my xj 650 engine wont start just pops!!!

Just about has to be a stuck needle if one carb is empty and the others are full. You may be able to remove the bowl from #1 carb without taking the carb rack out of the bike. If you can remove the 4 screws from the float bowl at the bottom of the carbs you may be able to remove the float hinge pin, and the float assy

If the needle is stuck in the closed position against the needle seat then gas can't flow.

The needle being stuck in the closed position seems unlikely as one would expect the float to fall as the bowl empties due to evaporation etc.

If you try this check to make sure the little wire bail connected to the needle is attached to the tang on the float assy.

Best way? Remove carbs, clean them thoroughly and re-assemble. This will let you get a very good look at what is going on.

Loren

 

ok i took the carbs off and cleaned them it had green gas and silicone in it the wire bail. so i cleaned it all up and hooked up my air compressor to were the gas goes in and all the air compensator jets had air coming out except for carb 1 until i turn up the air then a little bit came out and all the others had air racing out fast. carb one has something stuck in the internal parts. i thing im going to by some carb cleaner today

 

OK. Read VERY CAREFULLY. You need to clean them properly. If carb 1 had bits of silicone in it then you have problems. Search the how to section and it will tell you how to remove the carbs as well as how to clean them and adjust them.. You also need to install an in-line fuel filter. Once again jus search the forum for this topic.

 

ok i will

 

OK i have all the carbs took apart and i cleaned the best as i can with no carb cleaner cause i don't know were to buy some on Easter Sunday. i also took off the cover to the valves to see if it is on time and was wondering if it has an auto tensioner because i can pull the chain up and it fills loose and then ill turn it over and it will go tight till i pull it again

 

Yeah, if you have bits of Permatex RTV Silicone lodged in the drilled passages, you're gonna have fun getting that stuff out, if that's what's going on.
I've found that brake cleaner is even stronger than carb cleaner.
There are at least 4 loooong carb cleaning threads here with all the details.
Take your time, good luck.

 

Stop being in a hurry.

Get carb cleaner spray and get then really clean.

If you have no gas getting into bowl #1 then leave the carbs off the bike and solve that problem.

Your life depends on the bike running well. Do not take shortcuts. Do try to hurry up the process of getting your bike running properly.

 

ok when i took apart the carbs they didnt look like there is anything wroung with them. i think it is something else would there be anything else the would make it pop other then the carbs being dirty. could it be the they are out of sync or need to be tuned

 

I had similar problems at one point where I had back fires in the exhaust and some that flamed back into the carb/air box. The airbox caught on fire because I was trying to use start fluid to get it going. Plugs were bad and the carbs still weren't right. Took care of those things and everything was happy.

I have to wonder how silicone got into the carbs.

You need to put something through every passage that will dissolve silicone without damaging the carb parts. I don't know what that would be, but that is what needs to be done. You *might* also want to check the YICS passage ... could be someone tried a makeshift tool to sync and left debris in there?

 

ok i cleaned the carb hella good but just more popping there has to be something else wrong. i still havent tried new spark wires cause i cant afford $256 +tax for new ignition coils so ya i got it for free and the guy said it runs just needed ignition coil so i used the ones off my dads xj since he dont ride it lately (and it is the same thing so they should work)

 

Try the $10 fix with a dremel tool and some epoxy. There are a few threads around on how to salvage your coils very inexpensively (in terms of time, much more expensive).

 

ok ill go look at that but the sparks dont look weak, also i kinda mesed with the pilot srew to clean everything if that has anything do do with wat is going on. i turned all the them three turns out from all the way closed

 

ok messed around with the pilot screws and it started to back fire more so i thing it might be starving for gas wats the seting for the screws they have to be pretty far open because im almost to the end and it is still back fireing and also wat is the hose on carb 3 go to

 

2 3/4 out is common but three will get you moving. I am not well versed on carb tuning so I expect to be corrected if I'm off base here.

 

ok i tuned it to 2 3/4 turn and it was more on sync like it would fire on one side then the other then through the carbs

 

o and i forgot to tell you guys i have a custom harness if that can be a problem

 

A custom WIRING harness? Could be a pretty significant clue. Has it ever run CORRECTLY using this harness?

Please think about this carefully before you answer. The help you get from the incredibly experienced and gracious experts on this forum can only be as good as the information you feed t them and your ability and desire to follow their advice exactly to the letter. Dot every I and cross every T then report the results.

You have been on this forum to know whose advice you can and should trust implicitly and without reservation.

All of us are pulling for ya man. We want to see you get this thing on the road and purring like a kitten.

I need to do the same with mine. I want it to run as flawlessly as a 28 year old bike can run. Mine is useable as it never misses a beat up to nearly 6000 rpm. Still needs to be fixed though. I have other bikes to ride so I'm waiting to get a 1200 lb lift before I tear into the Maxim.

Too old, too fat, too lazy to lay on the garage floor anymore.

The lift will $ore than pay for itself in labor savings in the first year. My new ride requires a 12000 mile service that costs $1500 at the dealer. Parts cost? Just less than $300. 2 1/2 hrs labor just to remove the Tupperware at $80 / hour. Oil change? $110. Filter/loil cost? Less than $30. Lift just paid for itself. Abs brake Unit failure? $3500. Can't fix this one. Please pray for my ABS unit and my final drive bearing. $1500 to repair and known 4% failure rate. Must be repaired at dealer. The risks associated with buying a 2001 model year bike. Chacal, your prices now seem like an absolute bargain!

Loren

 

MN-, Harbor Freight has their pneumatc 1200 lb lift on sale now and with the 20% off coupon it is less than the reg price for the hydraulic lift.

I'm thinking that the 1200 lb lift with extensions might have the size/ weight capacity to lift both the bike and the sidecar.

That's my plan anyway! Thanks for the recommendation.

One last thing. On the other forum I read a guy posted that last night he almost dropped his bike off his HF lift at its full up position. He had the bike strapped down o the table but did not have the front wheel in the lock. He said the stand jerked a little bit when he started to lower the table, the bike came off the center stand, rooled forward and came to an upright stop balanced on the skid plate and the rear wheel. What kind of sound does 850 lbs of plastic wrapped motorcycle make when it falls 2 1/2 feet and lands on a concrete floor. Probably sounds kind of like Oh Sh!t!!! Hello Progressive?


Lock that front tire down!

 

ok no i haven't seen it run with the custom harness but i also haven't seen it run period, but he said it would run. i used this diagram to make my custom harness but i seen they made it wrong so i anded the starter relay and it sparks almost continuously on all the spark plugs