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Bryan's 1989 FJ1200 rebirth in Poplar Grove, IL

Started by Waiex191, May 15, 2020, 10:34:14 PM

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Waiex191

With the hydraulics more or less sorted, time to get to the carbs.  I bought woodcreekpete's 1990 carbs.  They were missing the diaphragms so the price was very reasonable.  I set up a clean spot and an old bath towel for the carb work area.


These carbs were loosely put together so not really any drama to take them apart.  Plus they were pretty clean inside.


I was a little gun shy about removing the float pivot pins since last time I broke two of the supports.  So, I made this nifty tool.


You clamp it in the vise, line up the pin with the hole in the end of the tool, place your punch of choice (I used an old #40 drill bit), and give it a tap with a light hammer.  Both float supports are supported nicely, and this isn't even scary.  I was going to get fancier, and weld a tube on the extraction end, and thread the hole where the punch goes.  But then I came to my senses.  And with carbs in decent shape this is probably overkill.  That's ok, overkill is my nature.


The carbs were pretty clean as I mentioned, but interestingly enough the air bleed jets (or whatever they are called) were a bit dirty.  The #1 was the worst.  I've never seen one of these jets dirty at all, in my FJ or other bikes with Mikunis.  Interesting.


When I was done I covered it up with a classic aviation shirt from the rag pile.  The screwdrivers with the white tape are custom ground for the air bleed jet and the pilot jet.  


Next session I'll give the carb bodies a blast with carb cleaner and compressed air, just to make sure.  I think most of my brass is in better shape as I went crazy cleaning it.  I have 4 new float needles, the carb o-ring kit with screws from RPM, and of course the diaphragms from my old carbs.  Otherwise I'll evaluate, pick and choose the best parts and assemble.  I did verify the bowl passages for the starting circuit were not blocked.  

Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

ribbert

Quote from: Waiex191 on June 23, 2020, 11:23:48 PM

You clamp it in the vise, line up the pin with the hole in the end of the tool, place your punch of choice (I used an old #40 drill bit), and give it a tap with a light hammer.  Both float supports are supported nicely, and this isn't even scary.  I was going to get fancier, and weld a tube on the extraction end, and thread the hole where the punch goes.  But then I came to my senses.  And with carbs in decent shape this is probably overkill.  That's ok, overkill is my nature.



Well done, nothing spoils your day like snapping off a float post.  Is the hammer in the photo the one you used?

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

Waiex191

Quote from: ribbert on June 24, 2020, 04:36:24 AM
Well done, nothing spoils your day like snapping off a float post.  Is the hammer in the photo the one you used?

Noel

It is, and thank you.  I used the side of the hammer head rather than the plastic or rubber ends.  It is pretty light.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

Waiex191

Question - what should I use to lubricate all the o-rings for the fuel system?  Left to my own devices I'd probably use WD40.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

krusty

Curious. Why would fuel system O rings need lubrication?
91 FJ1200
84 FJ1100 x 2
85 FJ1100
89 GL1500
76 CB750F1
72 CB350F
63 C92 x 2
59 C76
62 C100
63 C100
60 Colleda 250TA x 3
63 Suzuki MD50
77 DT125E
77 DT175E x 2
79 DT250F

Waiex191

Just to get them installed without damage.

Another question: for the idle air screws is it needle, spring, washer, o-ring or is the washer on the bottom?

Edit: I took apart a couple of my old carb idle air screws.  O-ring on bottom.

To get the plug out I drilled a #40 hole in the plug, screwed a #4 screw into it with a little WD-40 to lube the threads, and used the screw to push out the plug.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

ribbert

Quote from: Waiex191 on June 25, 2020, 04:04:13 PM
Question - what should I use to lubricate all the o-rings for the fuel system?  Left to my own devices I'd probably use WD40.

I've never heard of anyone wanting to this but as Red pointed out yesterday, WD40 is 50% kero. The bulk of the remainder is some sort of Paraffin derived oil that is the water disbursing agent, it has no enduring lubricating qualities. It is a penetrant, not a lubricant. IMO.

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

Waiex191

Quote from: Pat Conlon on May 24, 2020, 12:42:24 AM


Back to setting your idle mixtures by hand.....Randy at RPM told me about the "Thumb Nail" method of idle mixture adjustment.
The key to getting equal air/fuel idle mixtures between all 4 carbs is to: Start the adjustment with all 4 needles in the exact same position.
You do this with your thumb nail.
When your carbs are off, screw IN the idle mixture screws until the tip pokes into the throat. Now take your thumb nail and feel the protruding tip, now with your other hand turn out the mixture screw until the point where your thumb nail slides off the tip of the mixture screw. *stop*
Do all 4 carbs like this....Now all 4 carbs will have the air/fuel mixture screw at the exact same starting position.

I have found about 1.0 to 1.5 turns OUT from this position is a good starting point for final tune.

