My stone when new with a tight motor would easily top 120 two up with luggage, that was ten years ago. Since then I have serviced it on the button, recently had the injection set at streffords, however, I seem to have lost a little urge.I removed the balance box about three years ago, just have two pipes in its place so the system is now unbalanced, there is no lambda sensor on my bike, its a 2003, but built 2001 I think. Filters replaced at 10k, valve clearances done then also, shes just approaching 16k.It will just about crack the ton in fourth but into fifth and she loses a little steam.Any ideas??
when did you last check or change the air filter was that done at 10000 as well could be getting blocked.
The performance Im now getting is solo with NO luggage.
What he said , By the way the bike may run ok without a balance pipe BUT they are there for a reason. In a couple of the “Guzzi” books and Guzziology there is a fairly well written piece re balance pipe, what it does and why it is there.
Nothing to do with current problem by the way. most likely air filter or sticking choke.
Didnt think the choke was anything more than a fast idle on these injection bikes?
You’re rightSilly question but could it be increased resistance? Thinking brakes, bearings etc.Steve
10 years is quite a while,not pie related is it Sorry
Pretty sure I may have gained half a stone perhaps, the pre sluggish speeds were two up WITH loaded hard luggage.
Can’t fault check the air filter. Have you checked the compression? Most mechanics will go it for you FOC
“Valvish” was my first thought too, but read again. Was the symptom there before the injection check?Mad Farquhar2013-03-29 21:38:26
Obviously check the easy and cheap first, air filter, fuel filter, fuel pump, TPS setup and TB sync. I’m sure you have!
What valve clearance do you use? The OEM is too small, the valves on my Stone needed reseating at around 50k. I use 0.15 inlet and 0.20 exhaust. So compression is worth checking.
Sounds like low mileage for the year,been standing? Might take a look to see if the UJ has gone tight?
lawries2013-03-30 15:02:00
Not sure if this bike has the same throttle set up as a bellagio but my bike at the time was found to be only operating at half throttle when the control linkage was found to have seized up below the tank. I did put a few photos and notes about this at the time in the bellagio banter thread. The linkage once stripped, cleaned and lubed worked great and transformed the bike.
www.motoguzziclub.co.uk/forum/forum_posts.asp?TID=8430&KW=Throttle&PID=106897#106897
Sorry don’t have the photos anymore
guzzibear2013-03-30 13:30:15
good call on the valve clearances. On the EV the specified clearances are too tight and were published to meet noise regulations. The preferred settings for the EV from Raceco et al have been posted here but I can dig them out if that’s useful.Compression check is easy and cheap. This may point to a number of things if low.Best of luckSteve
Do the cables and linkages check too, made a big difference to both my guzzis, and I only done it for want of something to do!
Raceco clearances are 0.2 and 0.25. Intended for performance (track) bikes I think. I tried that and reverted to 0.15 and 0.2 because I noticed no difference (except noise) and wondered on the longevity of the cam followers, but perhaps I worry to much
Bet it is, what the balance pipe actually does is help scavenge exhaust gas out of the cylinders at some critical engine speed. This usually coincides with the top speed end sort of area. It does this by interrupting the uniform downpipe pipe cross section to create a negative pressure wave that goes back up to the exhaust port. If the time that it arrives coincides with the next instant of the exhaust valve opening, you get a power boost. Some designs have 2 balance pipes e.g. Le Manses and BMW R80’s, so you’ve got two goes at getting a power boost at two different engine speeds. And yes if this is injection it has no choke in the traditional sense.
Thanks Guys, will refit the balance thingy and see how she goes.
Hi Lawries,This is the post quoting Raceco’s advice from their site. I’d read it as being for general rather than race use.Agree with exercising caution and mecahanical sympathy 'thoughAll the bestSteve
Posted: 31 Jul 2012 at 14:04Raceco’s advice on tapped clearances for EV era bikes is useful. The factory settings are to compile with noise regs.From the Raceco websiteTappet clearances for two and four valve enginesTwo valve enginesTappet clearances for the Guzzi big twins should be set to 0.20mm for the inlet and 0.25mm for the exhaust. This also applies to the “modern” Guzzis such as the Sport 1100, Cali 1100i and V11. The factory settings for these bikes are 0.10mm and 0.15mm respectively, but this is to try and reduce engine noise to meet US emissions regulations. With tappets set this tight the engines have trouble ticking over and running cleanly at low revs.
guzzibrat2013-04-12 23:07:05
Crikey yes 0.1mm is < 3 thou, nearly closed up. It depends which bits expand / contract more than others, but obviously enough clearance ensures valve will be properly shut when it’s supposed to be at all foreseeable operating temperatures. From my MG manual: page 30"If the clearance is too much, there will be noisy valve operation, if too little, the valves do not close fully causing inconveniences such as: Loss of compression; Overheating of engine; Burning of valves." A Tonti is 0.22mm (0.0085"), I was told very early on to make it a loose 9 thou (0.009")