Bandit 600 with gsx750f engine

[K7svy]

Hello. I recently brought a gsx 750 f 1998
I decided to swap the engine/carbs into my b6 bandit 
 The engine ran good when it was in the gsx frame didn’t idle high. but I’m now having an issue with the idle sitting way to high.

engine runs fine pulls nice it’s just high idle at 3k

things I’ve checked

Used carb cleaner to see if there is any air leaks I cannot find any

checked throttle cables got plenty of slack

idle screw is all the way out

checked choke mechanism 

 

Anyone have a idea what else to look for?

[DAZ]

Hello and welcome

Have you checked the actual throttle linkage (not just the cable) has not got knocked and that the butterflies and slides are closing properly, it's possible that something is askew after being removed and refitted especially if they were being a bit stubborn or the rubbers were stiff and a bit of brute force was required.... 

Edited August 5 by DAZ
Addition

[K7svy]

1 hour ago, DAZ said:

Hello and welcome

Have you checked the actual throttle linkage (not just the cable) has not got knocked and that the butterflies and slides are closing properly, it's possible that something is askew after being removed and refitted especially if they were being a bit stubborn or the rubbers were stiff and a bit of brute force was required.... 

I’m planning on stripping it down later on I shall check this while I’m there! Cheers

[wraith]

Welcome to OSS 

With engine off (not running) open the throttle and then let if go, you should hear the carbs/throttle snap shut. If you don't the carbs are not shutting fully.

[Dezza]

Has the throttle cable adjuster got a locknut under the cable mount? If so and it's not been done up properly, the nut can drop down the cable and prevent the throttle shutting fully causing the symptoms you describe.

[K7svy]

So I have sorted this now. The person who said he would change the float bowl gaskets decided to mess with the butterfly valve screws… ( he’s not touching my bike again) cheers all for the suggestions 

[DAZ]

?

[Dezza]

7 hours ago, K7svy said:

So I have sorted this now. The person who said he would change the float bowl gaskets decided to mess with the butterfly valve screws… ( he’s not touching my bike again) cheers all for the suggestions 

Elaborate: how did faffing with the butterfly screws (which are very difficult to remove) affect the idle speed?

[Dezza]

Edited August 6 by Dezza
Posted in worng thread: doh!

[K7svy]

Sorry I should have. Wrote this better. My bad it was late

so as I was looking at the carbs the 2 of the butterfly valves was slightly open the other too was closed I ended up adjusting the valves so they all matched up.

I’ve attached a picture of the screws I adjusted 

I believe the screws are for carb balancing? 

[Dezza]

OK, I understand now. I thought before you meant the two screws that hold each butterfly valve to the rotating shaft not the balance screws. If the carb bank had been split then yes these could have come out of adjustment and held one or more butterfly open. When the carbs are off you could do a bench balance before refitting, making sure each butterfly is open an equal amount in synch. This is done using a bit of thin wire and adjusting the balance screws and idle adjuster.

[K7svy]

On 8/6/2024 at 4:19 PM, Dezza said:

OK, I understand now. I thought before you meant the two screws that hold each butterfly valve to the rotating shaft not the balance screws. If the carb bank had been split then yes these could have come out of adjustment and held one or more butterfly open. When the carbs are off you could do a bench balance before refitting, making sure each butterfly is open an equal amount in synch. This is done using a bit of thin wire and adjusting the balance screws and idle adjuster.

Yeah I done it by eye then later on done it with a carb sync tool and it was spot on the bike runs absolutely beautiful now. The swap was definitely worth it made the blandit less bland