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Carb Cleaning Question

Started by Warp84, August 27, 2025, 03:02:25 AM

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Warp84

I've been doing the Carb cleaning for my 84' FJ1100 in an ultrasonic cleaner at my friend's tiny shop. But after coming out of the cleaner, regardless of it being air dried or using shop air, there's white particulate residue all over the carbs. It rub's right off the carb's but I don't know why residue is showing up after the carbs are dried, straight after being cleaned. If anyone can lend some insights I'd greatly appreciate it.

Is it possibly I need to make sure my friend is running Distilled Water with the solution instead of regular water? (Hard water stains) I'm not sure which he's doing.
1984 Fj1100

Billy Bananahead

I would consider cleaning the carbs myself by hand. Those ultrasonic cleaners will never get the carbs thoroughly clean.
In all the years that i've been biking i've never had a set of carbs cleaned ultrasonically.

Motofun

The last carbs I cleaned I put about a gallon of Berryman's carb cleaner in the ultrasonic heated bath.  It worked a miracle!  Wasn't sure if it cloud catch fire so I did it outside.... :scratch_one-s_head:
'75 Honda CB400F
'85 Yamaha RZ350
'85 Yamaha FJ1100
'89 Yamaha FJ1200
'09 Yamaha 125 Zuma
'09 Kawasaki KZ110 (grand kids)
'13 Suzuki GSXR 750 (track)
'14 Yamaha FZ-09
'23 Yamaha Tenere 7
SOLD: CBX,RZ500,Ninja 650,CB400F,V45 Sabre,CB700SC,R1,GSXR1000R

Chainlube

I have been using an ultrasonic cleaner, heated to 50C with water and a small amount of Simple Green HD (not the green stuff... That is not good for aluminum) on mine and customer bikes for several years.  I never let aluminum parts stay in for over 5 min or they will stain (rinse immediately!).  All removed metal parts go in the ultrasonic cleaner.  No plastic or rubber parts allowed!  The rest of the carb bodies are cleaned in a solvent tank, sprayed with carb cleaner where needed, rinsed and blown through with compressed air.  Never, ever, ever allow carb cleaner to come into contact with any rubber parts or they will be damaged and swell up!  Verify every passage is clear prior to reassembly.  I have been a professional motorcycle mechanic for almost 40 years, and this is the best process I have found to date. 
Current:
1984 FJ 1100
2024 XSR 900
2015 V7 Racer
1978 KZ 200

MarioR

Quote from: Billy Bananahead on August 27, 2025, 05:01:16 AMI would consider cleaning the carbs myself by hand. Those ultrasonic cleaners will never get the carbs thoroughly clean.
In all the years that i've been biking i've never had a set of carbs cleaned ultrasonically.

Let's say you have pilot jet channel plugged , idle fine but doesn't go smooth to rpm. How would you clean such a small channel manually vs ultrasonic cleaner?
It does not matter how slowly I go as long as I do not stop.

Pat Conlon

The way we used to do it before ultrasound.

Carb Soak and compressed air with a needle tip.  (Wear safety glasses)
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

FJmonkey

Quote from: MarioR on September 10, 2025, 08:01:05 PMLet's say you have pilot jet channel plugged , idle fine but doesn't go smooth to rpm. How would you clean such a small channel manually vs ultrasonic cleaner?

When you say idles fine, do you mean while on the choke? Or does it idle fine warmed up and off choke? Very important difference...

I would fix this by (cleaning them as discussed with a proper sonic soak) or replacing them for new ones, jets or carbs.  You could use some carb cleaner and copper/brass wire strands. But this rabbit hole is just as busy and labor intensive as the proper way. And you might not get it all for the effort. If you really have no options, break out the toothpicks and carb spray, and pray for the best. RPM can do a proper refresh on your carbs. Once the carbs are clean, keep them clean by running the bike frequently (every 2 weeks seems to work for me) to flush the Ethanol fuel from causing the plaque. Or drain the carbs after each ride, or use on-ethanol fuel. The ethanol is Bain :wacko2:  to our Kookaloo...
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

Billy Bananahead

Quote from: MarioR on September 10, 2025, 08:01:05 PM
Quote from: Billy Bananahead on August 27, 2025, 05:01:16 AMI would consider cleaning the carbs myself by hand. Those ultrasonic cleaners will never get the carbs thoroughly clean.
In all the years that i've been biking i've never had a set of carbs cleaned ultrasonically.

Let's say you have pilot jet channel plugged , idle fine but doesn't go smooth to rpm. How would you clean such a small channel manually vs ultrasonic cleaner?

As the others have said plus i'd fire loads of cleaning agents down the orifice's such as carb cleaner, brake cleaner, electrical contact cleaner, petrol, anything that is going to shift the caked on sh!te, then put the carbs back on and fire it up. Yes i know certain agents can damage rubber seals and o rings but if i can get away with it then that's great.  :diablo:

MarioR

Quote from: FJmonkey on September 10, 2025, 10:13:44 PM
Quote from: MarioR on September 10, 2025, 08:01:05 PMLet's say you have pilot jet channel plugged , idle fine but doesn't go smooth to rpm. How would you clean such a small channel manually vs ultrasonic cleaner?

When you say idles fine, do you mean while on the choke? Or does it idle fine warmed up and off choke? Very important difference...

