2004 M620
Last Desmo service, October 2015, performed by me, last oil/filter service, performed at dealer April 2016.
Customer states bikes idles very low after "fast idle" is disabled, engine idles at about but no more than 1000rpm+-50; while riding it, it will suddenly bog down when given gas.
Values measured with Socio and Centurion: TPS 2.7° Trim 18 Inj time 2.4ms air bleed screws, 2.5 turns out on both cylinders
OEM exhausts with cat wont heat up, after a while riding it or idling it, they are still just warm and was able to grab them without gloves, cat part was also just warm to touch; for some reason HEAVILY leaning towards the exhaust being "fubar" since, exhaust coming out is cold and if I place my hands on either exhaust engine will shut down.
Any ideas?
when you can grab those exhausts what is the engine temp?
Possibly a clogged cat?
seems odd that an oem exhaust would be that cool at running temps.
Is the bike fueling correctly?
why does it have 18 trim if all stock?
air fuel or CO?
it sounds like something is not right there I would look at the plugs
compression/leakdown
check CO at the ports
check air filter for mouse nest
Sorry, CO measured at the measuring ports in headers avg for both 3.4% front 3.4 rear 3.6 . . . airbox has resonator cut off . . .
In my bike with open top airbox and Termis I run 23 trim setting and CO avg was 3.8%, usually rear a bit richer than front . . . This is one of the few Monsters from Gen 1.5 that has OEM exhaust set up, plugs are nice, no leaks doesn't smell like gas when idling, just has a real low idle and will bog when under load
Sadly at home I don't have too much equipment, Gunson CO meter Socio/Centurion for diagnostics and no bike to compare since mine is just occupying space.
can you put your exhaust (cans)on his bike to test?
Did that, OEM cans, bike ran better and I got burned !!! Didn't know I had them laying around
Still idles a bit low with airbleeds at 2.5 turns out . . . gonna check tomorrow morning, when is NOT raining, and screw them to 3 turns out . . . Didn't bog as hard
Remove the mufflers and see what happens or go old school diagnostics. Hook up a vacuum gauge to one of the ports for throttle synch, or better yet, both with a tee. Note reading. Bring engine speed up to 3-4K RPM. Vacuum reading goes down, clogged exhaust.
Eric beat me to the exhaust.
Quote from: howie on July 06, 2016, 03:43:32 PM
Remove the mufflers and see what happens or go old school diagnostics. Hook up a vacuum gauge to one of the ports for throttle synch, or better yet, both with a tee. Note reading. Bring engine speed up to 3-4K RPM. Vacuum reading goes down, clogged exhaust.
Eric beat me to the exhaust.
Will do . . . now, where did the missus placed my vacuum meter?
Went OLD school, vaccumm for both intakes was about wvenat idle and 3500RPM . . took cans off, made lots of noise, bike didn't bog as hard . . . Re-installed my old OEM cans and from 1 to 10 it was an 7.5 . .
Would an expanded tank that builds up preasure be an issue?
As long as it is venting properly, no. Clogged cats make me wonder what your CO levels are, particularly at cruise.
Quote from: howie on July 11, 2016, 08:43:54 PM
As long as it is venting properly, no. Clogged cats make me wonder what your CO levels are, particularly at cruise.
Idle CO avg for both, 3.9% . . . at the rear, front cyl 3.8% vert cyl 3.9%, trim setting 18, any lower CO would drop avg of 0.4 . . .
After a while of riding or just sitting in my uncovered car port, bike wouldn't start unless I opened the tank cap and a BIG "POOOF" would come out and then bike would start normally . . .
Customer has bike now and states that after a while riding, it will bog but, NOT as hard as before . . . for some reason, I am leaning towards the tank internal venting . . .
POOF not good. Poof in or out?
Quote from: DarkMonster620 on July 12, 2016, 06:08:20 AM
Idle CO avg for both, 3.9% . . . at the rear, front cyl 3.8% vert cyl 3.9%, trim setting 18, any lower CO would drop avg of 0.4 . . .
