The most "worth it" upgrades - Breva 750

[willard]

38mpg is low. There's something not right. 45-55 is the usual range, and I think it's unlikely to ever get much better than 55mpg.. Sustained high speed riding (80-85 mph - trying to keep up with big blocks) might bring it closer to 45.

It could be a lot of things, or a combination. So start at the beginning - a full service (oils, filters, tappets, plugs), check tyre pressures, check for the brakes dragging, wheel bearings, that sort of thing. If the air filter & airbox was too filthy, it would be running roughly & perhaps missing at around 4,000rpm.& you'd know about it. Try re-setting the ECU after your service - remove the negative terminal on the battery for a few minutes, then ride for, say, 50 miles. Check the plugs - are they soothed up already? Does the motor idle at 1100 +/- 100rpm? Check that both overflows in the tank are unobstructed.(the tank will have to come off for that I'm afraid). While you are there, drain the fuel & check for water in it., replace with fresh stuff. While the tank is off & empty, I would take out the fuel pump to check the state of the filter & the hoses in there.

When the basics have been covered, see if you can find someone who has Guzzidiag & the cables to check the map you are running & to find out if there are any errors stored. At 30,000 miles the motor is still relatively new & it shouldn't have been molested with too badly. Let us know how you go.

Thank you. I already have the oil change kit, valve cover gaskets, and air filter ordered from MG Cycles, so I should be able to do the service before very long.

I've been running no ethanol fuel for the past 100 miles, at least, so I'm pretty sure there's no water in the tank. I'll order a new filter and change it out, regardless.

The bike seems to run well, aside from the popping on deceleration. It's been a pleasure thus far. I've been thinking about going to the North Georgia/Tennessee Guzzi meet up on the 18th, so maybe someone there will be able to check my ECU. 

[Muzz]

I will be dealing in imp. gallons.

I get about 270 miles out of a tank (that hasn't run out but rattling). Close to 70 mpg(imp) Cruising at highway speeds a bit over 65mph.

On the Tattley Rappet I was cruising at 6200 in top for quite a while, dropped to about 61mpg.

No burps, farts or missing.

[malik]

On ya Muzz. Good to have a proper target in proper gallons.

6200rpm. I take it you were chasing (or leading) the odd V11 & other assorted big blocks, or perhaps Neill's 1000S - locals on their own roads).

Came across a couple of Breva's for sale at a dealer in Hastings earlier this week. Tempting.

[malik]

The Breva popping on decel? Check first for air leaks in the exhaust system. Perhaps try replacing the exhaust gaskets - they don't last forever. Note that the exhaust nuts have a tendency to seize on the studs over time. An occasional loosening & re-tightening helps prevent that.

[willard]

The Breva popping on decel? Check first for air leaks in the exhaust system. Perhaps try replacing the exhaust gaskets - they don't last forever. Note that the exhaust nuts have a tendency to seize on the studs over time. An occasional loosening & re-tightening helps prevent that.

I'll check that out.

Just filled the tires today. I'm running Avon Roadriders, and 42 psi was what was posted on both tires. This seems a bit high, but the tires were around 30 psi rear and 25-30 front, so I knew they were low. I filled them up to 40 psi each. Handling seems improved. I also installed a new air filter today. Not as easy as my old Honda's for sure, but I got it done in 30 min or so without removing the tank. Power seems better in the low and mid rpm bands, but I'm unsure if this is real or placebo.

I found something I thought met my standards of "worth it". Joe kenny head guards, as posted in another thread here. I'm waiting to do my valves so that I can install the head guards at the same time.

Also, I bought some cheap adjustable levers from ebay.

[malik]

The 42 psi on the tyres is, I think, the theoretical maximum. (Check on the Avon website or other tyre nomenclature demystefiers on the web). The original Breva manuals call for 31 & 35. But then the V7 manuals (a different size tyre) started out saying 32 & 36, then later changed to 36 & 36.  I run the Roadriders on my V7's at 36 & 36 and get decent mileage out of them.

