is not possible for air to replace the gas in the tank when the tank was initially full, the engine can get some issue (not enough gas). When it appears, stop riding, open your gas tank to let air going inside then restart and check if it appears again. If it woks try to have some air able to go inside your gas tank (cap) when riding. Hope you can understand what I mean. I apologize in advance for my bad American...

 

[MIG]

I could be wrong but I experienced such a phenomena with a bike and a car. If it is not possible for air to replace the gas in the tank when the tank was initially full, the engine can get some issue (not enough gas). When it appears, stop riding, open your gas tank to let air going inside then restart and check if it appears again. If it woks try to have some air able to go inside your gas tank (cap) when riding. Hope you can understand what I mean. I apologize in advance for my bad American...

Yes, tanks are vented. If the venting is not working properly (i.e. blocked or clogged) a vacuum is created. This also happens when a tank is overfilled; caused by the expansion of the gas as it heats up. I'm no expert; I've just experienced this in the past...
-MIG

 

[GPMAZ]

Yes, tanks are vented. If the venting is not working properly (i.e. blocked or clogged) a vacuum is created. This also happens when a tank is overfilled; caused by the expansion of the gas as it heats up. I'm no expert; I've just experienced this in the past...
-MIG

+
Exactly. Back before those environmentally friendly canisters were introduced tanks just vented under the bike. My previous, un-environmentally friendly solution just connected the tube exiting the tank to another tube exiting under the bike, bypassing the canister altogether. Again not something I am recommending and its likely illegal in many jurisdictions.

 

[maurice]

I think I nailed the problem after 4 tanks of gas and no symptoms. My covered parking spot is on a hill! Kickstand side the low side. Full tank, then was parking it. Changed parking to facing uphill. Who knew!

 

[Azisbest]

Great news!

 

[maurice]

Great news!

Love good news!

 

[JPHDT]

I think I nailed the problem after 4 tanks of gas and no symptoms. My covered parking spot is on a hill! Kickstand side the low side. Full tank, then was parking it. Changed parking to facing uphill. Who knew!

I could be wrong as my English is not good, reading your description, I am thinking to this:
1) first case: tank full, air from outside cannot go inside the tank. The internal face of the tap is only facing gas.
2) second case: tank full, air from outside can go into the tank when you park as the internal face tap is facing air both sides. Then air pressure in the tank can quietly be adjusted during parking.

To check that you could park the bike case (1) with only 1 gallon in the tank and check if you have any issue when you restart.

That means for me, that it is good to check gas in the tank by opening the tap before any ride . You are sure that pressure is in equilibrium with outside.

 

[maurice]

I could be wrong as my English is not good, reading your description, I am thinking to this:
1) first case: tank full, air from outside cannot go inside the tank. The internal face of the tap is only facing gas.
2) second case: tank full, air from outside can go into the tank when you park as the internal face tap is facing air both sides. Then air pressure in the tank can quietly be adjusted during parking.

To check that you could park the bike case (1) with only 1 gallon in the tank and check if you have any issue when you restart.

That means for me, that it is good to check gas in the tank by opening the tap before any ride . You are sure that pressure is in equilibrium with outside.

Greek to me but I appreciate the thoughts. Pretty sure resolved.