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Carb Swap FJ1100

Started by krusty, April 16, 2021, 05:38:43 PM

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krusty

A few years back I tidied my then newly acquired '84 FJ11 after it had been stored 9 years outside in the weather by the PO. At the time I cleaned the carbs and jets, or so I thought. When I had it running t was obvious I'd missed a little dirt in the low speed system as it would stumble a tiny bit if I opened the throttle too quickly from low rpm. I put up with it as it was not so bad to be a problem or be irritating. A few months ago the problem worsened so I decided to do a carb swap-out with a spare set.
So today I did the job but was not happy with the result. The replacement set would only run on #3 and #4.
The spare set came of another '84 I have with the top end torn down waiting for me to fit a couple of new valves. The carbs were working fine when I removed them and I drained them dry at the time. So it looks like I'll be doing some ultrasonic cleaning. As it happens I have a friend who offered me a loan of his US cleaner which can take the full rack - which is good - as I have a third set I'd like to do also. Always good to have a spare.
Back to #1 & #2 not running (checked with IR thermometer) is there some physical connection between the two that could be the problem?

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 my experience - I had an issue with #2 and #3.  They both had their pilot jets re-clogged.  It's probably something easy like that and unrelated to their proximity to each other.
Bryan
1989 FJ1200
1981 Suzuki GN400
Poplar Grove, IL
 

Pat Conlon

Quote from: krusty on April 16, 2021, 05:38:43 PM
....Back to #1 & #2 not running (checked with IR thermometer) is there some physical connection between the two that could be the problem?


#1 & #2 share the same branch of the fuel line. Perhaps there is a pinch? Is the fuel line routed correctly?
http://www.fjowners.com/index.php?topic=18286.0

Electrically #1 & #2 are on different pick up coils and main ignition coils.

If the fuel line is ok, then I would look at something internal to the carbs, like Bryan mentions.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

Sparky84

Quote from: Pat Conlon on April 16, 2021, 05:50:19 PM
Quote from: krusty on April 16, 2021, 05:38:43 PM
....Back to #1 & #2 not running (checked with IR thermometer) is there some physical connection between the two that could be the problem?


#1 & #2 share the same branch of the fuel line. Perhaps there is a pinch? Is the fuel line routed correctly?
http://www.fjowners.com/index.php?topic=18286.0

Electrically #1 & #2 are on different pick up coils and main ignition coils.

If the fuel line is ok, then I would look at something internal to the carbs, like Bryan mentions.

Did you loosen the float bowl screw? Just to check that there was fuel in them to rule Pats comment above?
1984 FJ1100
1979 Kawasaki Z1300
1972 Honda CB750/4 K2

krusty

Quote from: Sparky84 on April 17, 2021, 04:01:38 AM
Quote from: Pat Conlon on April 16, 2021, 05:50:19 PM
Quote from: krusty on April 16, 2021, 05:38:43 PM
....Back to #1 & #2 not running (checked with IR thermometer) is there some physical connection between the two that could be the problem?


#1 & #2 share the same branch of the fuel line. Perhaps there is a pinch? Is the fuel line routed correctly?
http://www.fjowners.com/index.php?topic=18286.0

Electrically #1 & #2 are on different pick up coils and main ignition coils.

If the fuel line is ok, then I would look at something internal to the carbs, like Bryan mentions.

Did you loosen the float bowl screw? Just to check that there was fuel in them to rule Pats comment above?
That was something I had made a mental note to do but promptly forgot, thanks for reminding me. This morning I stripped out the carbs I took off and everything inside was clean as a whistle, not a speck of anything in the bowls. On Monday I pick up the ultrasonic cleaner which my mate says can possible accommodate 3 banks - it has a 50 litre tank. Meanwhile I'll pull the carbs of the spares bike.
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

krusty

I  just braved the cold and the rain and went out to garage and loosened #1 drain screw and fuel ran out. Maybe tomorrow I'll check for spark. It was too cold to stay out there and, tonight I ran out of LP gas for heating so I may be in bed early.
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

ribbert

Quote from: krusty on April 17, 2021, 04:41:10 AM
I  just braved the cold and the rain and went out to garage and loosened #1 drain screw and fuel ran out. Maybe tomorrow I'll check for spark. It was too cold to stay out there and, tonight I ran out of LP gas for heating so I may be in bed early.

It's about time you guys wised up and moved to Victoria  :biggrin:.

Down here in Autumn is the best place in the world, I spent 4 days last weekend in the High Country, just magnificent.

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"

Sparky84

Quote from: krusty on April 17, 2021, 04:41:10 AM
I  just braved the cold and the rain and went out to garage and loosened #1 drain screw and fuel ran out. Maybe tomorrow I'll check for spark. It was too cold to stay out there and, tonight I ran out of LP gas for heating so I may be in bed early.
That's disappointing and not, hope you've got the HT leads running to the right plugs, at least then it could be just a coil  :biggrin:

I didn't think it was that cold today, no sun about but not cold enough for heating yet.  :good:

1984 FJ1100
1979 Kawasaki Z1300
1972 Honda CB750/4 K2

Sparky84

Quote from: ribbert on April 17, 2021, 05:18:44 AM
It's about time you guys wised up and moved to Victoria  :biggrin:.

Down here in Autumn is the best place in the world, I spent 4 days last weekend in the High Country, just magnificent.

Noel

Any snow there yet?, it was a chilly weekend around last weekend, my hands were warmer while riding than sitting at the pie shop!  :lol:

Hope you're on the FJ and getting it ready for the rally  :good:
1984 FJ1100
1979 Kawasaki Z1300
1972 Honda CB750/4 K2

ribbert

Quote from: Sparky84 on April 17, 2021, 05:52:19 AM
Quote from: ribbert on April 17, 2021, 05:18:44 AM
It's about time you guys wised up and moved to Victoria  :biggrin:.