To demonstrate my point about the uneven threads, after setting all 4 screws with your thumbnail, they are all even....now turn IN the screws and count the number of turns in until they are "lightly seated".
I'll bet you a jelly donut you will get slightly different counts between the carbs.

You can write down these differences in your log book, and/or mark them with a felt pen on the caps of the carbs.
From the thumbnail test point all carbs are even:
If one carb's mixture screw goes IN one full turn until lightly seated that carb is marked 0
If one carb's mixture screw goes IN only 3/4 turn....that carb is marked -1/4
If one carb's mixture screw goes IN 1 1/4 turns until lightly seated.....that carb is marked +1/4
This is just for future reference, down the road, in case you get the number of turns mixed up and have to go back to the starting point with all the needles at the "lightly seated" position, you have the needle position differences recorded.


While the carbs are off, use your thumbnail and set those air/fuel idle mixture screws exactly the same between all 4 carbs...as a starting point for fine idle mixture tuning.

Thank you Randy.

Pat

Pat/Randy/anybody,
I've just set my idle air screws using this procedure.  Three of them went in 2 7/8 turns to lightly seated, and one was about 2 3/4 turns.  So after these are set, how do you do the final adjustment that is hinted at here?
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

Waiex191

Quote from: ribbert on June 25, 2020, 09:36:26 PM
Quote from: Waiex191 on June 25, 2020, 04:04:13 PM
Question - what should I use to lubricate all the o-rings for the fuel system?  Left to my own devices I'd probably use WD40.

I've never heard of anyone wanting to this but as Red pointed out yesterday, WD40 is 50% kero. The bulk of the remainder is some sort of Paraffin derived oil that is the water disbursing agent, it has no enduring lubricating qualities. It is a penetrant, not a lubricant. IMO.

Noel

True, but I only need it to lubricate long enough to assemble. With a little WD-40 on the float valve body it slides into the bore nicely.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

ribbert

Quote from: Waiex191 on June 25, 2020, 10:24:41 PM
Quote from: ribbert on June 25, 2020, 09:36:26 PM
Quote from: Waiex191 on June 25, 2020, 04:04:13 PM
Question - what should I use to lubricate all the o-rings for the fuel system?  Left to my own devices I'd probably use WD40.

I've never heard of anyone wanting to this but as Red pointed out yesterday, WD40 is 50% kero. The bulk of the remainder is some sort of Paraffin derived oil that is the water disbursing agent, it has no enduring lubricating qualities. It is a penetrant, not a lubricant. IMO.

Noel

True, but I only need it to lubricate long enough to assemble. With a little WD-40 on the float valve body it slides into the bore nicely.

Fair enough. If it did the job you wanted, that's all it had to do.

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

Waiex191

Here is my RPM o-ring and screw kit. So many parts I had to separate them out.  I also bought float needles and pivots from RPM.


Today I installed the emulsion tube, main jet, pilot jet, air bleed jet, air bleed screw, float valve seat, and choke on all carbs.  I have set the float height on #1.  Whilst setting it, I found a #40 drill bit is the perfect diameter. 


After setting it I drove the real pin home and double checked.  It was good.


One carb bottom is buttoned up.  Three to go.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

Waiex191

Noel,
I didn't want to dilute Mark's thread so I'm asking the question in my own.  Are those stock pipes?  Once you polish how much maintenance is needed to keep them looking good?
Quote from: ribbert on June 26, 2020, 08:00:20 AM

I gave up on exhaust coatings, not because of cost, but whatever I used failed at the top bend on the headers given enough miles.

Why don't you just polish them, for free. They look good, the finish lasts a surprisingly long time and it's easy to touch them up while fitted. You also mentioned painting the calipers, I don't think they're painted. Fred (and others) will know for sure.

This is what lurks beneath...


After they had a bit of colour from use

Noel


Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

RPM - Robert

We use a dab of motor oil when installing the o-rings.


ribbert

Quote from: Waiex191 on June 26, 2020, 09:11:22 AM
Noel,
I didn't want to dilute Mark's thread so I'm asking the question in my own.  Are those stock pipes?  Once you polish how much maintenance is needed to keep them looking good?



Yep, bog standard.....

   

This shows the pipes as they came off the bike, wet rubbed (to get rid of the OEM coating) and polished.

I don't find them too bad to keep looking good. I have smaller tapered, cylindrical and ball shaped buffs for my drill that make polishing in place easy, the trick is to not let them get too bad. I probably take them off only every 70 or 80k and machine polish them.

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

Waiex191

I'm about to set my 4th float. All of them have measured about 20.6 mm before I adjusted anything.  Old floats, seats and new needles.  Seems odd I have to adjust them so much.  Am I just being paranoid?  I have read all the carb files and am checking with the carb bodies about 70 degrees, so the float is not pressing down on the spring.  Definitely not the first floats I've adjusted.  I'm using my calipers set for 22.3mm.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL