2005 600F Great Idle! Wont throttle :(

[batman]

When I just barely touch the throttle, it revs up from its normal idle of 1200 rpms to 4000 rpms. If roll on the throttle, the bike stalls. I made sure I gave it plenty of time to warm up, and I tested it for vacuum leaks but found none.


A few weeks ago I found 2 of the carbs and the petcock dripping into a puddle of fuel under the bike. It turned out the petcock vacuum was malfunctioning and ruined those two float needles which leaked gas through the cylinder and eventually into the oil and overfilled my oil.

I have since cleaned the carbs, replaced O-rings and float needles in all 4 carbs, replaced the petcock, changed the oil, sync'd the carbs, and replaced the spark plugs. I also did a compression test just to be sure and they are all within specs.

I know it's not the petcock because the bike does the same thing with an aux tank on.




UPDATE: I changed the spark plugs. Opened up all 4 carb bowls and blew compressed air into all the jets. I took out each pilot jet and they all look good. I adjusted the pilot screws back to 2.5 turns out.

I actually got to ride the bike! First time in weeks! The bike doesn't stall now, but at about half throttle it bogs down to low rpms.

Suggestions?

[Kreylyn]

When I just barely touch the throttle, it revs up from its normal idle of 1200 rpms to 4000 rpms. If roll on the throttle, the bike stalls. I made sure I gave it plenty of time to warm up, and I tested it for vacuum leaks but found none.


A few weeks ago I found 2 of the carbs and the petcock dripping into a puddle of fuel under the bike. It turned out the petcock vacuum was malfunctioning and ruined those two float needles which leaked gas through the cylinder and eventually into the oil and overfilled my oil.

I have since cleaned the carbs, replaced O-rings and float needles in all 4 carbs, replaced the petcock, changed the oil, and sync'd the carbs. I also did a compression test just to be sure and they are all within specs.

I know it's not the petcock because the bike does the same thing with an aux tank on.

Throttle adds air. More air draws more fuel as it passes through.

If your quick on the throttle and that kills the bike, generally your looking at too much air and not enough fuel. Something is leaning it out.

I would double check your sync... that's very common matching issue/symptom. Also confirm your a/f settings and float heights.

Krey

[batman]

Throttle adds air. More air draws more fuel as it passes through.

If your quick on the throttle and that kills the bike, generally your looking at too much air and not enough fuel. Something is leaning it out.

I would double check your sync... that's very common matching issue/symptom. Also confirm your a/f settings and float heights.

Krey

Float heights are good. They have been double and triple checked. I double checked the sync this morning. What is a/f settings? Air/Fuel? I thought I was doing that correctly. I turned the a/f mixture screws until I felt some resistance, then I turned them 2.5 times backwards, or out.

Also its not about being quick on the throttle, give it throttle slow or quickly and the bike dies.

[Kreylyn]

Float heights are good. They have been double and triple checked. I double checked the sync this morning. What is a/f settings? Air/Fuel? I thought I was doing that correctly. I turned the a/f mixture screws until I felt some resistance, then I turned them 2.5 times backwards, or out.

Also its not about being quick on the throttle, give it throttle slow or quickly and the bike dies.

Your not getting enough fuel from the carbs some how. Either there is a limit to fuel into the carbs (low fuel flow), the air box is off or the airbox drain line is not connected (improper back pressure air box side), missing a vacuum port being blocked off somewhere or some other massive air leak (vacuum/air leak), or the carbs are dirty and need to be cleaned better (passages in the carbs preventing enough fuel to flow...).

Krey

[kevin2502000]

Bad plugs will also do this. If you ran it with fuel laden oil, you need fresh plugs. You're sure you fixed that problem?

[batman]

Bad plugs will also do this. If you ran it with fuel laden oil, you need fresh plugs. You're sure you fixed that problem?

I will take them back out and sand them again. They are new plugs. I have not rode the bike with these plugs. I have tried to start and idle the bike with them, so yes they have been exposed to some oil, but they should be working or I'm going to be pissed. I spent over $60 on these iridium plugs.


NOTE: I checked the pilot screws, no effect.

[badwithcomputer]

go with the CR9E skip all that fancy stuff. They are 6 bucks a plug, I switched last year after having to replace plugs twice due to fouling, then when i finally got things sorted out with my carbs I switched to those and haven't noticed a difference. Replace the plugs.

[Kreylyn]

NOTE: I checked the pilot screws, no effect.

Please describe in more detail what you mean by this. You changed the a/f settings and there was no effect on how the engine ran at all?

Krey

[batman]

go with the CR9E skip all that fancy stuff. They are 6 bucks a plug, I switched last year after having to replace plugs twice due to fouling, then when i finally got things sorted out with my carbs I switched to those and haven't noticed a difference. Replace the plugs.

Sounds good, I'll try that next weekend when it's not raining. Thanks.

Please describe in more detail what you mean by this. You changed the a/f settings and there was no effect on how the engine ran at all?

Krey

Yes. I had my BikeMaster carb sync tool hooked up to the bike while I adjusted a pilot screw. I did not notice a change in the vacuum or the revs while I turned the pilot screw in or out. No change.

I could only reach one of them with a small screwdriver though since that fucking $20 motion pro piece of shit adjustment tool doesnt fucking work.

I thought maybe I couldn't hear a difference because I could only adjust one out of four carbs (the other side still has plastics on).

I do have the carbs removed and I'm about to disassemble and clean them again just to be sure.

[Kreylyn]

Yes. I had my BikeMaster carb sync tool hooked up to the bike while I adjusted a pilot screw. I did not notice a change in the vacuum or the revs while I turned the pilot screw in or out. No change.

I could only reach one of them with a small screwdriver though since that fucking $20 motion pro piece of shit adjustment tool doesnt fucking work.

I thought maybe I couldn't hear a difference because I could only adjust one out of four carbs (the other side still has plastics on).

I do have the carbs removed and I'm about to disassemble and clean them again just to be sure.

This could point towards the pilot jet system not being clean enough. There should have been a change when adjusting the a/f screws. Generally speaking, if turning them out does not change things... there is a clog in the system.

Krey

[batman]

This could point towards the pilot jet system not being clean enough. There should have been a change when adjusting the a/f screws. Generally speaking, if turning them out does not change things... there is a clog in the system.

Krey

Yeah. I was thinking that because I ran the fuel laden with oil through the carbs AFTER I had cleaned the carbs, that maybe they got clogged. So I will be going through the carbs again.

[batman]

UPDATE: I changed the spark plugs. Opened up all 4 carb bowls and blew compressed air into all the jets. I took out each pilot jet and they all look good. I adjusted the pilot screws back to 2.5 turns out.

I actually got to ride the bike! First time in weeks! The bike doesn't stall now, but at about half throttle it bogs down to low rpms.

Suggestions?

[kevin2502000]

Click my sig link

What do your plugs look like?

[batman]

Click my sig link

What do your plugs look like?

What do you mean? I went and bought some brand new ones today. They're brand new.