Breva 750E (2007) engine noises

[jest2dogs]

Well, at the behest of the MI service manager I am checking out the tappets for possible loose fitments that may be causing a "rattle" emanating from the heads (?) between 2,900-3,200 rpm. It's not that nice "clickety" of properly adjusted valves (that is also audible)but a real metallic rattle.

Along with that has been some erratic starting, especially after being out in the evening dew and a surging while running down the road.

So, at the first step of tappet expose' I pull the plugs to find nearly white electrodes. Not the nice chocolate brown seen an hour earlier on my other machine (2006 Royal Enfield). There's a tinge of brown at the bend of the side electrode but the flat is about the color of my 58 year old sideburns. Checking the plug gap with the only gapper I have shows a good .64mm gap on the BR8ES at 1,400 miles.

I am still pulling the tappet covers off. The right side showed beautiful adjustment from the shop at the 600 mile check (now at 1,400 miles.) I will let you know if I find anything awry in the the left side.

But the surging and the color of the pugs and the hard starting The other night after it sat out in the night air for about 4 hrs it was covered in dew. I gave it a little enricher and fired it up. It was like it wasn't the same bike, it missed it, rocked it, it ran on one cylinder then it stalled. I had to play with the throttle to get it to finally stay running and over the next four miles it was surging while holding a steady throttle at about 2,800-2,900 rpm on level ground. On the 5th mile just before home I rolled on the throttle for a long uphill sweeper (60mph/4,000rpm) to see if she would clean out the gunk. But even then I felt her miss a few beats.

Two days ago I went on a 38 mile ride and I put the 33nrr earplugs in and just went riding. It was a dry day and I didn't notice anything. (Earplugs are nice sometimes.)

Could the EFI be getting moisture on dewey nights. What gonna happen if I have to ride in the rain?

And she doesn't seem to idle evenly, kinda lumpy. I would expect more from EFI but then I am new to it. I've had three Beemers (/5 & /6) and a 1980 V50 so I am no newbie to balancing carbs, but EFI I know nothing about.

What publication/tools do I need to get so I can stop driving Micha crazy? :lol:

OR? Is all this normal for the smallblock, and I just have to get used to it? (BTW, I am not getting more than 45 mpg yet thoufg most of my riding is rural.)

-Jesse in P.A.,WA

 

[john zibell]

Start by reading this thread.

https://www.guzzitech.com/index.php?op ... id=44#6819

The instructions are for the 1100 Breva, but the procedure is the same for the 750. If using VDSTS on the 750, the channel to monitor for the TPS reading is ALFALIN_0. Be sure to not touch the stop screw on the left TB. All high rpm adjustment is with the left to right sync screw on the linkage and idle with the air bypass screws, only on the 750, both air bypass screws need to be open about 1/2 turn or so. A one ECU only version can be purchased for a reasonable price. Contact Todd @ GuzziTech.com Your 750 Breva uses the 15RC ECU.

For moisture, be sure your connectors are clean and coat with dielectric grease. Also use thermal mastic under the engine temperature sensor located in the right cylinder, you will get more accurate readings. In addition, white plugs are normal on a FI bike. They are set up to run pretty lean for emission reasons.

I'm not sure this will help with you noises as from your description it sounds more mechanical than a tuning issue.

Good luck.

 

[nutman]

If the noise your talking about is at that low rpm I would think more of pre ingition then mechanical. If the engine running at a higher idle you may have a vacum line loose. Make sure you use the best fuel you can get. I run my in the rain all winter and never had a problem. The plugs will be cleaner on an ECM motor because they do run leaner so as not to over heat the cat in the muffler. As long as the plugs are not missing any pieces and they don't have extra parts stuck to them I would really look at your fuel frist
lance

 

[jest2dogs]

John & Lance,

Thanks for your input.

John I read the thread and I guess if I'm going to do my own maintenance I'll have to step up to the plate on this computer stuff. Thanks for the link and the 750 specific information.

Lance, I use the highest grade gasoline available to me. I sure hope it isn't pinging. It seems to lessen when warmed up (or maybe by then I am used to the sound? :O)

BTW the left side tappets were as acurrately set as the right...spot on, and nothing loose.

Thanks again for your responses.

-Jesse

 

[Holt]

I've found the Breva to run somehow, actually very, different depending on weather and temperatur. Can be quite rough when cold and humid; spinning like a cat under other circumstances.
Seems to preffer heat & sunshine, but as I do the same, that's certainly no problem. :laugh:

Only thing coming to my mind besides what's said, would be checking the plug cords and the coils. The later shouldn't be affected by moist when standing for a few hours, though. You're describing what to me would be tick-overs? It's a long and cheap shot, but could it be a cracked plug cable or another pinched cable somewhere?
Living in a humid country I usually treat all cables, cords and connections with silicone oil to keep moisture out, twice a year, just to keep the system in good and happy condition.

 

[draidt]

john zibell wrote:

Start by reading this thread.

https://www.guzzitech.com/index.php?op ... id=44#6819

The instructions are for the 1100 Breva, but the procedure is the same for the 750. If using VDSTS on the 750, the channel to monitor for the TPS reading is ALFALIN_0. Be sure to not touch the stop screw on the left TB. All high rpm adjustment is with the left to right sync screw on the linkage and idle with the air bypass screws, only on the 750, both air bypass screws need to be open about 1/2 turn or so. A one ECU only version can be purchased for a reasonable price. Contact Todd@guzztech.com Your 750 Breva uses the 15RC ECU.

For moisture, be sure your connectors are clean and coat with dielectric grease. Also use thermal mastic under the engine temperature sensor located in the right cylinder, you will get more accurate readings. In addition, white plugs are normal on a FI bike. They are set up to run pretty lean for emission reasons.

I'm not sure this will help with you noises as from your description it sounds more mechanical than a tuning issue.

Good luck.

John can you expound on this statement on monitoring the TPS on channel ALFALIN_0 for the 750, what screen is this done on. I can't get a PASS indication when resetting the TPS, it will step down to 0 then I get the error message " ECU is not responding". Can you help ? The bike runs fine and the idle TPS is at 3.2

 

[john zibell]

Daniel,

Marelli uses the name Alfaline_0 for the TPS. Go to "Channels" from the dashboard screen to select that for one of the parameters you are reading. It does sound like you are having a communication error between your software, the ECU, and the TPS. Try going from connected (engine not running) in dashboard mode directly to the active settings to try the reset. If that doesn't work, you may need to take it to someone (dealer) who can sort out the issue.

When the communications is working correctly, you can reset the Alfaline_0 setting (I believe it is 4.1 +/- 0.3), but the "TPS" value displayed at closed throttle never changes.