Stelvio struggle, won't rev over 5000 rpm

[kgujas]

Hi to everyone,
My name is Kristijan , I am a new over of a 2011 Guzzi Stevio Ntx, small tank .
Engine has now 55000km and it is rollerized .
Yesterday when I was driving , the engine wont go over 5000rpm . If I open the throttle at that rpm motorcycle start to slow down ...
Till 4500-5000rpm everything seems fine, engine pulls nice , no struggle ...
Please help , where to start ?
Thanks .

 

[scottmastrocinque]

You should first perform a Throttle Position Sensor (TPS) reset.

This requires an electronic tool to do this.

 

[kgujas]

Thanks for fast answer ,i will post the results here.

 

[V700Steve]

I don't know how long it's been like this?
Worth a look at the cam timing. Specially if it's been this way since rollerazation. One tooth off will cause this issue and most likely the RH side. Dead center TDC is almost in between 2 teeth. Close enough that more than a few have been found.
Easy fix if that's it.
Worth checking the valves in case they are tight, pull covers & look at sprocket.

 

[kgujas]

Hi,
I have some news ... I have started with valves and they are tighten to much IN about 0.03mm , EX about 0.06mm . I also run into a problem that 2 adjustment nuts can't be tightened it seems that the thread in those 2 nuts are bad .
That nuts are M6x0.75mm ?
Also what is the recommended gaps between the valves, in 0.10mm or 0.15mm and ex 0.15mm or 0.20mm ?
My engine number starts with AC with rollers, small tank .

 

[Paul_Tim]

Small tank, Rollers, I run in 0.1 and ex 0.15mm and have done for 40K miles, no problems and rarely have to make any adjustments.

 

[kgujas]

Hi, finally I have some update...
I was waiting for valve adjuster screws and nuts 4 weeks. After I got them I adjust the valves , do a throttle bodies balancing , TPS reset.
After that go to test ride and more or less the Guzzi struggles the same way . After test ride I connect the Diag and from failures I read this P0352 Coil right : to high . Maybe my trouble is with coil and I need a replacement ? From bad coil can motorcycle struggle like I described earlier ?

thanks.

 

[Paul_Tim]

Many things can cause this, wiring, the coil itself. I've attached an extract fron the service manual about this error code.

 

[scottmastrocinque]

Coils do not have moving parts. They have two windings and the standard failure is the wire breaks or burns out and has a continuity failure.

Coil failures cause the motorcycle to stop dead. They don’t come back from this without a new coil. I suspect your error is erroneous due to poor battery condition.

Also, GuzziDiag is an EXPRESSLY FORBIDDEN topic here as stated in the 3 rotating screens above the 3 dots at the top of the page.

Also, that software will eventually bite you in the ass and quite possibly brick your ECU. I would not recommend it.

What I suspect more than anything is a clogged fuel filter inside the fuel tank.

At 11 years and 55,000km, it needs to be changed and I suspect it hasn’t.

If it is indeed clogged as I suspect, then the large demand for fuel which occurs at that higher RPM, will be unfulfilled resulting in the precise symptom you are experiencing.

There are only 2 reason why an otherwise competent engine doesn’t run correctly, spark and fuel. You are obviously getting spark but not enough fuel.

This all hinges of course on the belief that you have not gone messing with your fueling settings with that damn GuzziDiag program. If you’ve gone and done that, well then you have created your own misery and nobody here can get you out of that hell.

 

[kgujas]

Hi, sorry for GuzziD... I will not mention it again .
I do not mess with fueling , so I will start with spark plugs because it seems to me that are old , then I try with fuel filter in the tank .
It is a small tank Guzzi, so can I change only the filter and what filter I need for replacement ?
Thanks.

 

[scottmastrocinque]

SEARCH is your best friend. You cannot just rattle off question after question. You must search and read.

The fuel filter is part of the fuel pump assembly but it can be changed out. There is also a nylon sock filter at the bottom of the pump but those can usually be cleaned with some cleaner and an old toothbrush.

I believe you will also need to have a new gasket ready for the sealing of the fuel pump to the tank. You need to search and read.

I know the STORE has all metal filters

All Metal In-Tank Fuel Filters

All-metal Fuel Filter - Includes New Fuel Line Clamps The half plastic/half metal in-tank fuel filters from Guzzi are not rated for any standard unleaded fuels, much less those with ethanol. Replace it before it separates and strands you. Used on most all modern in-tank fuel pump F.I. Guzzis...

gtmotocycles.com

I would recommend searching Stelvio Fuel Filter Replacement and reading the information. Then, if you get stuck you can post a specific question then.

 

[john zibell]

what filter I need for replacement ?
Thanks.

Since you aren't in the US, a KL145 fuel filter or equivalent. It is the same fuel filter used in early BMW K bikes.

 

[kgujas]

Hi , finally I have a good news ...
I have replaced the fuel filter and clean the fuel tank and my Moto Guzzi now goes how it should , no more struggles ...
The problem was in clogged fuel filter . Thanks to everyone for helping and thank you scottmastrocinque !

 

[scottmastrocinque]

Честитам! Нема на чему.

Outstanding! You are most welcome.

I’m very happy you found your issue.

Best Wishes.

Знати један језик није довољно.