Engine Ping and Stumble

[Guest Scura Owner]

Does anyone else experience engine pinging? And what can be done for it? I have been getting pinging at full throttle from 3500 to 7000 rpm. I use prem. gas. The CO reading are 4.5% at idle.

 

I also get a stumble around 2000 rpm. When pulling away from a stop, I occasionally get a mis-fire/stumble. It makes you look like you do not know how the drive a manual transmission. And I get a miss at idle. It will be ticking away at 1000 rpm and then a miss, droping the rpm to 650. And back to 1000 rpm.

 

All this symptoms seem to get worse at hotter the ambient temperature. My mechanic says there is nothing he can do as timing is fixed and the CO readings are within spec.

 

Any ideas?

[al_roethlisberger]

...no, this isn't normal.

 

Did this just start? My LeMans has "missed" 4 or 5 times since I've owned it, but it was a quick lone-event... and I've never had a prolonged stumble or pinging. I also use "premium" fuel.

 

I don't know the solution, but I'd have your map checked as well as the stadard tune-up stuff. If your shop can't find anything, try someone else. Also, we saw that one fella apparently had a bad computer that was making diagnosing his similar problems very difficult. You could check into that as well.

 

BTW, I actually got 36 1/2MPG the other day.. whoo hoo.. ah hem

 

al

[Guest jimjib]

Yes, i have a sucra too and it does ping when you really get on it, on a hot day. I am thinking I may need to fatten the map up a bit with the pc

[Guest Scura Owner]

My dealer does not seem to want to change out parts unless it is proven to be a problem. I have been tolded by the mechanic that the computer does not save error codes when the key is turned off. So no error code no problem. Of course it idles perfect nor does it stumble for him. Cooler in the shop?

 

Al - Gas mileage has been another issue. At first it was in the low low 30's. At 3000 miles, it had improved to 45. My best was 46.6 mpg. It went 188 miles before the light started to flicker. I went 220 miles and put in 4.72 gallons. I just readjusted the valves and my mileage seems to have dropped to 44. It could be weather (slightly cooler now) or the valve adjustment.

[Guest JohnInNH]

45MPG!!! WOW.... What I'd do for 45 mpg... Best yet is 40 for me. I get 35 -38 with 37 as the norm. The CO at the 4.5% may be the problem, and it's running on the lean side. My guess would be have em set the bike up with CO at no LESS then 5%.

 

Where did I read it, but maybe the MGCL, had a post about CO #'s and bike performance/mileage. I have been reading so much on the V-11/LeMans I really don't remember.

 

My $.02

[Guest marcialc]

hey unknown scura owner...did u do a hard break-in or easy break-in? wondering if it may have an effect on the MPG results.

 

BTW I'm getting low 30's with about 800 miles on so far, hard break-in...

[John O'Sullivan]

Hello fellow Scura owner,

 

As this bike is new, I would politely request satisfaction from my dealer and failing that I would suggest that you contact your Moto Guzzi Importer with a Letter (keep a copy) as this provides proof if the matter requires legal action.

 

This problem of yours may require a TPS check and some other minor wrenching.

 

Best of look,

 

John

 

02 Scura with 2,500 happy km.

[Guest Scura Owner]

I adjusted the TPS. It was reading a little high at 180 mv. I adjusted it to 170 mv. I was being careful since this should lean it out further. At 170 mv I will get approximately 150 mv if I put pressure on the TB with my thumb in the closed direction. The proper CO reading per the V11 service manual is 3 to 3.5%. So it is still running slightly rich at 4.2%. It was originally running at over 6% when I took it in for the first service.

 

I had the stumble since new.

 

I also had "beyond" vapor lock experience where all the symptoms of vapor lock occurred while the engine was running. I got of the highway into stop-and-go traffic. The engine start running rough. I pulled to the side of the road. The engine started to run on one cylinder then died. The engine would start but would only run for about 20 to 30 seconds then die. This went on for about 10 minutes. I started to pull the plugs only to find that the plug wrench did not fit the plugs (check yours for your own amusement). I attempted to remove the tank only to find out that there is no wrench in the tool kit. I unplugged and replugged all the connections I could find. After being stranded for a hour and half and having made arrangments to have the bike picked up, the bike started and ran like there was never a problem. My dealer attributed this to the relays. Remember mine is a 2002 with the new and improved relays.

[John O'Sullivan]

Scura Owner,

 

When I checked my '02 Scura relays, I found two (2) of the old bad Siemens relays and have replaced all with Tyco relays which were sourced locally.

 

Regards,

 

John

[Guest jimjib]

I found this little tidbit on a gs board.....

 

My bike used to do the pinging thing often under heavy loads (acceleration in third gear out of a turn). Your riding two-up so that's qualifies as a heavy load. You may not rev as high when she's on board, making an even heavier engine load. Carbon seems to build-up in a hurry if the engine is lugged. It sounds like your running the revs a little low.

 

What I've done to resolve the problem is ride harder and use Techtron occasionally if it seems bad. Riding harder, means keep the revs high (cruising above 4k and downshift often). After a hard days ride the pinging is always gone. If I comute too many days without enough revs, the problem returns gradually. Techtron breaks down the carbon. I use a whole bottle in a fresh tank and then ride at high revs for the tankfull to clean it all out. Seems to work well for about 3000 miles, then I do it again.

[jtucker]

I've got about 16,000 miles on my V11S and it has always had a pinging problem under heavy acceleration in higher gears. TPS and what-not is set up OK. Someone recently suggested to me that I try replacing the stock coils/wires with better aftermarket items. I haven't had a chance to try this yet. If that doesn't solve my problem, I'm going to consider dual-plugging the heads this winter...

 

__Jason

00 M900Dark

00 V11 Sport

[Guest jimjib]

Several guys on the gs board are now saying a step colder plug totally cured their pinging problems. Thats an easy one to try.

[Guest v11eric]

I think you all drive to few rev's. On normal driving I always drive 5K, when there is a twisted road my reve's lay between 5.5 and 7k. This is where max torque is available and the engine runs most "efficient".

Driving 3K in third gear opening the trottle is asking for pinging

 

over 5000

 

eric 01 V11 lemans

[Guest Jaap]

That I can relate to! Keep up the revs!!!

[Guest Guest]

I can't speak for the rest, but I can assure you that I do keep the revs up on my bike. Typically cruise around 5.5-6K RPM. However, if I'm cruising along at say... 5.5 RPM and whack the throttle wide open (as if to pass a car) and it pings big time.

 

I had a header clamp come loose on me once, so I check those nuts periodically for tightness. TPS/mixture gets checked every once in a while by my mechanic. No problem there. It just pings.

 

Popular opinion on the MGCL is that it has something to do with combustion chamber shape of the newer V11 motors. If I ever figure it out for myself, I'll be sure to let folks know. It seems to me that this problem has affected quite a few people.

 

__Jason

00 M900Dark

00 V11 Sport