Yes, a clean air filter can make a difference. You'll get faster than 30 minutes with practice. I have done it removing one horn only, but usually both & sometimes even the reg/rec for additional room. It's the juggling of that lid that seems to take the time.

[M0T0Geezer]

My Breva pops mildly on decel using E10 93 octane gas and E0 87 octane gas. So I'm assuming the ECU may have already been flashed to run more rich. Or is that a misled assumption?

Edit: I just filled up and got 38mpg doing light commuting. 65 percent 45-50mph backroads and 35 percent highway 75mph. This seems a little low. Ideally I'd be 45-55 mpg with 55-65mpg with full highway miles. Is this possible with the breva 750? If so, could my low mpg be linked to my, assumedly, rich fuel condition?

I just aquired this bike a week ago with 30,000 miles, so I have no idea what's been done to it, but it seems completely stock to me.

"Popping, backfire, after-fire" by whatever name, means that enough fuel and air - and in the right ratio -  is present in the exhaust stream to be lit off [usually] by latent heat in the pipe.  Too-high octane (that's right, see more further below) and/or too tight (or no) exhaust tappet clearance (causes premature valve opening and burning) can put raw flame into the exhaust stream, providing an ignition source for popping.  Buy two new valve cover gaskets and check clearances on all four valves asap.

VALVE CLEARANCE  Guzzi Breva 750cc     
   0.006 inch (0.15 mm) intake
   0.008 inch (0.20 mm) exhaust

The TPS (Throttle Position Sensor) should be checked and set by your dealer.  That will be helpful in making sure no excessive fuel is being injected on deceleration (Closed Throttle).  Also be sure all exhaust joints are tight and all have their factory gaskets (a 30,000 mile bike is probably missing some). Any excess fuel and/or source of outside air will also cause popping. 

38 mpg is way too low.  Have you checked that your disc brakes are not dragging (especially the rear one)? As pads wear down, ever more caliper piston is being permanently exposed to road elements.  Corrosion on the exposed piston will cause failure to fully retract, causing drag. Just a little brake drag can cost you much mpg (and lower performance).  Be sure to service (disassemble, inspect, clean) the brake caliper next time you take off the wheels.

Factory ECU settings are more likely to be too lean (blame: lawyers & eviro laws) than too rich. If TPS is right, the air cleaner is actually clean (replace to be sure), and injectors are working properly, then 38 mpg is too low.  How do your plug colors look (should be light tan inside)?  Has the PO (Previous Owner) jacked around with the O2 sensor or added any kind of Power Commander etc?

My '04 Breva came from the PO with an after market Power Commander and other add-on electronics.  Engine ran nasty/evil, hard starting, surging, with lots of popping and only 38 mpg.  Plug color was coal black.  I took all this off and had the ECU reflashed by Todd over at GuzziTech.  Best $250 I ever spent.  Now my Breva is sweet running and gets high 50s for mpg - definitely now an ally, not an adversary.  Plugs are now running light tan & popping is minimal (I have leaky, rusting out exhaust).

FLAME ALERT: Below I now open myself to Cruel Fuel Flaming & Shaming.

The higher the octane, the slower burns the fuel. That's what keeps a high-compression engine from detonating ("knocking").  The higher the compression, the more likely is the engine to detonate (similar to "dieseling").

The Breva 750 is not a high compression engine (about 9:1).  Where I live at 5,000 ft altitude, working engine compression is much lower than at sea level.  Therefore I use only lowest octane (85) pump gas. It's all she needs.  Never knocks, not even one 115 degree afternoon 18 months ago in Moab, Utah.

Further, I declare that using needlessly high (or highest 92) octane can actually reduce miles per gallon if the exhaust valve opens before a high octane fuel charge has had a chance to fully burn.  If raw flame gets into the exhaust stream then popping can result.

Now that I have lost all credibility with some, I retreat to eat my dinner...

