Non Venture question

[stickhandle2]

Hi Folks,

 

I am reaching out to you in hopes someone can give me a hint. I am working on an 84 XJ750RL, sweet bike I bought off a friend of my daughters last summer, when I got the bike it was tough to start, hadn't been ridden in a few years so I pulled the carbs and gave them a cleaning.

 

I put the carbs back on, gave it a boost from car as bike battery is toast......the xj started right up, but it is idling between 4500 and 5000rpm.....turned idle screw all the way back.....still the same.....figure it has to be sucking air...put filter pods on carbs, still the same....ok figure boots may be leaking but when the carbs were off they looked solid no cracks....pulled carbs off and then pulled boots off to look closer at them....boots look ok, even the caps on the vacuum tubes on the boots look ok........this has me confused as the bike idled ok when I got it going a few times when I brought it home. Any hints!!!!

 

Thanks Mike

[CaseyJ955]

I have experienced high erratic idle with carbs way out of synch but 4500 is quite a reach. Throttle barrel and cables/linkage free, opens and snaps shut free and easy? Routing of throttle cable correct?

Choke linkage operating properly. Air filter clean? Slides open and slide shut again.

 

Not real fmiliar with that model, just trying to throw a bone from general experience until a real pro steps in.

[stickhandle2]

I have experienced high erratic idle with carbs way out of synch but 4500 is quite a reach. Throttle barrel and cables/linkage free, opens and snaps shut free and easy? Routing of throttle cable correct?

Choke linkage operating properly. Air filter clean? Slides open and slide shut again.

 

Not real fmiliar with that model, just trying to throw a bone from general experience until a real pro steps in.

 

Yes to all, which is why I am thinking vacuum leak somewhere. Walked away from it so I could clear my head......what better way to clear my head...go for a ride on the RSV. Thanks for your ideas.

 

Mike

[slowrollwv]

Make sure that the butterfly's in the carbs are free and working proper. My son had one bent in his Honda and it would run at those RPMs.

[MiCarl]

The XJ carburetors have a little link that the throttle cable attaches to. That link needs to be pointing up when the carburetors are installed into the boots - otherwise it catches on the head and holds the throttles open. The other thing that can happen on an XJ is the throttle cable doesn't drop down into the seat and that will hold the throttles open too.

[stickhandle2]

The XJ carburetors have a little link that the throttle cable attaches to. That link needs to be pointing up when the carburetors are installed into the boots - otherwise it catches on the head and holds the throttles open. The other thing that can happen on an XJ is the throttle cable doesn't drop down into the seat and that will hold the throttles open too.

 

Thank you I will check for that, when I had it running, even with the very high idle the throttle still worked, but I will check that again when I put the carbs back on the bike.

 

Mike

[stickhandle2]

Make sure that the butterfly's in the carbs are free and working proper. My son had one bent in his Honda and it would run at those RPMs.

 

Thank you, yes they are moving smoothly, thanks for the hint.

 

Mike

[MiCarl]

Some other things to look for:

 

When pilot jets get plugged up it's not unusual for an owner to crank up the idle so the thing draws some main fuel. Then when the carbs are cleaned the idle is really high and needs to be turned down. Not a problem unless:

 

1) Owner adjusted the idle with the cable adjuster - making the cable too short. Make sure you have some slack in the throttle cable.

2) Owner adjusted the idle by turning the sync screws. This should be caught by a visual inspection of the synchronization while the carbs are off the motorcycle.

[stickhandle2]

Some other things to look for:

 

When pilot jets get plugged up it's not unusual for an owner to crank up the idle so the thing draws some main fuel. Then when the carbs are cleaned the idle is really high and needs to be turned down. Not a problem unless:

 

1) Owner adjusted the idle with the cable adjuster - making the cable too short. Make sure you have some slack in the throttle cable.

2) Owner adjusted the idle by turning the sync screws. This should be caught by a visual inspection of the synchronization while the carbs are off the motorcycle.

 

Thanks, I think it was sucking in too much air, I went over everything I did and reinstalled the boots with new gaskets, then heated up the boots when I put the carbs on this just made it way easier. I heard the carbs slip into place and then made sure everything was nice and tight. Started right up at a good speed on the choke, turned down the choke and bike stalled .......ooops forgot when it was idling fast I had backed off the idle screw, (that was where I thought it must be sucking air), restarted the bike and turned up the idle screw, the bike now idles nice at around 1050rpm. Couple more things to do and then it will be ready for the road.

 

Thanks for all the suggestions and hints.

 

Mike