96 sport 1100

[TFinch1990]

Bought my first Guzzi this weekend a 96 sport 1100 took it out for a short test ride and found that it’s not running 100% it acts like any thing above 3000 rpms it won’t take fuel it falls on its face it also after the ride would not idle down below 2000 rpms when I first started the bike after it warmed up it idled fine any help or insite would be greatly appreciated I’m new to Moto Guzzi and is never owned a carb bike so I have a lot to learn

[Turin]

Has it sat for a while?

[Murray]

Do you know much history of the bike service etc? Is it still running the standard airbox and exhaust or has someone changed it, has it been tuned to the changes? The deloroto's were a bit notorious for not holding thier blalance (assuming its still got them) and its always effect the idle behaviour, the choke was a useless so I'd suggest not using it. On your 20 year old plus bike what is the condition of the rubber bits especailly the intake boots and the hoses than run of the intake to the electronic ignition the don't last forever and vacuum leaks cause all sorts of wierdness even on FI bikes.

With the high RPM it could be a coil breaking down although I've had a pretty good run out of mine. There is not much in the way of fuel filtration however there is a pretty basic screen under the fitting that goes into the carbs and there is also a screens on the fuel soleniods in the bottom of the tank obviously the tank needs to be empty to check this. Would also be worth checking that both fuel soleniods are opening as advertised. If you find a significant amount of gunk in the screens you'll probablly need to strip and clean the carbs obviously have a look at the condition of the fuel hoses as well. When you put it all back together some inline filters would be a good idea.

Carbed bike aren't much different for fuel injected bikes they are all internal combustion engines and they all need compression ignition and fuel in the right place at the right time to work. I have put forward some likely suggestions but without seeing the bike or having more detialed information they a bit of a guess.

[fotoguzzi]

Could it be running on only one cylinder? Maybe a plug wire came loose? Check both ends and be sure it's seated in the coil.

[rocker59]

My first thought regarding the high hot idle is check carb idle speed screws, then the balance.

The one time my '96 Sport 1100 behaved like that was a result of Dellorto carb improperly set up during a dealer service.

The problem over 3000 could be several things, so it would be helpful if you knew the history on the carb's setup by the previous owner.

[Kiwi_Roy]

Congratulations on your first Guzzi, I'm sure you will get the advice you need to get it running again.

 

Is it the carb model or the 1100i Fuel injected? Never mind I re-read your post.
I think you will need to give us some more to go on.
Does it start to miss or simply drop off in power like its starving for fuel?

Make sure that both carbs are opening.
Check the high tension leads,
Can you describe the ignition system on your bike
     Points or some form of electronic pickup
     Distributor or twin coils

Did they warn you Guzzis are addictive.

[pete roper]

Carb Sports are a bit *Special*. They have a host of oddities and weirdnesses. Remember you have just bought a twenty nearly three year old machine so at some time in its life it is bound to have been ignored, abused or both!

Firstly tell us if it's still stock? Does it have its airbox or pod filters? What brand of carburettors does it have? How many miles/kms does it have on it? Do you know if it's run for any length of time with a broken speedometer?

Their gearboxes are very fragile. Is yours particularly loud in any gear? Most particularly 3rd and 5th?

My first suggestion is give it a full service/tune and check the carburettor jetting. Make sure the trunnions on the driveshaft are correctly aligned and drain the gearbox oil through a sieve and check the magnet on the drain plug. If it looks like a Christmas tree? You have problems.

Clean the ignition pick up in the bell housing and run an extra earth from the front subframe that supports the clocks to the engine block and another, substantial one, from a bell housing stud to the battery negative terminal.

Get cracking! They are, like many Guzzis, a flawed but magnificent machine that can be made sublime, (As long as you are under fifty and built like an orangutan! )

Pete

[Mr Revhead]

Hey, nice bike! Sorry no further advice to give than the gems above, but my injected Sport arrived last week, I too immediately had issues with it, but well on the way to it being sorted now.
I do have this bit of advice, when it's not running right, just look at it. Shit they are sexy aren't they?! 

[wirespokes]

I've dealt with Dellortos a long time and haven't found them to be unreliable or going out of balance constantly. Once they're jetted correctly, the engine is tuned (ignition, valve adjusted), and the carbs are adjusted and balanced, the just run and run and run without any more attention.

First off, the high idle could be that whoever last set the carbs set them when the engine was cold. That it idles fine at start-up is the first clue. Adjust idle speed and mixture when the engine is good and warmed up after a 20 or 30 mile ride.

If the jetting is right, the choke will be needed to start the bike. That's nonsense about the chokes on these bikes being useless! A comment like that tells me the jetting was wrong and running rich at idle - if it starts without a choke. Sure, you can blip the throttle a time or two and squirt some gas down the throat that way, but I find the choke to be needed this time of year despite blipping the throttle as well. I can usually close the choke within a minute or two, but if I forget to engage the choke it won't start at all.

More data would sure help - like how many miles on the bike, condition, changes made - that sort of thing.

Congratulations getting a really cool bike. Pix?