'Geezer

[Muzz]

I am basically at sea level here Geezer and although mine will run on 91 it pinks like crazy at the first rise it comes to unless I don't go any lower than 4 grand. Sweet as on 95. Gave it a good go on 91 but we just have too many hills for it to be good for the motor. 95 only now.

[Muzz]

6200rpm. I take it you were chasing (or leading) the odd V11 & other assorted big blocks, or perhaps Neill's 1000S - locals on their own roads).

I got passed by Neil (nice bike that ) at about the half way point to Kaikoura. I was sort of in the leading lot rather than trailing, but wasn't actually chasing anyone. On the way back I was following Cod's 1400 (he had a scanner fitted). Good thing too!

[willard]

"Popping, backfire, after-fire" by whatever name, means that enough fuel and air - and in the right ratio -  is present in the exhaust stream to be lit off [usually] by latent heat in the pipe.  Too-high octane (that's right, see more further below) and/or too tight (or no) exhaust tappet clearance (causes premature valve opening and burning) can put raw flame into the exhaust stream, providing an ignition source for popping.  Buy two new valve cover gaskets and check clearances on all four valves asap.

VALVE CLEARANCE  Guzzi Breva 750cc     
   0.006 inch (0.15 mm) intake
   0.008 inch (0.20 mm) exhaust

The TPS (Throttle Position Sensor) should be checked and set by your dealer.  That will be helpful in making sure no excessive fuel is being injected on deceleration (Closed Throttle).  Also be sure all exhaust joints are tight and all have their factory gaskets (a 30,000 mile bike is probably missing some). Any excess fuel and/or source of outside air will also cause popping. 

38 mpg is way too low.  Have you checked that your disc brakes are not dragging (especially the rear one)? As pads wear down, ever more caliper piston is being permanently exposed to road elements.  Corrosion on the exposed piston will cause failure to fully retract, causing drag. Just a little brake drag can cost you much mpg (and lower performance).  Be sure to service (disassemble, inspect, clean) the brake caliper next time you take off the wheels.

Factory ECU settings are more likely to be too lean (blame: lawyers & eviro laws) than too rich. If TPS is right, the air cleaner is actually clean (replace to be sure), and injectors are working properly, then 38 mpg is too low.  How do your plug colors look (should be light tan inside)?  Has the PO (Previous Owner) jacked around with the O2 sensor or added any kind of Power Commander etc?

My '04 Breva came from the PO with an after market Power Commander and other add-on electronics.  Engine ran nasty/evil, hard starting, surging, with lots of popping and only 38 mpg.  Plug color was coal black.  I took all this off and had the ECU reflashed by Todd over at GuzziTech.  Best $250 I ever spent.  Now my Breva is sweet running and gets high 50s for mpg - definitely now an ally, not an adversary.  Plugs are now running light tan & popping is minimal (I have leaky, rusting out exhaust).

FLAME ALERT: Below I now open myself to Cruel Fuel Flaming & Shaming.

The higher the octane, the slower burns the fuel. That's what keeps a high-compression engine from detonating ("knocking").  The higher the compression, the more likely is the engine to detonate (similar to "dieseling").

The Breva 750 is not a high compression engine (about 9:1).  Where I live at 5,000 ft altitude, working engine compression is much lower than at sea level.  Therefore I use only lowest octane (85) pump gas. It's all she needs.  Never knocks, not even one 115 degree afternoon 18 months ago in Moab, Utah.

Further, I declare that using needlessly high (or highest 92) octane can actually reduce miles per gallon if the exhaust valve opens before a high octane fuel charge has had a chance to fully burn.  If raw flame gets into the exhaust stream then popping can result.

Now that I have lost all credibility with some, I retreat to eat my dinner...

'Geezer

Geezer, thanks for your generous response. Have taken your advice and will be adjusting the valves tomorrow. I left the Breva at home today anyway, since it is supposed to rain.

I doubt brakes are dragging, but I was very very low on fluid in the rear reservoir. This seems to mean the rear pads have been worn considerably. I will order new pads with the fuel filter.

