Clarified Pilot screw Adjustment Procedure

[Mooskee]

Clarified Pilot screw Adjustment Procedure

I AM NOT RESPONSIBLE FOR ANY DAMAGE OR INJURY TO YOU OR YOUR BIKE.
USE THIS INFORMATION AT YOUR OWN RISK!

NOTES:

• •   I did a lot of research to clarify exactly how to make the carb pilot screw adjustments. The info is scattered about the forum, but I wanted to put it together in one place so here ya go.
  •   I posted a question on the forum and was unable to get clarification, so this is my opinion based on what I believe makes sense of the Honda Manual for making the adjustment.
  •   The pilot screws are factory pre-set and no adjustment is necessary unless the pilot screws are
  replaced.
  •   I had a backfire problem which led me to rebuild the carbs and replaced the pilot screws.
  •   I found a bad air cut off valve. Thank you, Redeye, for the great test tools included in your carb kit.
  •   After rebuilding and adjustment, I have no backfire problem.
  •   Used my Digi Sync for the tach.
  •   Carbs were synchronized prior to adjusting pilot screws as stated in manual.
  •   The bike was level on a jack stand.
  •   A fan was blowing on the radiator. That way hot air is blowing on me so I can pretend I am riding across Death Valley. However, I soon realized Death Valley is not this hot.
  •   I noted a drop of about 30 rpm every time the bike fan came on, so I waited about 1 minute for it to go off to adjust pilot screws. That way I get to work on the miserably hot motor even longer.
  •   The Honda carb adjusting tool is expensive, and I am unable to make the adjustments with a stubby tool. My hands do not fit in there and the blisters on my fingers take too long to heal.
  •   I found several tools on the market. Some of them had reviews that the gears are cast and rough, and that you can't feel what you are doing. Some have flexible shafts inside making them inaccurate.
  
• •   I found the Pit-Posse-Motorcycle-Carburetor-Adjusting/dp/B004N0EX7Y. It has an enclosed 90-degree head with 7 different attachments. The gears are machined and smooth. It is about 19 inches long and will adjust the pilot screws quite effectively. It is my second favorite Valkyrie tool. The Digi Sync is my favorite.

https://www.amazon.com/Pit-Posse-Motorcycle-Carburetor-Adjusting/dp/B004N0EX7Y/ref=pd_lpo_263_t_1/131-7854696-0314364?_encoding=UTF8&pd_rd_i=B004N0EX7Y&pd_rd_r=fd03fb6d-62b1-4f06-9e75-9b2e3ae52be4&pd_rd_w=vPKti&pd_rd_wg=THjev&pf_rd_p=7b36d496-f366-4631-94d3-61b87b52511b&pf_rd_r=JMG5E4TK07X76N8E7WPM&psc=1&refRID=JMG5E4TK07X76N8E7WPM


THE CLARIFIED PROCEDURE
1.Turn the pilot screw clockwise until it seats lightly, then
back it out to the specification given. This is an initial setting prior to the final pilot screw adjustment.

INITIAL OPENING: (base setting)
'97 GL1500C/CT:
Except California type: 1 -3/4 turns out
California type: 2 turns out
GL1500CF. After '97 GL15OOC/CT:
Except California type: 2-1/4 turns out
California type: 2-3/8 turns out

2. Warm up the engine to operating temperature. Stop and go driving for 10 minutes is sufficient.
3. Stop the engine and connect a tachometer according to the tachometer manufacturer's instructions.
4. Start the engine and adjust the idle speed with the throttle stop screw.

IDLE SPEED: 900+100 rpm

5. Turn #1 pilot screw 1/2 turn out from the initial setting.
a. If no increase in rpms is detected turn it back in to the base setting.
b. If the engine speed increases by 50 rpm or more, turn pilot screw out again 1/2 turn.
c. If no increase of rpms is detected then, turn that screw back in 1/2 turn.

6. Adjust the idle speed with the throttle stop screw.
7. REPEAT steps 5 through 6 for the # 2, 3, 4, 5 and 6 carburetor pilot screws.

