Trouble Shooting 101?

[Redneck]

Okay we hear a lot of talk about cleaning carbs, checking float heights, and adjusting valves. So here is a series of questions that once answered I am hoping will not only help me when I go to start the Shadow Bike but others in their efforts to keep or get GS bikes on the road.

What kind of symptoms can I expect from the following
(if everything else were working, I believe in one problem at a time)

1. Valve clearance too tight? Too Loose?

2. Float heights wrong in Carbs?

3. In need of Carb Cleaning?

4. What should I expect if my bike is running too rich? Too Lean?

5. What if I have a bad seal around my intake boots or my air box?

I figure that enough of you have worked on these bikes long enough that you would be able to explain these questions and hopefully help those who are new to wrenching. Thank you for your time.

[BassCliff]

Hi,

It's a 30 year old motorcycle. You should just assume that there has been no maintenance done for at least 20 years. Then perform *all* the required maintenance. (Hint: There are two lists in your "mega-welcome".) If that doesn't make the bike run like new *then* you can start troubleshooting from a known baseline.

I've seen so many new members try to get by with doing the bare minimum according to the "symptoms". It usually doesn't work that way because all the systems are related and older bikes usually have multiple problems and neglected maintenance. Please do not do a disservice to new members by encouraging a single "silver bullet" fix. Be realistic.

If you really want answers to your questions, simple searches will reveal all. They have been answered hundreds, if not thousands of times. If you don't feel like searching the forum or doing your own research, just read the research I've gathered on my website for your convenience.

Thank you for your indulgence,

BassCliff

[bwringer]

Whether you believe in one problem at a time is immaterial -- old unrestored bikes inevitably have more than one problem at a time.


Anyway, here goes -- assuming everything is perfect except each of the below. Which is a rare condition indeed:

1. Valve clearance too tight? Too Loose?
Too tight: Hard starting when cold -- the valves "leak" at low RPM and this jacks up the vacuum "signal" to the carbs. VERY common. If and when the bike starts, this may also cause backfiring at higher RPM.

Too loose: "knitting needle" noises from the top end. Rare problem, usually caused by someone who confuses inch feeler gauges with metric. .001" = .0254mm. On bikes with screw and locknut adjusters, forgetting to tighten the locknut can lead to a loose valve clearance -- usually just one.


2. Float heights wrong in Carbs?
Fuel starvation or flooding if it's very wrong (or if a float is damaged). If float height is close to ideal, it can be fine-tuned in .5mm increments to fine-tune off-idle and low midrange. Inconsistent float heights are common -- set them all the same. On CV carbs, incorrect measuring is also VERY common -- measure at step, not overall float height.


3. In need of Carb Cleaning?
Pilot (idle) jets clog first, so if the bike won't run unless the choke is on, the pilots are clogged. Inconsistent idle can point to one or two clogged pilots out of the set (usually the carbs on the left). Inconsistent idle can also point to lots of other issues, such as intake leaks, bad idle mixture screws or o-rings, etc.


4. What should I expect if my bike is running too rich? Too Lean?
Question is irrelevant unless you also know throttle opening, loading, and a few other variables.
In general, too rich leads to poor mileage and sooty plugs. Can be caused by clogged or over-oiled air filter.
Too lean -- engine runs hot, white or glazed deposits on plugs, burned exhaust valves. Usually caused by failing to rejet for intake/exhaust changes and intake leaks.

5. What if I have a bad seal around my intake boots or my air box?
See "too lean" above. Your engine will probably die horribly soon. Inconsistent idle and running, running too hot, white or glazed plugs. Burned exhaust valves.


Again, the point must be made that it's very, very rare for these problems to occur in isolation. There are excellent reasons so many of us preach "the list" -- until you have accounted for all the basics, you're making uneducated guesses.

[BassCliff]

Thank you Brian,

I should just delete my last paragraph. It sounds mean. Maybe I shouldn't post when I'm tired and hungry.

Nah, I'll leave it there to remind me to be more gentle.



Thank you for your indulgence,

BassCliff

[tkent02]

Cliff, it's OK. We all know how scary you really are.

[Big T]

Looks like someone needs to read the Top 10 Newbie Mistakes!

[Steve]

Cliff, it's OK. We all know how scary you really are.

.

[Nessism]

Geeze Cliff, In your first post you sound like me...then you reverted back to your ol Mr. Pollyana self. You are a model to behold.

[BassCliff]

Hi,

Thanks for nothing.

Ed, my friend! You're killing me!



Thank you for your indulgence,

BassCliff

[Redneck]

Well Basscliff the point of this was not to have people avoid the maintennance or not think that they only have one problem. It was more or less kind of like saying hey I did all the maintenance but I am still having this problem. Did I possibly do something wrong. What would those signs be. I have been around long enough and know that I can find out how to do all the maintenance I need to get these bikes up and running just by using your super awesome megawelcome and reading the top 10 newbie mistakes. What isn't often times said is what the bike does if you don't do these things or if you do them wrong. This was more of a guide to understand if the maintennance was done wrong this is what it will sound like.

Did I ramble on and clutter up my point. Hope not. Brian thank you for answering my questions in a very nice concise manner.


Paul

[Allie]

Even Richard Nixon has got soul.
And even Basscliff can be grumpy.

[Big T]

Did I ramble on and clutter up my point. Hope not.

Yep, you did

If a new user does all the maintenance and still has a problem, he/she can post that problem up in the appropriate forum for advice.

Or, better yet, use Search to see if others have had the same problem and what their solutions were

[Redneck]

Oh well was just trying to put sypmtoms with causes in one convenient spot. I apologize if I confused anyone was just trying to make a thread that would prove helpful to someone. I like knowing what each of the maintenance items we preach will do for a bike and what the bike would do if it was not done or done properly.

[BassCliff]

Hi,

I guess my point was that if you take the time to properly maintain your bike nothing on that list would be an issue.


Thank you for your indulgence,

BassCliff

[spyug]

I agree, its best IMHO is to a) research the problem first in the archives and if no solution appears then b) post the specific symptom(s). In my experience, there are very few symptoms that point unerringly to a particular problem so to have a list of them is not going to simplify the diagnosis and repair and ,as mentioned, may even muddy the water.

As in medicine, I think the best help for a proper diagnosis is a clear concise description of what is going on and what may have been done to cause or fix it. Too many newbs make blanket statements in the hope that someone can laser point to the problem. Something like, "my bike won't start after I brought it home", is far too vague and there could be at least 20 reasons why it doesn't start. A point by point summary of everything that happened from the last time it ran would make it much easier to figure it out, I think.

My 2 cents on the subject.
Spyug