[Petros Tsialiamanis]

Hi, my motorbike started stalling. It is a Yamaha YBR 125cc model 2016 with 6100miles
In a distance of 10km it stalled 6-7 times. On the first 1-1.5km there is no problem but after that it starts stalling. The feeling is like I have a high gear ie 3rd or 4th and low speed. It "kicks" for 10-20secs and If I don't give more throttle, it stalls. I can start it again immediately. Any ideas/suggestions?
I am new here and I am not familiar with many of the terms.

 

[johnnyvee]

Hello Petros,

Welcome to the forum. I'm not an expert, but since nobody else has responded, I'll try to help.

My first suspect for the problem you describe would be an issue with the fueling system. Does your bike have fuel injection or a carburetor?

Removing the spark plug and inspecting it, (and posting a picture once your are permitted) will help to diagnose the issue.

 

[WintrSol]

Next time it stalls, open the fuel cap, and listen for a small whoosh of air. If you hear even the smallest air sound, your tank vent is probably blocked. This is especially true if you can go farther on 1/2 tank than a full tank, as it takes longer for the vacuum to build up in the tank.
Next, check the battery Voltage, to see if it is being kept full by the charging system.

 

[ZephyrRider]

I think guys above has right about it's a problem in fuel system. About valve/vent in fuel tank cap - you can check it by ride with not fully closed cap (safety first - not recommend to do it on public road).

Next, I suggest to check petcock. If you have a classic petcock try ride on ,,res'' set - especially if there is a pressure controle valve. If stalls disappear on res set it could be problem with this valve. Ofc something can block fuel flow - rust from tank bag etc.

 

[WintrSol]

That's a thought - if you have a vacuum-controlled fuel valve, it may have a 'PRI' setting, which bypasses the control valve to prime the carbs (assuming it has carbs). If you have this setting, and it no longer stalls set to 'PRI', then the vacuum side of the valve is the problem.

 

[ZephyrRider]

I had thought about ,,PRI'' but wrote ,,RES'' . Sorry for mistake and WintrSol thanks for correct my answer.

 

[Petros Tsialiamanis]

Thank you all for the replies. I went to a garage and they fixed the issue.

-Ignition switch was intermittent due to salt corrosion
luded the ignition switch/worked in.

- Spark plug cap faulty/poor connection.
Fitted a new plug cap.

 

[Critter]

Thank you for the follow up letting us know what the problem was.