[raymondleuk]

Hi all, i recently bought a Benelli Tnt25 with decent miles with a good price, was told that there was problem with the bike so i thought why not, with a cheap price and with some effort, there goes a fun bike to ride around.

*it is a FI bike

The problem I'm encountering at the moment is
1) When i start the bike, i need to give it throttle to start, pushing the starter button alone would not start the bike, but only cranks it
2) When the bike starts, it would not run smoothly on idle, it runs low on RPM and i need to give it throttle to keep it running, if i let go the throttle, i would die
3) When i put it into first gear, and slowly let go the clutch, i stalls on me everytime unless i keep it revving

Things i have done
1) Engine Oil
2) Coolant
3) Spark Plugs
4) Fuel Pump
5) Fuel Filter
6) Battery
I have not replaced the air filter yet, i just blew it with an airgun

I'm lost at the moment, send help...

 

[Aussie Steve]

Run some good fuel injection cleaner through it. Make sure the tank vent is working. Also check there is no build up of crud in the tank....any in there will have got sucked through the pump and injectors causing problems. You say you did the pump but what did you do....a thorough clean is often next to impossible to do as the internal filters are non serviceable.

You could try to reverse flush the pump if you suspect it...often a pump out of the tank situation.

If you can find out the value for the TPS, (Throttle Position Sensor usually near the injector/s) then a multi meter check is a good start point.

Make sure there are no air leaks...also try running it without the air cleaner to see if it will run better.

Finaly there will be sensors for air intake temp etc that control how much fuel is injected...working like a choke so if you can locate them check to see if they are firmly connected...specs will be needed for testing.

Good luck

 

[raymondleuk]

Run some good fuel injection cleaner through it. Make sure the tank vent is working. Also check there is no build up of crud in the tank....any in there will have got sucked through the pump and injectors causing problems. You say you did the pump but what did you do....a thorough clean is often next to impossible to do as the internal filters are non serviceable. You could try to reverse flush the pump if you suspect it...often a pump out of the tank situation. If you can find out the value for the TPS, (Throttle Position Sensor usually near the injector/s) then a multi meter check is a good start point. Make sure there are no air leaks...also try running it without the air cleaner to see if it will run better. Finaly there will be sensors for air intake temp etc that control how much fuel is injected...working like a choke so if you can locate them check to see if they are firmly connected...specs will be needed for testing. Good luck

I suspect it’s the ignition coil, did some testing on it with a multi meter, can’t seem to get a reading, it should be 3-5 ohms, but I only got 0.1 I changed the fuel filter and pump to a new one, seems like that’s not the problem, but it’s a better upgrade

 

[Easy Rider]

Make sure there are no air leaks...also try running it without the air cleaner to see if it will run better.

Your description sounds a lot like a vacuum leak around the intake.

To verify that "not enough fuel or too much air" is the problem, you can carefully spray a little starter fluid into the intake.
Propane works good for this too.

Any chance that the exhaust is plugged up ?
Or that it has been modified by removing the muffler ??

 

[raymondleuk]

Your description sounds a lot like a vacuum leak around the intake.

To verify that "not enough fuel or too much air" is the problem, you can carefully spray a little starter fluid into the intake.
Propane works good for this too.

Any chance that the exhaust is plugged up ?
Or that it has been modified by removing the muffler ??

Nope, the exhaust system is original, never removed, at least that’s what I heard from the last guy haha

 

[Easy Rider]

Nope, the exhaust system is original, never removed, at least that’s what I heard from the last guy haha

Your answer focuses on the LEAST important part of my comments.

How old is this bike ?
Old mufflers sometimes rust out the baffles and they collapse in a way that blocks the exhaust flow.

 

[raymondleuk]

Your answer focuses on the LEAST important part of my comments.

How old is this bike ?
Old mufflers sometimes rust out the baffles and they collapse in a way that blocks the exhaust flow.

I do actually smell some weird smell coming out from the exhaust, it kinda smell like burnt petrol, so I’m guessing it’s too much petrol?

this bike is from 2016 and has 28k km on it

 

[Easy Rider]

I do actually smell some weird smell coming out from the exhaust,

It could be a dead rat that you smell. Seriously.
But you should not guess. Some tests can be done.......as I already mentioned.