Smog question

[SaturationDyes]

So my bike was desmoged when i got it but it wasnt completly finished. I an wondering what to do with the three ports on the back of the gas tanks.
Thanks

[Jim __]

When sitting on the bike....

Left Port (Red Dot #3) - This was a fuel return line and goes directly into the tank.  It MUST be securely plugged.  If the bike is dropped without plugging this port you may get gas pouring out.

Center Port (# 7) - This is attached to the spill tray surrounding the gas cap.  Put a hose on this one and run it behind the air box to the right side of the bike.  You should find a hoop to run it through so any gas spilled while filling up, or water, will drain to the ground (see attached pic).

Right Port (Blue Dot #4) - This is a tank vent.  I can be plugged since the gas cap also has a vent, left as is with no hose or connected to the left port (instead of plugging the left port).  Only downside to looping it to the left port is if the gas cap vent should become clogged, which sometimes happens, you'll create a vacuum in the tank and fuel won't flow to the carbs.

I also included a pic of how everything used to work before it was removed. 

[SaturationDyes]

So another question would be what all vac lines off the carb do i block or route somewhere. Currently have just the one line going to the petcock.

My newest issue is the bike will start and idle but as soon as you touchthe throttle it dies instantly. A friend sugested that magbe the carbs need a vac line because they are cv carbs. And after looking through the manual he thought i needed a vac line to operate the carb. He said maybe without the vac line when you open the throttle youre just openjng the butterfly and introducing to much oxygen and the throttle slide/needle isnt opening.

Any help is greatly approciated.

[MAN OF BLUES]

If you pulled cali stuff off, and plugged the airbox hole, and only one line is going from a carb, to the petcock, that is all that there is... your friend has no clue about the carbs from what you have said here...
They don't need anything but clean air, consistant clean fuel, and correct valve clearances to operate as they are..
Sumpin other than that, and we can't diagnose over the net, just make sure all 3 unused carb nipples are correctly plugged, and not drawing in air.

This being said, you have contaminated fuel, and blockages in the primary circuits within the carbs, preventing them from drawing fuel thru the low speed circuits just off idle. Simple water condensing in the tank, or having been there all along, and once the tank is removed and shaken a bit, it migrates to those circuits, is the major issue.

[SaturationDyes]

Gonna pull the carbs off again and give them a full cleaning. Got it running again yesterday with another friend and he said the low speed circuits were clogged. Also a chance the petcock isnt working porperly. Was able to get it to rev some when i switch it to prime. So maybe the on section isnt allow enough gas through.

[MAN OF BLUES]

Gonna pull the carbs off again and give them a full cleaning. Got it running again yesterday with another friend and he said the low speed circuits were clogged. Also a chance the petcock isnt working porperly. Was able to get it to rev some when i switch it to prime. So maybe the on section isnt allow enough gas through.

Well, I'm glad your friend correlates exactly what I said above. After you clean all the passages, remove the primary jets and clean them completely, along with the circuits that deliver fuel to the idle circuit (the small holes in the throat ahead of the throttle plate), make sure you agitate the fueltank, and dump it out, add more fuel, shake and dump that also, to remove all the contaminants from the tank, before reinstalling it all...
You likely have moisture in that tank.

[SaturationDyes]

Thabks for your help. It will be a couple weeks before i can try and remedy this. But will post results.

[Jim __]

When you do get them clean, go to wally-world and pick up a gallon of TC-W3 (2-stroke marine oil) for about $13.  Whenever the bike is going to sit for more than a week, or less in warm temperatures, add 2 - 4 oz. to a full tank of gas and run the engine to circulate to the carbs.  These carbs are prone to clogging the low speed circuits when the gas evaporates from the bowls.  The TC-W3 trick, from the carb guru Steve In Sunny Florida , does wonders in preventing the evaporating fuel from skinning over and clogging these small passages.

[Cholla]

I wonder why 2 stroke engines get gummed up when using this oil?
Just wunderin...

[MAN OF BLUES]

I wonder why 2 stroke engines get gummed up when using this oil?
Just wunderin...

Well, back in time when 2 cycle engines were common in motorcycles, and prior to the miraculous invention of pumping correct amounts of oil into the intake tract, it was solely the fault of the operator.... usually a teenaged kid, who couldn't figure the correct ratio of specific oils to gas quantities...
Coupled with incorrect jetting and poorly adjusted carbs, dirty air filters, and incorrect spark plug choices based for specific operating conditions...
The resulting "concert of errors", coupled with intermixing different manufacturers oils and mixtures incompletely and letting them sit, produced the outcome.

It wasn't the oil, it was lack of following directions, and correct procedures.

And they really didn't "gum up" , letsnjust say they became an oily mess, which fouled plugs, exacerbating the issues.

[Cholla]

I am not talking about way back when. I am talking about today with modern 2 cycle engines.
If this oil is so good at keeping carbs clean why doesnt it work on chain saws and weed eaters?

[Summit670]

I am not talking about way back when. I am talking about today with modern 2 cycle engines.
If this oil is so good at keeping carbs clean why doesnt it work on chain saws and weed eaters?

I've had the same thought.   Maybe tcw 3 is different than those?

[Cholla]

TCW3 is ashless. Only real diff

[Jim __]

There's a big difference between 40:1 (weed eaters) and 256/512:1 (recommend range for Connies) when it comes to available oil to gum things up (ok, make it an oily mess) after the gas evaporates.

[MAN OF BLUES]

There's a big difference between 40:1 (weed eaters) and 256/512:1 (recommend range for Connies) when it comes to available oil to gum things up (ok, make it an oily mess) after the gas evaporates.

Hehehe
Coupled with the fact that the carburation systems are totally different...

But yes, the ratio is the issue.  Or non issue when dumpin an ounce or even 2 in a 7.5 gallon tank for storage.  480/960 :1 is not a problem...
Most people have more water than that in thier tank.....

[Cholla]

But the oil doesnt go away. If it keeps 4 strokes from varnishing and leaving nasty deposits it should work on all engnes.
Give us scientific reasons backed with scientific evidence why this is.  Not opinions please.

[Jim __]

It's magic.

[RFH87_Connie]

I haven't had a 2-stroke dirtbike "gum up" in 25 years.  My cousins, that's a different story.  I am sooo tired of "cleaning" their bikes.  I do take mine down one every year or so and at least check or replace the rings (required maintenance).  At that time it gets a port cleaning and head scrubbing too that removes any built-up carbon.  If you consider a dirtbike gets about 4 ounces per gallon vs. the C-10 getting 2 ounces per tank (and only when you think you want to add some), you're talking about 2 entirely different things.  Dirtbike tank at 3.5 gallons gets about 11 ounces for trail riding when I mix it (about 40:1).  Multiplied by maybe 20 tank fulls during the season, is about 2 gallons of oil in a year.  Even more if you ride more.  There are impurities that will slowly build up.  I think the "cleaners" in gasoline break down the oil if not used soon enough causing more build-up so I don't mix too much at a time.  The C-10 may see 10 ounces from me in a year.  That's a considerable amount less of 2-stroke oil in between the doses, so it is getting washed clean by "pure" gasoline I would think during the time when it is not in the tank.  Probably the small amount of acetone in gasoline helps.  At the same time, the 2-stroke never gets a break.  The cylinder is constantly bathed in 2-stroke oil.  It's also ran at high-heat and high-rpm.  I almost feel sorry for it but I love the sound of an RM400.

Then again, maybe I'm just lucky and these are still not distinct scientific reasons either, more so processes.  I did stay at a Holiday Inn Express last night.  As for the tip of the exhaust pipe - we won't discuss the varnish on it.