Tryin to go, not getting enough fuel?

Quick question, I was having a high rev problem on my 85xj700. Found this to be a hose clamp catching the throttle linkage and holding it open barely. It was reving to 8000 rpm's on start up and I would kill it, now that the problem has been rectified it idles nice at 1000 rpm's but when give it throttle now it wants to cut out and when it manages to reach 5000 rpm and i let off the throttle it takes 3-5 sec before it comes back down to idle. Everthing sounds beautiful and I just did a total carb rebuild just cant figure out how to get the throttle response better. Also are there any recommendations on what to use to coat the inside of the gas tank? Gonna be a winter job, just tryin for the info! Thanks for all the help, you guys are great!

 

when it does idle at 1k is the choke on or off?
if choke on, how does it run with choke off?
is your air box in tack and properly attached to all 4 carbs?
what does a complete rebuild of the carbs consist of?
is the air filter properly installed (no leaking past it)?
is the vac hose from your #2 cylinder intake attached to the petcock and is the hose known good?

i don't really have any good ideas but it may help if some of these q's were answered.

 

Well it idles at 1k with the choke off, and the airbox boots where a pain in my a$$ so I know they are on good.....haha fought with them to make sure. When I did the carb clean/rebuild I just mean new needle & seat, gaskets, o-rings, and all new jets. Checked and floats were all ok, did not do anything with the diaphrams. I'm extremely new at all this and it took about two weeks to clean and change these things without help except the instructions on this site. Oh, and preformed a bench sync while I had them off. I have not done anything with the air filter itself so I will check that out but I noticed a small amount of fuel on top of the carb body tonight and it appears somehow my inline fuel filter is cracked. I got a new one from napa and with put it on tomorrow. As far as the vacuum line from the petcock it appears to the eye in good condition, is there a way to check properly? Thanx again for any help.......hittin the sack for now!

 

vauum lines need to be tight. not just look good.

how did you clean the carbs? were they bad enough to warrant new jets? if so. then the passages might still be plugged.

how's your float level. do you have 3mm fuel level on the carbs. sounds like the carbs aren't geting enough gas.

 

Brother, ...
You got some work to do.

But, before we even suggest what you should do first; let's see what you've done ... so far!

Did you remove and clean the Emulsion Tubes (Nozzles)?
Did you refinish the Diaphragm Piston Bores?
Did you flush-out all the Jets and Passages?
Did you Bench Sync the Carbs prior to reinstalling them?
What other Tuning did you do?

 

Okay, I replaced all the jets because it looked like the p/o tried to get them off and broke the top of all the jets so I had to use a pliers to remove them. I did spray compressed air and carb cleaner through them before I insalled all new jets. I did not do anything under the top hats because I dont really know much about the carbs so I was taking it slow. I did a bench synch using the instruction of a previos post with 3x5 card. As far as tuning other than that ive done nothing never anything else. What are the emulsion tubes? overflows? This is i believe the hitachi carbs just throwin that out there! thanks for the insight.

 

The Emulsion Tube ... (Or 'Nozzle') ... is the Center Tube that the Main FUEL Jet Screws into.
To remove it you have to Remove the Main Fuel Jet and Washer, ...
Then, ... Remove the Carb Top, Spring and Diaphragm, ... and Drive-out the Center Tube through the Top of the Carb.

The Center Emulsion Tube is Hour-glass shaped and contains 15 -to- 20 AIR Jets that Regulate Main AIR's entrance to the Intake Stream, ... BOTH carrying and atomizing the Fuel Flow.

IF, ... The Emulsion Tubes are not Cleaned ... Performance, ... particularly High-Speed performance will be most adversely affected.

 

ok, i sprayed cleaner through them and compressed air but did not remove them. But when I had the problem of the butterflys hanging open because of the clamp on the intake boots it was red lining at start up instantly, now that I have the clamp i the right position i cant get it past 4k with it at full throttle. Also, when I first hit the throttle it bogs down a little then a slow climb to the 4k and if I hold it there after 2-3 sec it goes down to 1k and slowly begins to climb back up. Seems like its not getting enough fuel where as before it was getting way to much. I really dont get it.

 

Should I pull the carbs again and clean the emulsion tubes or is there a few other things that can effect this that I could check first without having to pull the carbs back off?

 

Yep, ...

Clean the Emulsion Tubes!


Refinish the Diaphragm Piston Bores:
Remove oxidation and Polish for performance:


Search: "Clunk Test"

 

+1 on RickCoMatic's comment, gotta pull those babies. These carbs are not the type where a "quicky" job will do. Gotta go through everything to make sure that all is clean (not just looks clean, but CLEAN) because if you solve a few obvious things, and leave issues, tuning is going to be a neverending process.

Other thoughts could be air leak. You could always spray some hot shot around all the carb holders to see if you get a rise in the RPMs. If you do then, ho got an air leak, but honestly this sounds like a fuel issue.

good luck

Kevin

 

A fouled Emulsion Tube (Nozzle) will rob any chance of getting the Bike to perform well.

There's NO way to Clean them without removing them.