jest2dogs
Just got it firing!
- Joined
- Nov 19, 2008
- Messages
- 23
I really should be working on that our bathroom remodel project but here I am. What would make me think that talking about motorcycles would be more enjoyable than sanding, sawing, painting and plumbing? Hmmm :O)
Recently had the 6,000 mile service done on the Breva (at 6,700 mi). The TB's were out of sync. I saw the mech balancing them with the mercury vacuum tubes. What makes them go out of sync? I can understand carburetors with all their machanical parts wearing differently but an EFI controlled TB? (I recall my Beemer days balancing Bings with individual choke and throttle cables, diaphragms, etc. After it was gone it drove me to buy a Royal Enfield for, if not less maintenanace, at least simpler maintenance. (Ha Ha)
Later, after I found my wife enjoying riding pillion, in need of more touring room and power... Well, I was drawn to the Breva on the first test ride. I actually drove it home that day. EFI, I thought, was the cure for multiple carburetor issues.
Micha, at MI, explained that some less than smooth running was expected at some lower rpm levels due to EPA tuning restrictions. Or, as I call it "Teaching to the test". A poor way to teach and a poor excuse for making an engine run badly.
So, after the 6,000 mile service she seemed to run better, warmed up sooner f'sure. There was still that 2,500 and 3,000 rpm leanness around town. And, cresting 4,000 rpm, a little vibration/roughness which I remember when I was breaking it in.
But now I get another phenomenom. I'll start her, let her warm up enough not to stumble off the blocks (less time needed now than before, as noted) and bimble 4-5 miles through town to the open road. I'll go at least 15-20 miles at 4,000+ rpm/ 60+mph and then back into town. Now, back in town, she runs like crap. Though the tach needle will show an even 3,500 or 3,700, if she is below 4,000 she seems to hunt and surge like she does at the EPA mandated test levels. As I mentioned to Micha, the runners are equally pacing each other but they are puking.
At a time when folks can read the logo on the tank she is running poorly. Bad advertising!
It has been indicated to me that, due to liability I assume, the dealer cannot suggest or install non-standard mapping. I may have asked this before, but is there a map that allows this great little engine to run as it should? Do the European versions have this quirk? I know this site has a map available, but is there a stock map (like the V7C version) that solves these issues or ???
I imagine, because I do not really understand EFI or what mapping actually is, or how it's accomplished, that after a highway run at 4,000 + rpm and upon suddenly comng into town, it must be like a sprinter suddenly forced to walk and take shallow breaths rather than panting to keep up with his heartrate. Forced by a strangling map/EPA guideline and not helped instead, by a rich midrange circuit that would help cool off a hot engine.
Is that why these small blocks run so hot? Is the the EPA mapping forcing them to run leaner than engine parameters demand?
I hear some complaining about overun or deceleration "popping"after installing some new maps. What's with this?
I think this is a sweet little bike. I love the way it handles. I did not expect to like it as much as I do (I was looking to buy a V7C at the time). But what can be done to help it run more smoothly?
Not that I am into a "cruising" image, but it sure is embarrassing to ride through town with a strangled, or rather, underfed, engine that feels like it's stumbling under your seat.
And yet, I am told, that mine is one of the best running Breva 750's they've seen (at MI).
To me, "this" is a smooth running MG:
http://www.youtube.com/watch?v=Chd2rdej ... re=related
Comments, please.
Recently had the 6,000 mile service done on the Breva (at 6,700 mi). The TB's were out of sync. I saw the mech balancing them with the mercury vacuum tubes. What makes them go out of sync? I can understand carburetors with all their machanical parts wearing differently but an EFI controlled TB? (I recall my Beemer days balancing Bings with individual choke and throttle cables, diaphragms, etc. After it was gone it drove me to buy a Royal Enfield for, if not less maintenanace, at least simpler maintenance. (Ha Ha)
Later, after I found my wife enjoying riding pillion, in need of more touring room and power... Well, I was drawn to the Breva on the first test ride. I actually drove it home that day. EFI, I thought, was the cure for multiple carburetor issues.
Micha, at MI, explained that some less than smooth running was expected at some lower rpm levels due to EPA tuning restrictions. Or, as I call it "Teaching to the test". A poor way to teach and a poor excuse for making an engine run badly.
So, after the 6,000 mile service she seemed to run better, warmed up sooner f'sure. There was still that 2,500 and 3,000 rpm leanness around town. And, cresting 4,000 rpm, a little vibration/roughness which I remember when I was breaking it in.
But now I get another phenomenom. I'll start her, let her warm up enough not to stumble off the blocks (less time needed now than before, as noted) and bimble 4-5 miles through town to the open road. I'll go at least 15-20 miles at 4,000+ rpm/ 60+mph and then back into town. Now, back in town, she runs like crap. Though the tach needle will show an even 3,500 or 3,700, if she is below 4,000 she seems to hunt and surge like she does at the EPA mandated test levels. As I mentioned to Micha, the runners are equally pacing each other but they are puking.
At a time when folks can read the logo on the tank she is running poorly. Bad advertising!
It has been indicated to me that, due to liability I assume, the dealer cannot suggest or install non-standard mapping. I may have asked this before, but is there a map that allows this great little engine to run as it should? Do the European versions have this quirk? I know this site has a map available, but is there a stock map (like the V7C version) that solves these issues or ???
I imagine, because I do not really understand EFI or what mapping actually is, or how it's accomplished, that after a highway run at 4,000 + rpm and upon suddenly comng into town, it must be like a sprinter suddenly forced to walk and take shallow breaths rather than panting to keep up with his heartrate. Forced by a strangling map/EPA guideline and not helped instead, by a rich midrange circuit that would help cool off a hot engine.
Is that why these small blocks run so hot? Is the the EPA mapping forcing them to run leaner than engine parameters demand?
I hear some complaining about overun or deceleration "popping"after installing some new maps. What's with this?
I think this is a sweet little bike. I love the way it handles. I did not expect to like it as much as I do (I was looking to buy a V7C at the time). But what can be done to help it run more smoothly?
Not that I am into a "cruising" image, but it sure is embarrassing to ride through town with a strangled, or rather, underfed, engine that feels like it's stumbling under your seat.
And yet, I am told, that mine is one of the best running Breva 750's they've seen (at MI).
To me, "this" is a smooth running MG:
http://www.youtube.com/watch?v=Chd2rdej ... re=related
Comments, please.
He explained that the factory EFI system on these small blocks is quite rudimentary and that explains a lot. Of course it would be the aftermarket gurus who would find the solutions! 
