[gischethans]

I am facing a strange issue with our TVS Wego. I mostly kickstart it and it starts in one or two attempts the first time. However, after turning off the engine for some quick stop en route, it becomes extremely hard to kickstart i.e., the vehicle doesn't start at all. Even self-ignition start takes a few long attempts. This problem started after full service including battery replacement about two months ago. I took it to the same mechanic but he said it can happen occasionally but in my case, this is happening two out of three times. What could be the reason?

Another trick someone suggested was to park on the centre stand, accelerate a bit (this is normally not required at least for our scooter) and then kickstart. Then the scooter starts instantaneously. Is this approach harmful?

[Rahul Bhalgat]

Originally Posted by gischethans

I am facing a strange issue with our TVS Wego. I mostly kickstart it and it starts in one or two attempts the first time. However, after turning off the engine for some quick stop en route, it becomes extremely hard to kickstart i.e., the vehicle doesn't start at all. Even self-ignition start takes a few long attempts.

As the engine consumes the fuel from the tank, an equal volume of air must be able to fill-up the volume emptied by the fuel inside the tank. A vent in the fuel tank lid allows this. If this vent is blocked considerably, a vacuum will be created in the tank as you drive and it won't easily allow the fuel to flow to the carburetor.

To check if this is happening:
When your scooter refuses to start after turning off the engine, open and close the fuel tank lid once. Try to kickstart the scooter then. If it starts immediately, then the problem is with the vent. Any local mechanic will clean the vent open.

[gischethans]

Originally Posted by Rahul Bhalgat

When your scooter refuses to start after turning off the engine, open and close the fuel tank lid once. Try to kickstart the scooter then. If it starts immediately, then the problem is with the vent. Any local mechanic will clean the vent open.

So the problem occurred a few times but the procedure didn't help. Guess something else is wrong.

[srini1785]

Originally Posted by Rahul Bhalgat

As the engine consumes the fuel from the tank, an equal volume of air must be able to fill-up the volume emptied by the fuel inside the tank. A vent in the fuel tank lid allows this. If this vent is blocked considerably, a vacuum will be created in the tank as you drive and it won't easily allow the fuel to flow to the carburetor.

Originally Posted by gischethans

So the problem occurred a few times but the procedure didn't help. Guess something else is wrong.

What @Rahul has suggested is what came to my mind too. Since the procedure does not help, the problem must lie somewhere else. Have you tried starting with choke closed?.

[gischethans]

Originally Posted by srini1785

What @Rahul has suggested is what came to my mind too. Since the procedure does not help, the problem must lie somewhere else. Have you tried starting with choke closed?.

I tried with the Choke and without it but that didn't make a difference. What puzzles me is the first start of a day happens in a single or at the max two attempts but later (like just two minutes after a stop) it's a hassle to start the vehicle.

[bamaboy]

Check the Ignition Coil. Problem might be occurring due to no spark. Our Office Activa had the same issue.

[srini1785]

Originally Posted by gischethans

I tried with the Choke and without it but that didn't make a difference. What puzzles me is the first start of a day happens in a single or at the max two attempts but later (like just two minutes after a stop) it's a hassle to start the vehicle.

As you said, the battery is only months old, I am discounting it. You can check for spark strength by the normal method. Just disconnect the plug from the engine , connect the plug to the plug cap , place the plug in contact with the engine body and kick start the bike. It must be a clear strong spark every time you kick.

I am not that familiar with Wego, but with Activa or Jupiter , when you are starting, you should have the brake ON. If the ON switch is having some problem, the bike wont start. The wiring diagram given below is not of Wego but of Access 125 which is similar to Wego and the image is taken from TBHP itself. If any of the starting conditions are not met, there would be no spark or very intermittent one.

Originally Posted by gischethans

Another trick someone suggested was to park on the centre stand, accelerate a bit (this is normally not required at least for our scooter) and then kickstart. Then the scooter starts instantaneously. Is this approach harmful?

I did not follow, how would you accelerate if the bike does not start?.

[gischethans]

Originally Posted by srini1785

I am not that familiar with Wego, but with Activa or Jupiter , when you are starting, you should have the brake ON. If the ON switch is having some problem, the bike wont start.

I did not follow, how would you accelerate if the bike does not start?.