[Murray]

I've dealt with Dellortos a long time and haven't found them to be unreliable or going out of balance constantly. Once they're jetted correctly, the engine is tuned (ignition, valve adjusted), and the carbs are adjusted and balanced, the just run and run and run without any more attention.

After 2500kms a decent chap who knew what they were doing with a screw driver could improve the way the bike ran, when it was due for a service they were usually out enough to adversly effect the idle, having said that it almost always was the idle and rarely other parts of the rev range. This was across two different 1100 sports and probablly 50k odd miles. The delortos are a decent ish 1960's carburettor but they are exactly that, a 1960's carburettor.

[yogidozer]

Let the sparkplugs give you a clue.
Old gas? Carbs. dirty? Fuel filter needed to be changed? Old plugs?
Good starting points.

[Tusayan]

After 2500kms a decent chap who knew what they were doing with a screw driver could improve the way the bike ran, when it was due for a service they were usually out enough to adversly effect the idle, having said that it almost always was the idle and rarely other parts of the rev range. This was across two different 1100 sports and probablly 50k odd miles. The delortos are a decent ish 1960's carburettor but they are exactly that, a 1960's carburettor.

The Dellortos fitted to the 1100 Sport are a product of the 70s and when introduced were the best available.  By the 90s the main issue was that they were jetted to pass emissions regulations with the expectation that they would be rejetted by the buyer.

[yogidozer]

The Dellortos fitted to the 1100 Sport are a product of the 70s and when introduced were the best available.  By the 90s the main issue was that they were jetted to pass emissions regulations with the expectation that they would be rejetted by the buyer.

I found this to be true also. Keep them clean, fresh gas, good filters air/fuel, and you'll be good to go go go 

[Tusayan]

The last Japanese carbs are better, but PHF and PHM round slides are pretty good.   Their main weakness as installed on an 1100 Sport is the very long throttle travel and stiff return springs.  Somebody at Guzzi had a thing about sticking throttles and fitted stiffer springs than Ducati in the same carbs - Dellorto (and their aftermarket arm Malossi) supplied different springs upon request.  It is true that 40-mm PHMs need a stiffer spring that e.g. 36-mm PHFs but they don't need what Guzzi installed.

[yogidozer]

The last Japanese carbs are better, but PHF and PHM round slides are pretty good.   Their main weakness as installed on an 1100 Sport is the very long throttle travel and stiff return springs.  Somebody at Guzzi had a thing about sticking throttles and fitted stiffer springs than Ducati in the same carbs - Dellorto (and their aftermarket arm Malossi) supplied different springs upon request.  It is true that 40-mm PHMs need a stiffer spring that e.g. 36-mm PHFs but they don't need what Guzzi installed.

I have a 1/4 turn throttle, different springs. No sticking of the throttle. Changed jetting, slides, needle, add fuel filters, runs great.

[TFinch1990]

The amount of information I’ve gotten so far from you all has been amazing you all have ask for more info this is what I have the bike has 26,000 on it it has set for the last 3 years and has only been road about 3,000 miles since 2005 according to the survive sheet I was given with the bike the previous owner to vary good care of it pretty much everything about the bike is in like new condition the carbs have been rejected to the non American spec as far as what’s in them in not for sure but I was told that when the bike was being road it ran grate the bike starts vary easy set the choke pump the throttle about 3 times it’s starts right up was able to take the choke off in about 30-45 sec just setting in the shop running the bike has no issue reving all the way up the issue came into play when I road it it just acts like it won’t take fuel or it runs out of fuel but if you hold the throttle in place for a few seconds it picks up and pulls like a fright train tell you go to up shift then it won’t take fuel agine I hope this info helps

[arveno]

I would just start with a complete carb dismantling/cleaning /reassembling .
Balance them properly with the specific tool so no guessing there.

After that , see if the problem still exist.

Whatever Pete says... 

Ignore the whole Debby Downer crowd    ....  you got yourself the best guzzi ever...

Ciao
Marco

[wrbix]

Ignore the whole Debby Downer crowd    .... 

Ciao
Marco

.....but, if you decide not too, and want to unload her, let me know .....

[Zoom Zoom]

I didn't read all the replies, but when I read your original post, the first thing I thought was vacuum leak. An exposed balance port, a bad boot between the carb and manifold, bad gasket between the manifold and head. I have seen those things cause the symptoms you describe.

Perhaps even before that, is checking valve adjustment. Weather or not that has anything to do with it, they need to be correct before you begin balancing the carbs.

I also did notice comments about rebuilding the carbs. If there is no obvious vacuum leak, that will be the next step.

If you want to search for a vacuum leak, take the bike outside and start it. Let it warm up to the point you can have the trouble happen and spray some starting fluid around the carbs. If there is a vacuum leak, it will be very evident when you spray in the right place. If nothing changes, a tear down on the carbs may be in order.

Say hi to the in-laws for me! Saw the pic. Nice bike!