8.Turn the No.1 carburetor pilot screw in until the engine speed drops by 50 RPM
9.Turn the No.1 carburetor pilot screw out one full turn from the position obtained in step 8.
10. Adjust the idle speed with the throttle stop screw.

11.Perforrn steps 8, 9 and 10 for the # 2, 3, 4, 5 and 6 carburetor pilot screws


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[yrunvs]

After going through the procedure I'd be very interested to know the difference between your base opening screw settings and your final opening screw settings?

[Mooskee]

After going through the procedure I'd be very interested to know the difference between your base opening screw settings and your final opening screw settings?

My base is 2 1/4 turns out (1998 Tourer - NON California). My final opening screw settings are 1 1/2 + 1/8 from one carb to the next.

When going out at the beginning of the procedure, I had rpm changes less than 50 rpm, so they were returned to the base setting on all six pilot screws.

[..]

Thanks.

Saved to my Valkyrie folder.

[yrunvs]

I would have guessed 2 to 2.5 turns out.....that's interesting thank you.

[Mooskee]

I would have guessed 2 to 2.5 turns out.....that's interesting thank you.

I agree. That is what I expected too. I'm sure I could have run it another 20 years without adjusting it at all! I am particular about calibration. It is an ingrained flaw in my character  . I was a tech in the Navy and then spent 23 years as a tech in nuclear power. I followed that by teaching nuclear power techs how to calibrate and maintain nuclear control systems. I just can't leave it unadjusted . After going through the procedure  my final opening screw settings ended up 1 1/2 + 1/8. It messed with my head so much I called for a repeat and rechecked. Maybe it can vary from bike to bike, although I am not sure how to justify that.

[The emperor has no clothes]

I would have guessed 2 to 2.5 turns out.....that's interesting thank you.

I agree. That is what I expected too. I'm sure I could have run it another 20 years without adjusting it at all! I am particular about calibration. It is an ingrained flaw in my character  . I was a tech in the Navy and then spent 23 years as a tech in nuclear power. I followed that by teaching nuclear power techs how to calibrate and maintain nuclear control systems. I just can't leave it unadjusted . After going through the procedure  my final opening screw settings ended up 1 1/2 + 1/8. It messed with my head so much I called for a repeat and rechecked. Maybe it can vary from bike to bike, although I am not sure how to justify that.

Wouldn't altitudes and temps have some bearing ? Can you notice any hint of leanness when riding it ?

[John Schmidt]

While they're out of the bike, I just set all six to 2 turns out and forget about it. After installation, I sync the carbs and I'm good. Plugs look good so I leave it alone at that point. I get good mileage and performance, that's all I need or want.

[Mooskee]

Wouldn't altitudes and temps have some bearing ? Can you notice any hint of leanness when riding it ?

Altitude makes a difference. I live at sea level, but the Honda manual tells you to adjust the pilot screws first. Then in the next section it addresses high altitude adjustment for continuously riding above 6,500 feet. I live at 20 feet above sea level.

HIGH ALTITUDE ADJUSTMENT
When the vehicle is to be operated continuously above 2,000
m (6,500 feet), the carburetors must be readjusted as described below to improve driveability and decrease exhaust emissions.

Warm up the engine to operating temperature. Stop and go driving for 10 minutes is sufficient.
Turn each pilot screw in to the specification given.

TOOL:
Pilot screw wrench. D 07KMA-MN90101 or
07MMA-MV9010A
{U.S.A. only)

HIGH ALTITUDE SETTING: 1/2 turn in
Adjust the idle speed with the throttle stop screw.

IDLE SPEED: 90Dk100 rpm

NOTE
This adjustment must be made at high altitude to ensure proper high altitude operation.

You also asked

Can you notice any hint of leanness when riding it ?

Nope. Runs like a scalded dog. I'll check plugs after some miles, but I have no backfiring and it is running well and it is adjusted per the factory manual. I'm good to go.

[Mooskee]

Thanks.

Saved to my Valkyrie folder.

Britman, you are welcome. I hope it helps.