Yes, the brake should be on even on Wego.

By accelerating a bit, I meant to twist the accelerator while kick starting. While doing this, the brake need not be used. That gentleman who suggested this approach while I was struggling to start the scooter, mentioned that holding the brake is required only when using self-start.

Thank you for sharing the diagram. I will go through it for better understanding of the internals.

[srini1785]

Originally Posted by gischethans

By accelerating a bit, I meant to twist the accelerator while kick starting. While doing this, the brake need not be used. That gentleman who suggested this approach while I was struggling to start the scooter, mentioned that holding the brake is required only when using self-start.

Have you tried it?. Ideally the bike should not start. This being a CVT gearless bike, its damn dangerous to start with a pulled throttle cable. It would send you and the bike off to a flying start .

On a center stand its different.

Originally Posted by gischethans

I will go through it for better understanding of the internals.

If you see the diagram, there is something called as carburetor switch, frankly , i have no idea what it is but I am guessing that it is some kind of sensor to check if the throttle is in idle position and not pulled while starting. If this sensor is faulty then too the bike would not start. Notice that this switch is in series with the ignition coil. I have marked it for you.



All the best.

PS: God i love those old analog bikes without any sensors and likes. I have said this before too.

[gischethans]

Originally Posted by srini1785

Have you tried it?. Ideally the bike should not start. This being a CVT gearless bike, its damn dangerous to start with a pulled throttle cable. It would send you and the bike off to a flying start .

On a center stand its different.

Yes, I have tried it. The bike starts instantly every time if I do that.

[srini1785]

Originally Posted by gischethans

Yes, I have tried it. The bike starts instantly every time if I do that.

Bit puzzled. You mean the bike starts with pulled cable while on a center stand and it does not start while the tires touch the ground with the same pulled cable condition?.

[gischethans]

"You mean the bike starts with pulled cable while on a center stand" - Yes, that's right.

"It does not start while the tires touch the ground with the same pulled cable condition" - No, in this case I don't twist the accelerator. I mostly hold the left brake and either kick start or self-start. This is where the problem occurs with both kick and self, especially after the vehicle is stopped for a while on the way.

[srini1785]

Originally Posted by gischethans

"You mean the bike starts with pulled cable while on a center stand" - Yes, that's right.

Guess that solves the riding problem. Just put it on the center stand, start it, bring to idle and go. Not possible every time i know.

Originally Posted by gischethans

"It does not start while the tires touch the ground with the same pulled cable condition" - No, in this case I don't twist the accelerator. I mostly hold the left brake and either kick start or self-start. This is where the problem occurs with both kick and self, especially after the vehicle is stopped for a while on the way.

The more i think of it, it seems to be a brake switch related problem. If it were the plugs it would not start at all.

No harm in slightly twisting the throttle cable and starting with the self start with brake ON and then OFF. The clutch does not engage up to a certain rpm.

Does the center stand have any switch?.

[gischethans]

Originally Posted by srini1785

No harm in slightly twisting the throttle cable and starting with the self start with brake ON and then OFF. The clutch does not engage up to a certain rpm.

This is good to know. I think I will follow this approach.

No, the center stand does not have any switch. But it's pretty smooth and easy to park on a center stand whenever there is hard ground. Dad finds it difficult though.

I think the next time I take it for service, I will ask the mechanic to investigate this brake switch.

[ashwinprakas]

Originally Posted by srini1785

If you see the diagram, there is something called as carburetor switch, frankly , i have no idea what it is but I am guessing that it is some kind of sensor to check if the throttle is in idle position and not pulled while starting. If this sensor is faulty then too the bike would not start. Notice that this switch is in series with the ignition coil. I have marked it for you.

It's the TPS.

I had a look at the GS150R's wiring diagram the second line that goes to the Ignition Coil is from the TPS, same colour code as the Access as well albeit a bit rudimentary.

From my experience with my Wego the one on the TVS motorcycles are a bit more advanced than the typical ON/OFF type switches.

As for the issue at hand my best guess is its fueling related, scooters do have a vacuum operated fuel tap which is a PITA.

Provided the consumables have been timely changed do have a look at the carburettor.

A reading of the spark plug would give you a clear picture of how the engine is running.