Anyone know any places that regularly stock 10w-60 oil for my upcoming oil change?

[sign216]

Anyone know any places that regularly stock 10w-60 oil for my upcoming oil change?

You can get 10w-60 at a BMW car dealer, they used to use it in an old model.  My local BMW auto place had Castrol 10w-60 cheaply, but they've since changed to BMW-branded oil and upped the price.  Ain't progress grand?

[Arizona Wayne]

I am basically at sea level here Geezer and although mine will run on 91 it pinks like crazy at the first rise it comes to unless I don't go any lower than 4 grand. Sweet as on 95. Gave it a good go on 91 but we just have too many hills for it to be good for the motor. 95 only now.

I run my `04 750 Breva on 87 gas all the time @ any altitude and get no pinging even when riding 2up & loaded.  Our ignitions are supposed to automatically adjust for altitude changes and my spark plugs always look spot on.  I get 50 mpg.   Bought my bike used and have never touched the timing.   Changed he mufflers on it and the bike seemed to adjust to that on its own.   

I run 38 # front tire, 40# rear tire for no front tire cupping and longer tire wear and no bent rims if I hit  an unexpected hole.  I don't mind a firm ride and don't have to adjust my tire pressure when carrying more weight, which then makes the ride a little softer.

[Muzz]

What tires are you running Wayne? Any thoughts on them?

[willard]

Picking up some 15w-50 oil since that seems to be more common and is the recommended alternative for the 10w-60.

[Sheepdog]

I run my `04 750 Breva on 87 gas all the time @ any altitude and get no pinging even when riding 2up & loaded.  Our ignitions are supposed to automatically adjust for altitude changes and my spark plugs always look spot on.  I get 50 mpg.   Bought my bike used and have never touched the timing.   Changed he mufflers on it and the bike seemed to adjust to that on its own.   

We measure octane a little different in the US. Our numbers are lower because the RON and MON techniques are averaged. Here regular unleaded is typically 87-88 R+M and premium unleaded is 91-92...

[malik]

Picking up some 15w-50 oil since that seems to be more common and is the recommended alternative for the 10w-60.

No worries. I've been running the V7C (same motor) on 15w50 (Penrite later changed it to 15w60) for 7 years & 170,000km. Mind you, the motor has never been apart, & no forensic examination been done, but it's still running well. As long as it's running well, I'm not going to "fix" it.

[malik]

I run both the V7s on 91 & 95, and I haven't noticed/ am not aware of any significant difference in either running or consumption. I keep records, and one day I may get around to reading my old statistics texts & running the data through some rigorous mathematical models, just for fun. But I suspect the Difference will not be significant, especially as the measurements are imprecise - different gauges on different bowsers & every ride being different.

I've run 98 a few times, and 100 twice, and have not noticed any difference, other than the Shell 98 which may have resulted in starting problems on the V7C when relatively new. The additives in Shell 98 have been said to be inappropriate for our engines.

Stick with the lowest rated, or the next lowest, non-ethanol fuel & you should be OK. If you experience pinging as Muzz does, go the next one up. Easier for us - it appears to be harder for you guys in the US to avoid ethanol.

[willard]

So I did the service yesterday but it wasn't all perfect.

I couldn't get the front oil drain bolt off, so I decided to just leave it on. Then I added the oil. Once I did that I realized that I didn't change the filter. I'll be changing my oil again relatively soon. Maybe 2000 miles.

I did adjust the valves and add the head guards on. That was the easy part. Valves we're pretty in spec, although I did adjust the left side, just to be sure.

Spark plugs looked like this:



I also changed the transmission/5 speed box oil. That was pretty easy too. Didn't even have to rotate the crossover.

Now, while I was doing all that, I noticed a hole in my left side exhaust silencer. Then I noticed there was a similar hole in the right one. Pretty sure the PO wanted a louder sound, so he hacked them open. Maybe this is linked to my low MPG and popping on decel?



Then I noticed the left side exhaust silencer was barely held on by this little hose clamp.



It wiggles when I push it around.