83 xj750 has spark, gets fuel to the carbs turns over stron, wont even try to start

Bike was barely running, took carbs apart. Two floats were stuck. Put new floats in and new float valve needles. Put it back together. i know its getting fuel because i opened the bowls and fuel came out. Getting spark with new plugs. All it does is turn over, and over, and over. No backfire no nothing. Please help! I had a lot of plans for this bike, took it all the way down to the frame, cleaned it all up, sanded and primered the tank, put new Z-Bars on for handlebars, new mirrors, springer seat, still alot to do but would like to get it running before i go any further.

 

Try pulling your plugs and add a teaspoon of gas in each cylinder, reinstall the plugs and turn it over to see if it fires. You may have gas in the carbs but none going to the cylinder. This will at least see if it fire.

 

I'll give that a try,thanks

 

Gave that a try and still nothing.

 

have you checked the compression?

FU

 

Not yet

 

If i took the air box out and put individual pods on and left the mufflers off, could that be causing my problem

 

not really, it should still fire up and run.

FU

 

did you do a bench sync and wet set the floats before putting them back on the bike?

FU

 

the compression numbers are as follows;

156psi @ 300rpm

FU

 

are the plugs wet? Pull a plug put it in the cap grounded put your finger over the spark plug hole turn it over when your finger gets blown off it should spark at the same time. Your carb boots did not split when you R&R the carbs. Sounds very strange if you put gas in the cyl and have spark it should crank backfire or something.

 

Seems to me if you had good spark you would have some type of combustion, backfire or fart. I'd look in the electrical area, How's the timing, coils and especially battery

 

I did bench sync the carbs, don't know how to wet set

 

No the boots didn't splitwas planning to replace them anyway, however would like to get some response out of her first.

 

http://www.xj4ever.com/setting fuel levels.pdf

How did you test for spark? obviously if the float levels are not set right it will not run properly. If you can, get the airbox back in and do not fiddle with pods until you get it running with the stock setting, otherwise you will be chasing your tail and will never run properly

 

I will do whatever i have to do to get it running, i may have to buy a new air box. I didn't think it would be a problem since it was running before, just not running good due to the floats that were stuck.

 

floats have to be to low it will run without an airbox. Put your hand over 1 or 2 carbs and give it a crank if its fuel related it will pop or something. Also make sure your cable did not slip on the carbs where its secured. I started my 750 maxim without an airbox a few weeks back

 

It starts now, i had the coils plugged in backwards making out out of time. Now if i give it any gas out dies

 

Have you done any of the carb work that has already been mentioned?

 

I put new floats in, and got them level. I know i will have to put stage 3jets in because i went to individual pods and running straight pipes. But i thought it should run, maybe run rich until i change the jets. Am i wrong?

 

Maybe overly rich. Pull a plug and tell us what it looks like.

Gary H.

 

Did you clean all of the air and fuel passages thoroughly?
Did you inspect the diaphrams for small holes or tears?
Did you remove the emulsion tube and clean it?
Did you binch synch the carb butterfly valves?
Did you clean and polish the slides and the slide bores?
How did you set the float level?
Did you confirm the correct fuel level using a length of clear tubing as a sight glass?
And since the carbs are on the bike; did you use propane or carb cleaner to check for vacuum leaks?
Did you remove any of the air jets, and if you did were they put back in the right place (the manual has a misprint)?

Switching to pods and straight pipes will cause the mixture to be lean, not rich.
Do the pods you are using have any length to them, or do they sit right on the intake throats? CV carbs require smooth airflow to operate properly. You can use the carb-to-aribox boots as intake runners to see if that helps.

 

K-moe, I'm referring to this.

Gary H.

 

http://www.xj4ever.com/setting fuel levels.pdf

 

These plugs were brand new and the bike has only ran for a matter of seconds

 

+1.

Gary H.

 

Unfortunately, i will have o wait until the weekend to pull the carbs back off. I'll be resetting the carbs again over the weekend, thanks

 

Can you tell anything i should be looking for by looking at the pic of the plug?

 

Looking at one plug that has only run at idle isn't going to tell any of us anything about fueling. You've got to get the carbs to the point that you can take it above idle. All that plug shows is the richness that is left from startup.