Down here in Autumn is the best place in the world, I spent 4 days last weekend in the High Country, just magnificent.

Noel

Any snow there yet?,

Not yet, still riding shorts, thongs and T-shirt. It's hit 30 C in the last week.

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"

Sparky84

Quote from: ribbert on April 17, 2021, 09:15:20 AM
Quote from: Sparky84 on April 17, 2021, 05:52:19 AM
Quote from: ribbert on April 17, 2021, 05:18:44 AM
It's about time you guys wised up and moved to Victoria  :biggrin:.

Down here in Autumn is the best place in the world, I spent 4 days last weekend in the High Country, just magnificent.

Noel

Any snow there yet?,

Not yet, still riding shorts, thongs and T-shirt. It's hit 30 C in the last week.

Noel
Yes we got that about a day or 2 after it past you, then it got a bit chilly, but at least we don't have to put our bikes in hibernation at all.
1984 FJ1100
1979 Kawasaki Z1300
1972 Honda CB750/4 K2

krusty

Quote from: Sparky84 on April 17, 2021, 05:45:30 AM
Quote from: krusty on April 17, 2021, 04:41:10 AM
I  just braved the cold and the rain and went out to garage and loosened #1 drain screw and fuel ran out. Maybe tomorrow I'll check for spark. It was too cold to stay out there and, tonight I ran out of LP gas for heating so I may be in bed early.
That's disappointing and not, hope you've got the HT leads running to the right plugs, at least then it could be just a coil  :biggrin:

I didn't think it was that cold today, no sun about but not cold enough for heating yet.  :good:


Haven't touched the plugs since the last time I rode it. Had a similar problem once with my CB750F1 - turned out to be plug caps.
Sun's out today. Had to cancel windsurfing yesterday due to lack of wind. Looks good for windsurfing today but I have a 2nd birthday party (a friend's granddaughter) to got to for lunch then dinner with friends  tonight.
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

krusty

Have been busy this last week getting acquainted with carbs. I have run three sets through a borrowed ultrasonic cleaner.
I'll call them set A, B, and C.
A set have come of my 1100 rider.
B set have come of 1100 under repair
C have come from a parts donor bike with locked motor, probably not run for may years.
ATM I'm having to decide which set to use for my rider. The set from C appear to be in the best condition, even before I soda blasted and ultrasonically cleaned them.
I've checked the jets installed and all are stock except for C which has 117.5 mains instead of 112.5. I think I will go with set C. All 3 bikes are fitted with the same "Pipeline" 4 - 1 exhaust system. Today I ordered a set of RPM pod filters which will make future carb swaps much easier. I am also waiting for carb kits as I need to replace pilot O rings and I also lost one of the tiny washers that go over the o ring.
A question I have is re pilot jet setting. I believe US versions are capped but not so for Oz models. In the past I have usually set the pilots by ear. The manual says they should be set using an exhaust gas analyzer which we all have in or shop - not. So the question, is there a guide somewhere in this forum site for doing this? BTW. When I stripped the carbs I checked the settings and A was all 2 turns out, B was all 1.5 turns and C was all over the shop between 3/4 and 2.
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

FJ_Hooligan

Set the mixture screws using the "Blip the Throttle" method.

Preset them to 2.5 turns out from lightly seated, or use the RPM method of scratching the tip of the mixture screw in the carb throat with your fingernail to preset them.

Now, blip the throttle (just a slight blip to 3K) and pay attention to how the RPM return to idle.
You'll see 1 of 3 possibilities.
RPMs will hang and slowly return to idle speed,
RPMs will quickly return to idle speed, but will undershoot before returning to desired idle speed,
Quick return to a stable idle with no hanging or undershoot is ideal.

Make 1/2 turns to see if the response gets better.  If it get better, keep adjusting in that direction until it gets worse then backup 1/2 turn

If the response immediately gets worse with the first 1/2 turn, then go the other way.
DavidR.

krusty

Quote from: FJ_Hooligan on April 29, 2021, 10:12:56 AM
Set the mixture screws using the "Blip the Throttle" method.

Preset them to 2.5 turns out from lightly seated, or use the RPM method of scratching the tip of the mixture screw in the carb throat with your fingernail to preset them.

Now, blip the throttle (just a slight blip to 3K) and pay attention to how the RPM return to idle.
You'll see 1 of 3 possibilities.
RPMs will hang and slowly return to idle speed,
RPMs will quickly return to idle speed, but will undershoot before returning to desired idle speed,
Quick return to a stable idle with no hanging or undershoot is ideal.

Make 1/2 turns to see if the response gets better.  If it get better, keep adjusting in that direction until it gets worse then backup 1/2 turn

If the response immediately gets worse with the first 1/2 turn, then go the other way.
Thanks for the refresher course on setting the pilots. It was pretty much how I've done it in the past but better explained.
An update.
I have since cleaned 3 sets of carbs and refitted the originals after having replaced the pilot o rings, washers and springs with slightly bigger mains. Also fitted RPM pods. So much easier than refitting the airbox.
Took it for a 100 mile shake down run last week and, apart from stopping once to adjust the idle, all went sweet, apart from blowing the lights fuse again which was odd as it was the third time it's happened after visiting the same cafe (Jerry's at Kulnura) for coffee.
Also adjusted the front brake lever free play. Front brakes are great, better than my 1200 with blue spots. It has 88 forks with Koni progressive springs, blue spots, original 16" front wheel and early V-max rotors, a very straight forward upgrade.
Just need s a little fine tuning of rebound damping of the rear YSS shock.
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