2017 Vertgio 250 suddenly running very rich

[dowsonm]

I’ve had my 2017 bike from new and never had any problems - still on the original 9V battery!

However, when I got the bike out yesterday for the first ride in a few weeks it would start OK but would not run smoothly.  It felt as if it was running very rich, it wouldn’t rev very cleanly and then struggled to tick over.  I checked the plug and it was very black.  Also quote smoky when it was running.  Vertgio UK weren’t sure what it was but clarified that the TPS sensor failure usually makes the bike very lean, so unlikely to be that.

Am about to book it into a dealer for a check, but has anybody got any suggestions?

[Tiewrap]

You adjusting the TPS u can make the bike rich or lean.

Wich also means that when it fails or changed setting the bike can become rich or lean.

My first guess would be TPS, if the fuel pump fails it would be to lean.

[dowsonm]

Thanks Tiewrap.  Is replacing the TPS quite easy to do or are any special tools needed for set up?

 

[Tiewrap]

Officially u need to set it with help of a computer I suppose. To reach it is a bit fiddly, but not difficult in my opinion (remove water pump). On my i have set it so that the bike runs fine, simple as that. Can be handy to have a bolt in it which u can turn by using a hex key with round head, that way u can adjust it without dismantling the bike.

Short answer : yes, no special tools needed.

U could try measuring with an ohm meter if the value changes when turning the TPS. I could not find values in the manual quick.

[peterb]

It is possible that the motor is drawing in gearbox oil, possibly through the crankcase LHS. There may also be signs of gearbox oil escaping externally, have a look behind the flywheel.

[dowsonm]

Thanks Peterb, that sounds quite likely as there was more exhaust smoke than usual.  Will check it shortly.

[peterb]

On those earlier Vertigo's, there is little mating surface in the crank case area and quite easy for a few big knocks to jolt the two halves and create a leak path. If that is the case and the crankshaft seal has worn then you could be drawing in gearbox oil. You can leave the motor in the frame, turn the bike upside down, remove the clutch and strip off the lower crank case "half" We used Loctite Greymaxx as the sealant. Also need to bung up the vent in the fuel cap. Bye, Peter B.

[dowsonm]

I think the oil leak is the problem. This is what I found when I removed the flywheel cover!

[Tiewrap]

Oh my !

That's not a little bit. Can u update on how the repair is going ?

From what I understood the lubrication of the bearing is pressure feed. Which means there is a seal on both sides. U might just have another problem instead of a solved problem.

 

I am very curious if this story is right. As I "heard" this, so I do not "know" this.

Edited April 4, 2022 by Tiewrap

[dowsonm]

First thing I need to do is remove the flywheel but am not keen to pay 120 Euro for a Jitsie tool so need to make one and have ordered the metal today.  Will then strip the engine in the bike if possible.

[peterb]

Those flywheels are on real tight, when you make the puller (I used a flange with 3 x M8 socket head bolts with a threaded insert), make sure the bolts go a long way into the flywheel, get a lot of tension on and tap/smack the end of the centre extracting bolt head to break loose the taper. On the older motors, there are no pressure fed bearings, just gravity fed from the gearbox. Check the LHS crank bearing has not failed, you would have heard a rumble by now if it was.

[dowsonm]

Thanks for this advice.  Hope to build the puller this weekend and have bought high tensile bolts that can be threaded as far as possible into the flywheel.