Gl 1200 Secondary Air System-USA models

[bronko37]

backlander » Mon Feb 02, 2015 1:36 pm[/url]":1vntceeg]
I don't see any bronko, looking at the diagrams. Straight shot from #4 to the slow air valve.

Ok so i was outin the garage lookin over that carb. I pulled the emissions box off the bottom. I knew there was one other line and I am not sure what its for. There is a vent that goes from carb num 4 up to the black ignition controll box. Im not sure if it is emissions related or what it does. But it definitly goes from carb 4 to the black box.

 

[joedrum]

vacume advance signal the black box uses and not related

 

[bronko37]

So this vacuum line has nothing to do with the emissions control we are discussing? I should replace all Hess vacuum lines while im in there as well. That way i know if I get a lot of backfire its not vacuum line related

Read the pics from the bottom up. Sorry they posted reverse of what i intended

 

[bronko37]

On a separate note about the plug needed for the afterburner valve, do you think the factory holes will be enough to hold the plate down securely to block the plug? My plan is to machine a plug with a flange that will bolt to the original hole locations but my concern is that the holes are not 180 degrees apart. There will also be a snug fitting boss that will go down as far as i can into the bore. I also have a brand new oring from the randakk kit i purchased.

Thoughts?

 

[backlander]

No, that first pic of vacuum line is part of the Vacuum advance for the ECM, the 1200 ECM uses electronic advance in 1st thru 3rd gears and the gear selector switch sends a signal to the ECM in 4th -5th gear and the ECM uses vacuum advance in those two gears. Just make sure that that vacuum line has no cracks in it, mine did and had to be replaced. That's the correct port on #4. If the cover plate is thick enough to have no flex the two bolts should be sufficient along with the 0-ring.

 

[bronko37]

backlander » Mon Feb 02, 2015 2:25 pm[/url]":1yesn6mi]
No, that first pic of vacuum line is part of the Vacuum advance for the ECM, the 1200 ECM uses electronic advance in 1st thru 3rd gears and the gear selector switch sends a signal to the ECM in 4th -5th gear and the ECM uses vacuum advance in those two gears. Just make sure that that vacuum line has no cracks in it, mine did and had to be replaced. That's the correct port on #4. If the cover plate is thick enough to have no flex the two bolts should be sufficient along with the 0-ring.

Like i said, i will replace all the vacuum lines so we get a true idea of the final result. Gonna be a bit yet tho, its inly February and we got 16" of snow yesterday.... I still need to tear into the carbs themselves which has my head hurting. For some reason this rack is intimidating me much more than my 76 rack did. I think its all the tubes and such between each carb. Oh well, ill just do one bank at a time and plug thru it.

 

[slabghost]

Be very careful removing the carb tops. The diaphragms are easy to tear and not cheap if you find replacements.

 

[backlander]

Like V said, be careful with slide tops, actually the 1200 carbs are very easy to go through.

 

[bronko37]

Ok gang, i made some progress today on this project.

First i made the block off plate out of 1/2" thick material. This will allow me to still use the stock screws for mounting along with the fuel line clips. The plate was surface ground on both sides to ensure a good seal against the o-ring. I simply traced out the basic shape. The only real reason this needs to be done is so you have adequate clearance for the choke linkage to still operate fully. Plate mounted up perfectly and covers the entire surface.

Second I made some plugs out of aluminum to take the place where the secondary lines connected. I chose to make these for two reasons. First, i did not like the idea of cutting off and welding the original plugs just incase this does not pan out i can still reattached the original system. Secondly, I wanted to take up the space so there was not a void under neath the intake runner where the plug used to be. This way, at first glance you would not be able to tell that any modification was made.

Now i simply need to fully clean each carb body and run a straight shot from the nipple on intake 4 to the slow air cuttoff valve. This should make the carb rack much much easier to reinstall. Any performance benefits have yet to be revealed. Personally I do not think that this removal will have any adverse affects seeing as how there are people who have done single carb mods on this engine and did not include the secondary air supply.

So far so good. :builder:

 

[joedrum]

great work

 

[Ansimp]

Excellent :good:
How much for a set shipped to Oz? :yes:

 

[dan filipi]

Those plugs is perty!

 

[bronko37]

Ansimp » Tue Feb 03, 2015 5:53 pm[/url]":23y23npj]
Excellent :good:
How much for a set shipped to Oz? :yes:

If it all works well we can work out widdlin you up a set Ans...

 

[flash2002]

I see you guy's are going to turn USA bikes into Canadian bikes, :good: it's a good start. :hihihi:

 

[bronko37]

Does anyone know if there is a different jetting between the USA and the Canadian models of the same year? Im runnin an 84 aspencade with this experiment. Im not sire of the jet sizes but i can fugure it out. Just wondering if there is a difference.

 

[backlander]

the 1200's non California model should have 108 Main jet and 35 slow jet. I'm pretty sure the California models used 105 Main jets.

 

[bronko37]

backlander » Tue Feb 03, 2015 7:56 pm[/url]":3lz1817z]
the 1200's non California model should have 108 Main jet and 35 slow jet. I'm pretty sure the California models used 105 Main jets.

Any idea about the Canadian models Mike?

 

[backlander]

Not a clue, sorry. That's some great looking work your doing.

 

[backlander]

Update, 1200 service manual says 84-85 main jet is 108, after 85 Main jet 105, california 84-85 it's 125, california after 85 it's 102.
Slow jet 84-85 is a 35, after 85 it's a 40.

Looks like a misprint on the 84-85 california model, 125 seems like a bit much.

 

[bronko37]

backlander » Tue Feb 03, 2015 8:06 pm[/url]":2iijqseh]
Update, 1200 service manual says 84-85 main jet is 108, after 85 Main jet 105, california 84-85 it's 125, california after 85 it's 102.
Slow jet 84-85 is a 35, after 85 it's a 40.

Looks like a misprint on the 84-85 california model, 125 seems like a bit much.

Putting all the California stuff aside, why did Honda keep tinkering with the jetting after 85? The engine and carb set up was the same was it not? Did the gearing or something change after 85?