John Henry

[RinkRat II]

    All these carburetor symptoms sounds like Ignition to me. Ohm the wires, new plugs and if its got points make sure the base plate is free and not sticking Just my $.02
        Congrats on the new to you Guzzi!
   
         Paul B

     After looking at the parts sheets, no points but clean the timing sensor of any swarf.

[blackcat]

Does this bike have the Digiplex ignition? If so, I'd look at that vacuum line to the (manifolds) carbs.

[larrys]

Since it has sat for three years the carbs may be gummed up. Pull the carburetor bowl drain plugs. What you see in the bottom of the drain plug will be an indicator of what the inside of the carb looks like. If it falling
 on its face when opening the throttle, sounds like a dirty needle and needle jet, or maybe a clogged main jet. Easy enough to check.
Larry

[Murray]

Does this bike have the Digiplex ignition? If so, I'd look at that vacuum line to the (manifolds) carbs.

Yes, has been suggested, Once you get the motor sorted out I'd suggest you check the uni joints are properly aligned and get the brake and fork fluild changed. The forks are the old school damper rod style and the condition of the fork fluid has a dramatic effect on the handling.

[rocker59]

  the bike starts vary easy set the choke pump the throttle about 3 times it’s starts right up was able to take the choke off in about 30-45 sec just setting in the shop

As mentioned a couple times above, this is a good indication that the idle speed was set on the bike before it was fully up to operating temp.  The carb'd Sport 1100 really needs to be hot before setting the idle.  When set to idle at 1050 rpm at operating temp, they're a little cold natured and do not idle that great at cold startup.

running the bike has no issue reving all the way up the issue came into play when I road it it just acts like it won’t take fuel or it runs out of fuel but if you hold the throttle in place for a few seconds it picks up and pulls like a fright train tell you go to up shift then it won’t take fuel agine I hope this info helps

Are you whipping the throttle full open at low rpm to cause this phenomenon?  Or, are you rolling it on?  These are not CV carbs.  If you whip the throttle open the Dellorto pumpers will dump a lot of fuel into the engine.  If you're not running enough RPM, the engine will bog.

[rocker59]

   Somebody at Guzzi had a thing about sticking throttles and fitted stiffer springs than Ducati in the same carbs - Dellorto (and their aftermarket arm Malossi) supplied different springs upon request.  It is true that 40-mm PHMs need a stiffer spring that e.g. 36-mm PHFs but they don't need what Guzzi installed.

It is my understanding that Guzzi selected the heavy springs because of the Sport 1100's pressurized airbox and the lack of closing cables on the Dellortos.  At high speeds the pressurized air could cause the slides to stick open.

I believe this because I experienced it a couple times on my Sport 1100, when it still had the Dellortos.  Full throttle, 100 mph, chop the throttle closed, but the slides would stick for a second or two.  It was very disconcerting.

Of course, at normal legal highway speeds, it was never a problem.

And since 2003 I've been running Keihin FCR41 carbs, which have flat slides and closing cables, so absolutely no problem.  Lighter throttle action, too.

[Tusayan]

It is my understanding that Guzzi selected the heavy springs because of the Sport 1100's pressurized airbox and the lack of closing cables on the Dellortos.  At high speeds the pressurized air could cause the slides to stick open.

I believe this because I experienced it a couple times on my Sport 1100, when it still had the Dellortos.  Full throttle, 100 mph, chop the throttle closed, but the slides would stick for a second or two.  It was very disconcerting.

Of course, at normal legal highway speeds, it was never a problem.

And since 2003 I've been running Keihin FCR41 carbs, which have flat slides and closing cables, so absolutely no problem.  Lighter throttle action, too.

Guzzi specified ultra heavy carb springs on every bike I can think of since the 1970s.  I don't believe the increase in differential pressure across the slide as a result of a very slight boost in airbox pressure would make a significant difference in slide friction.

Japanese 1990s carbs are great. 

[Devildog]

Good luck. Pics please. On buying mine I had a flat spot@3500-4000 rpm but a good mechanic rejetted, balanced and got things sorted. His rule: change only one thing at a time, and test the changes before making the next one.
All respect to Mr Roper's opinions, but I'm 62, 5'10" normal build and the bike fits fine. After 2hrs my neck and wrists complain, but it's a really great bike to ride, and great to look at too.

[yogidozer]

Good luck. Pics please. On buying mine I had a flat spot@3500-4000 rpm but a good mechanic rejetted, balanced and got things sorted. His rule: change only one thing at a time, and test the changes before making the next one.
All respect to Mr Roper's opinions, but I'm 62, 5'10" normal build and the bike fits fine. After 2hrs my neck and wrists complain, but it's a really great bike to ride, and great to look at too.

Agree 100% on the rejetting.
As far as riding position, DYK that you can swap clip-ons left to right? Raises the reach up a bit, not a stop and go/city bike by any means.

[kidsmoke]

OP is a wee lad in his 20's whose other bike is an Aprilia Futura. He'll have no problems wrangling this machine.

Good on ya Todd, good to see you here, you'll get the info you need for certain!

Kidsmoke (~aka Kip)

[TFinch1990]