What do I tell the shop mechanic?????

[Guest captain nemo]

I rely on you guys. Your advice is based on much experience with the V11. I do not claim to know anything about them. I just love to ride 'em. I am also convinced from a couple experiences - as well as an experience my riding partner had - that I am no longer going to simply let shop mechanics just take over my bike. They do not really know what is best some times although they are convinced they know all and see all.

 

OK, here's the problem: My Guzz is running very sweet, but I can see that the right cylinder is either running rich or there is a ring problem. When the bike is idling, you can see smoke out of the right pipe, but not the left. Also, the right spark plug is very black and coated with carbon while the left side looks about right. I need to lean out the right side I think.

 

Questions:

 

1. The manual only shows an idle adjustment for the throttle bodies - and this requires a vacuum gage. It there any adjustment for basic fuel mixture outside of the PC111? In other words, can I tinker with it here SO THAT I DON'T HAVE TO TAKE IT IN TO THE SHOP?

 

2. I'm concerned the shop guys will throw my map off. Like I say, the Guzz is running well. I suppose it is vibrating more than it has to due to some unbalance. Do I tell them to balance the TBs, or do I tell them to set the bad right side with the same settings as the good left side? Could they even do that?

[Guest dkgross]

just MY opinion....I've never had anything happen that I couldn't tell Micha at Moto I about that he didn't fix immediatly. And if it's even close to being something that's a warantee issue, he tells me. I really do trust him completely with my bike.

[dlaing]

1. How rich the cylinders run can be controlled by:

a. balance, ie the harder it pulls the leaner it runs.

b. idle bypass screw, with individual control for each cylinder.

c. MDS Motorcycle Diagnostic Software. For a few hundred bucks you can buy software that can adjust the 'trim'. I believe this mostly effects idle mixture, but is also usefull for determining that the TPS is set properly and that other sensors are functioning properly.

http://www.technoresearch.com/Diagnostic.htm

 

Note that many things can cause one cylinder to run rich or lean.

If one cylinder is off I would ideally adjust the valves first and then the throttle body balance.

However, many times I just adjust the throttle body balance because it is more prone to falling out of whack. I just bought a TwinMax. It works great, so far. Avoid dial gauges. The mercury sticks also work great, but have environmental, health and mechanical risks. If you get real good, you can do it by ear!!! But that may be reserved for Master Guzzi Gurus

 

Can you tinker with it? If you mess up, your warranty and bike may be messed up, but aside from that, go for it.

 

2. They probably won't mess with the map on your PCIII. But if they adjust TPS it could throw it for a loop. Also adjusting valves to a different spec could throw the effect of the map off.

Did you have a map custom made on a dynometer?

If you ever do, it is a good idea to know what the TPS and valves are set to.

If you explain to the mechanic that you have a custom map and that you do not want the TPS changed, and that you are concerned that the valves not be changed so much that your map is thrown off, they SHOULD take good care of your baby.

Moto International has an excellent reputation, so you should be fine. But do talk to them about your concerns. They may not know that people use valve specs and TPS specs that work fine but are not to factory spec. If they cannot relate to that, find someone else.

The safest thing would be to tell them your concerns and that you only want a quick throttle balance without messing with trim, or TPS.

If all else is well, they should be able to balance it in five minutes.

They might not want to let you know it only takes five minutes.

If that is the case, ask them why it takes so long.

The balance should clear up the mixture problem. If not, it will need a proper tune up or more.

[Mike Stewart]

Captain,

 

Before doing anything, when was the last valve adjustment? This is the most overlooked adjustment on any engine with an adjustable valve train. It effects engine compression,cylinder balance and even the fuel mixture. They all work hand in hand. The valve adjustment in my book is the starting point for any Guzzi driveability issue.

 

Heck, why not ride down to the Bay Area and I will check it out for you!

 

Just a thought,

Mike

[Guest captain nemo]

Thanks everybody. Mike - I used to live in Mill Valley right by the Golden Gate Bridge.

 

Well, I set the tappets two weeks ago. Actually I just checked them and found that they were both set at 15 intake and 20 exhaust. It seems to run well so I didn't change it. At least they are set the same.

 

Dlaing, are you suggesting that I can set the valve tappets differently from one side to the other? That I can have the right jug at values X and the left jug at values Y? I never heard of that.

 

From what I understand what everyone has said, I can adjust the idle screw and this affects the mixture? Would clockwise direction mean more gas and counterclockwise mean less gas?

 

I think I might try this first and then if I have problems, take it in for a simple TB balance.

[dlaing]

Dlaing, are you suggesting that I can set the valve tappets differently from one side to the other? That I can have the right jug at values X and the left jug at values Y? I never heard of that.

 

Nope, I am suggesting that if they are not the same from side to side, it may cause one cylinder to run rich or lean. By different I meant that US settings are one thing, world settings are another and raceco are still another, and all are proper. You may also go between the settings.

It is possible that assymetrical valve adjustments may have benefits, but I would reserve that type of adjustment to a mega genius, or someone with great equipment like a dyno and emmision analyzer, and lots of time.

Although some would argue that the US spec and or the RaceCo spec are too extreme in either direction. I believe US spec is 0.05mm intake and 0.10mm exhaust while RaceCo is 0.20mm intake and 0.25mm exhaust. I would stick with what you have it set to, as that is what I use. Not that other settings are wrong. But you should set it to what it was dynotuned at, assuming it was dynotuned.

As Mike suggests, valve adjustment is the best starting point.

I only do throttle bodies first, because it only takes a minute or two to check, while valves take me much more time.

It is important to adjust the throttle bodies after the valves are adjusted, and I am told when the engine is at operating temperature.

[docc]

Agreed on the throttle body balancing. Also to balance "off idle" like 2500-3000 rpm.

 

Dave Richardson's Guzziology has agood TB balancing procedure . Also, he recommends a 'jam nut' on the thumb wheel to keep the linkage in place.

 

You would think that particular shop would be using those procedures.

 

Nuthin' happier than a Guzzi twin with perfect sync.

[Guest dkgross]

like I said...everytime my bike leaves Moto I, it purrs and runs great.

 

 

[al_roethlisberger]

Agreed on the throttle body balancing. Also to balance "off idle" like 2500-3000 rpm.

 

Dave Richardson's Guzziology has agood TB balancing procedure . Also, he recommends a 'jam nut' on the thumb wheel to keep the linkage in place.

 

You would think that particular shop would be using those procedures.

 

Nuthin' happier than a Guzzi twin with perfect sync.

 

 

.... agreed on Guzziology

 

 

And get a TwinMax A bit pricey, but a good investment. Once you figure it out, a TB balance is no more painful than checking the air in your tires before a ride.... about a 10 minute procedure.

 

al

 

 

P.S.

 

And I cannot more heartily concur with Mike in regards to checking and finding the correct valve settings for your bike. In my case, that CURED the problems I was wrestling with for months while the shop continued to dink around with unrelated issues <_>