After a while of riding or just sitting in my uncovered car port, bike wouldn't start unless I opened the tank cap and a BIG "POOOF" would come out and then bike would start normally . . .
Customer has bike now and states that after a while riding, it will bog but, NOT as hard as before . . . for some reason, I am leaning towards the tank internal venting . . .
It's not uncommon on steel FI tanks for the vent tube in side the tank to become clogged solid with rust.
They can be cleared, but it's a PITA.
Blow compressed air through the vent hose. That will tell you. That doesn't answer the low idle issue, or the bogging. Usually they just stop running.
Quote from: howie on July 12, 2016, 06:22:37 AM
POOF not good. Poof in or out?
OUT
Quote from: ducpainter on July 12, 2016, 06:32:22 AM
It's not uncommon on steel FI tanks for the vent tube in side the tank to become clogged solid with rust.
They can be cleared, but it's a PITA.
Blow compressed air through the vent hose. That will tell you. That doesn't answer the low idle issue, or the bogging. Usually they just stop running.
Sadly, plastic tank
Quote from: DarkMonster620 on July 12, 2016, 06:39:17 AM
OUTSadly, plastic tank
I see now way for that plastic internal tube to become clogged. Perhaps the screw in fitting might rust and clog.
The pressure vent is built into the cap. It's a little rubber diaphragm. Might be stuck. Pressure in the tank would not inhibit the flow of fuel.
Gonna get it back Saturday for a few hours . . . will take fuel cap off
Quote from: DarkMonster620 on July 12, 2016, 09:57:17 AM
Gonna get it back Saturday for a few hours . . . will take fuel cap off
Be very careful...all kinds of stuff will go flying if you take it apart. ;) ;)
Quote from: ducpainter on July 12, 2016, 10:07:30 AM
Be very careful...all kinds of stuff will go flying if you take it apart. ;) ;)
I know . . . I took mine apart once . . .
So, customer reported that bike is OK, not what I want to hear, but OK doesn't have him calling every day . .. Bike still bogs on hot days while riding in traffic . .. States than when he opens the fuel cap, BIG hiss comes out and bike doesn't bog if he rides with cap open but he can only do that with no more than 1/2 tank or it will spill . ..
Will soon install Marving Low Mount CF slip ons and will try to see how I can vent the tank to the outside . . . BUT first, I will try to see if breather is clogged . . . Need to find a 3mm[1/8"] stiff enough not bend/break inside the tank . . .
Will keep updates coming . . .
saw your thread in another about rough running.
my 04 620 idled really low (~800-900). I had to open the fast idle almost all the way to get it to idle at 1000-1200 until it warmed up. And that was in the middle of summer, 70-degree 6am starts. I replaced the relays near the battery (left side under tank) while chasing a weird electrical fault.
http://www.ducatimonsterforum.org/index.php?topic=73631.0 (http://www.ducatimonsterforum.org/index.php?topic=73631.0)
replaced them and it idles ~1000-1100 with no fast idle applied.
not sure if that'll help, but it's a cheap/easy fix.
Quote from: Privateer on September 14, 2016, 05:15:39 PM
saw your thread in another about rough running.
my 04 620 idled really low (~800-900). I had to open the fast idle almost all the way to get it to idle at 1000-1200 until it warmed up. And that was in the middle of summer, 70-degree 6am starts. I replaced the relays near the battery (left side under tank) while chasing a weird electrical fault.
http://www.ducatimonsterforum.org/index.php?topic=73631.0 (http://www.ducatimonsterforum.org/index.php?topic=73631.0)
replaced them and it idles ~1000-1100 with no fast idle applied.
not sure if that'll help, but it's a cheap/easy fix.
Thanks . . once I get the bike back to install Marving Exhaust I will replace the relays and check . . .