I would fix this by (cleaning them as discussed with a proper sonic soak) or replacing them for new ones, jets or carbs.  You could use some carb cleaner and copper/brass wire strands. But this rabbit hole is just as busy and labor intensive as the proper way. And you might not get it all for the effort. If you really have no options, break out the toothpicks and carb spray, and pray for the best. RPM can do a proper refresh on your carbs. Once the carbs are clean, keep them clean by running the bike frequently (every 2 weeks seems to work for me) to flush the Ethanol fuel from causing the plaque. Or drain the carbs after each ride, or use on-ethanol fuel. The ethanol is Bain :wacko2:  to our Kookaloo...

This was only example  :biggrin:

Goint to the topic, no choke, idle fine, hesitate to go from idle to mid range, after mid is going fine...
It does not matter how slowly I go as long as I do not stop.

Chainlube

Quote from: MarioR on September 11, 2025, 02:35:24 PM
Quote from: FJmonkey on September 10, 2025, 10:13:44 PM
Quote from: MarioR on September 10, 2025, 08:01:05 PMLet's say you have pilot jet channel plugged , idle fine but doesn't go smooth to rpm. How would you clean such a small channel manually vs ultrasonic cleaner?

When you say idles fine, do you mean while on the choke? Or does it idle fine warmed up and off choke? Very important difference...

I would fix this by (cleaning them as discussed with a proper sonic soak) or replacing them for new ones, jets or carbs.  You could use some carb cleaner and copper/brass wire strands. But this rabbit hole is just as busy and labor intensive as the proper way. And you might not get it all for the effort. If you really have no options, break out the toothpicks and carb spray, and pray for the best. RPM can do a proper refresh on your carbs. Once the carbs are clean, keep them clean by running the bike frequently (every 2 weeks seems to work for me) to flush the Ethanol fuel from causing the plaque. Or drain the carbs after each ride, or use on-ethanol fuel. The ethanol is Bain :wacko2:  to our Kookaloo...

This was only example  :biggrin:

Goint to the topic, no choke, idle fine, hesitate to go from idle to mid range, after mid is going fine...

That could mean a slide diaphragm issue, slide needle issue, mixture screw issue or simply the carbs could be out of sync.
Current:
1984 FJ 1100
2024 XSR 900
2015 V7 Racer
1978 KZ 200

MarioR

Quote from: Chainlube on September 12, 2025, 12:02:39 PM
Quote from: MarioR on September 11, 2025, 02:35:24 PM
Quote from: FJmonkey on September 10, 2025, 10:13:44 PM
Quote from: MarioR on September 10, 2025, 08:01:05 PMLet's say you have pilot jet channel plugged , idle fine but doesn't go smooth to rpm. How would you clean such a small channel manually vs ultrasonic cleaner?

When you say idles fine, do you mean while on the choke? Or does it idle fine warmed up and off choke? Very important difference...

I would fix this by (cleaning them as discussed with a proper sonic soak) or replacing them for new ones, jets or carbs.  You could use some carb cleaner and copper/brass wire strands. But this rabbit hole is just as busy and labor intensive as the proper way. And you might not get it all for the effort. If you really have no options, break out the toothpicks and carb spray, and pray for the best. RPM can do a proper refresh on your carbs. Once the carbs are clean, keep them clean by running the bike frequently (every 2 weeks seems to work for me) to flush the Ethanol fuel from causing the plaque. Or drain the carbs after each ride, or use on-ethanol fuel. The ethanol is Bain :wacko2:  to our Kookaloo...

This was only example  :biggrin:

Goint to the topic, no choke, idle fine, hesitate to go from idle to mid range, after mid is going fine...

That could mean a slide diaphragm issue, slide needle issue, mixture screw issue or simply the carbs could be out of sync.

Diagrams are good, Slide needle set up - may need to go up, mixture screw set up good and carbs synchronized.
It does not matter how slowly I go as long as I do not stop.

Warp84

I figured I should give a follow up to the going's on with my stack. I tore down the BS36 stack down to just the housings again and hit all the jets and bodies with a bunch more carb cleaner then straight to blow dry with shop air. While doing this round of cleaning I found out the main jets were the wrong size. They were 42.5 Main's instead of 37.5's. So I purchased new main's from RPM. All other jets were correct according to the Clymer Shop manual I have. After re-assembly we test fired the bike with Ethanol free fuel. Now the bike fires on all 4 cylinders at idle. (Before #3 was dead at idle and only came alive under power) Synch is within 1 point of each other on the entire stack using a digital man-o-meter. Idle's high at 1300 rpm and hangs at 2k rpm. Working on tuning those other issues out atm.
1984 Fj1100

Pat Conlon

You are describing pilot jets not main jets.
Who told you #42.5 pilots were wrong?
 US market FJ's were jetted lean from the factory. Other non USA FJ's had #42.5 pilots installed in the factory.
Lean #37.5 pilots run hotter.

After cleaning be sure to replace all your o rings, especially the o rings on your float needle seats.
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

Warp84

Quote from: Pat Conlon on September 23, 2025, 12:48:45 PMYou are describing pilot jets not main jets.
Who told you #42.5 pilots were wrong?
 US market FJ's were jetted lean from the factory. Other non USA FJ's had #42.5 pilots installed in the factory.
Lean #37.5 pilots run hotter.

After cleaning be sure to replace all your o rings, especially the o rings on your float needle seats.
I was going by the Clymer shop manual I have. Which marks 42.5 pilot's for the 1200 but 37.5 for the 1100. All the o-rings and gaskets were already refreshed.
1984 Fj1100