Engine rpm drops too low at stop/idle

[MotoGuzzi750]

For last week or so, I noticed engine rpm drops too low, and recently rpm drops so low and the engine shuts down, unless I keep turning the throttle at stop.

What could have caused this?

- bad air filter?
( have not looked at air filter, so not sure how good or bad it is )
- does the throttle body needs cleaning?
Is there a procedure somewhere which I can follow if this is needed.
- how significant is air screw setting in this case?
I mean could air screw be big part or
Not so big part of this engine dying situation?
Both air screws are not fully closed, I am reasonably certain.

Sorry forgot to add model: Its 2004, Breva 750 IE.

Thanks.

[guzzisteve]

What model? Breva 750? Got a manual? 

https://guzzitek.org/gb/ma_us_uk/750/Breva750IE_042003_Atel(GB).pdf


Air filter & Throttle body cleaning are important, air screws also. Equally L & R at 1/2- 3/4 open. I do my EV every 10K mi

[lucky phil]

For last week or so, I noticed engine rpm drops too low, and recently rpm drops so low and the engine shuts down, unless I keep turning the throttle at stop.

What could have caused this?

- bad air filter?
( have not looked at air filter, so not sure how good or bad it is )
- does the throttle body needs cleaning?
Is there a procedure somewhere which I can follow if this is needed.
- how significant is air screw setting in this case?
I mean could air screw be big part or
Not so big part of this engine dying situation?
Both air screws are not fully closed, I am reasonably certain.

Thanks.

Here's a tip when looking for troubleshooting assistance. The symptoms are one thing but other salient information needs to be included some of which is listed below. Your issue could be many things but answers to the following will sure expedite the troubleshooting assistance.
Exactly which model and year bike are we talking about?
Is the bike ridden regularly?
How many klms/miles on it?
Has it just come out of storage or been parked for a significant length of time?
Did you just refuel it before the issue?
Did you just recently wash it or ride it in a rain storm?
Is it serviced regularly?
Has it just been serviced/worked on?
What was the very last thing done to the bike before the issue?
What weather conditions are we talking about and does it have the issue when the engine is hot, cold or at all times?

ciao

[MotoGuzzi750]

What model? Breva 750? Got a manual? 

https://guzzitek.org/gb/ma_us_uk/750/Breva750IE_042003_Atel(GB).pdf


Air filter & Throttle body cleaning are important, air screws also. Equally L & R at 1/2- 3/4 open. I do my EV every 10K mi

Sorry forgot to mention model: 2004, Breva 750 IE.

[MotoGuzzi750]

Here's a tip when looking for troubleshooting assistance. The symptoms are one thing but other salient information needs to be included some of which is listed below. Your issue could be many things but answers to the following will sure expedite the troubleshooting assistance.
Exactly which model and year bike are we talking about?

>>( Sorry forgot: its 2004, Breva 750 IE.

Is the bike ridden regularly?

>>Yes. I ride it most days for about 20 miles.

How many klms/miles on it?

>> About 20k Miles.

Has it just come out of storage or been parked for a significant length of time?

>> Not parked for more than few days. I ride it most days of the week.

Did you just refuel it before the issue?

>> Maybe. It could have started after I refilled last time, but I am not 100% sure.

Did you just recently wash it or ride it in a rain storm?

>> No.

Is it serviced regularly?

>> No. Did not have to. I changed engine oil, transmission oil, final drive oil myself. I don't have previous owners records.
I have owned it since it had about 18k miles, and now it has about 20k miles, so driven for about 2k miles since June 2021.

Has it just been serviced/worked on?

>> Yes, Have worked on fuel filter pump motor, which had fallen off the assembly into tank, I have tied motor to assembly using metal wire.
 
What was the very last thing done to the bike before the issue?

>> I had replaced a blown fuse, because the battery was not getting charged.

What weather conditions are we talking about and does it have the issue when the engine is hot, cold or at all times?

>> This happens both when engine is hot or cold. I drive it during daytime around 70 Deg F. Not rainy, Not windy.

Thanks.

ciao

[lucky phil]

Oh ok I remember this bike. Didn't we sort this? obviously not I guess.

Ciao

[MotoGuzzi750]

Oh ok I remember this bike. Didn't we sort this? obviously not I guess.

Ciao

Yes it’s that bike. It ran fine for few weeks and recently I started to run into low rpm problem again.

[fotoguzzi]

Have the valves ever been adjusted?

[Redrider]

M2c. Start with the charging system then fuel delivery.

[Rolf Halvorsen]

Yes, Have worked on fuel filter pump motor, which had fallen off the assembly into tank, I have tied motor to assembly using metal wire.

Your problem is probably low fuel pressure do to bad work on the fuel lines inside the tank.

Take it out again and replace the fuel lines with new - and use proper clamps.

[tris]

Dying Cam Sensor?

I seem to remember my B1100 doing something similar until I changed it

[guzzisteve]

Cleaning TB's, a TB sync & plug in to software for TPS setting really does wonders on how bike runs if not done recently.

Even taking out air screws and cleaning that passageway & screws off makes a difference. Then set them the same, a little more open will bring your idle speed up.

[MotoGuzzi750]

What model? Breva 750? Got a manual? 

https://guzzitek.org/gb/ma_us_uk/750/Breva750IE_042003_Atel(GB).pdf


Air filter & Throttle body cleaning are important, air screws also. Equally L & R at 1/2- 3/4 open. I do my EV every 10K mi

Thanks for the link to the manual. Appreciate it.

[MotoGuzzi750]

Have the valves ever been adjusted?

I don't know if previous owner did valve adjustment. And I have not done it since I owned it since last summer.