my xj 650 engine wont start just pops!!!

my engine just pops and doesn't start up i just cleaned the carbs but it still does the same thing it shoots flames out the exhaust at certain times and air comes out the carbs at certain times please help

 

what year is your bike?
was it ever running?
what were the circumstances of it's current demise?
if i was to have a stab, i would say the problem is fuel supply, or lack thereof.

 

its a 82 and i don't know for sure if it was running cause someone gave it to me but he said it will ran but it might be fuel supply because all i did was put some fuel in the lines cause the gas tank it had was all rusty and it also pops out were the chokes are if i raise the choke up and the engine is not on the frame because i am going to put it on a go kart frame if that has anything to do with it

 

First off, it's really hard to follow what someone is saying when they use no proper grammar or punctuation when they write.

i would check the spark plug wires, sounds like they may be crossed.

 

it goes 1 all the way left 2 next then 3 and 4 on the right side if you were looking into the carbs right

 

that happend to be today it was my throttle cable . it was giving to much gas .

 

no it cant be the throttle cable because it ain't hooked up

 

try push starting it, you might need to sit it on a skateboard.

 

how am i suppose to push start it its just the engine

 

laugh and a 1/2 try rolling it j/k

 

Bluepotpie, why are you so hung up on grammer and punctuation? Everyone has their own unique skills. My Dad can't spell for crap and he is one of the finest gentlemen to ever walk the face of this planet.

If you can't decipher the message why not just hang back and let someone else help. This is a forum for 20+ year old motorcycles. If someone can get enough info in a post to get the message across then that should be good enough.

Just my 2 cents. Why do I feel like defecation is about to hit the rotary oscillator?

Just thought I needed to say something befor someones feelings are hurt and they wind up avoiding this forum..

Wamaxim

 

sorry if i came off to harsh here. it's just tough to figure out exactly what someone's saying when it's all one run-on sentence comprised of a bunch of thoughts smushed together. i'm not suggesting anyone needs to be an english major or anything, it would just be nice if they put a little thought into the planning of what they write.

I apologize if i've offended anyone.

Back to the issue at hand. mine did this when i had 2 of the plug wires reversed. On my 750, the coils each have 2 wires going to them. both have a red/white wire and one has an orange, and one has a gray. the one with the orange is for cyl. 1 and 4, and the one with the grey is for cyl. 2 and 3.

Also, as you sit on the bike, cylinder 1 is on the left, then 2, then 3, then 4 on the right.

 

I agree. Sometimes it's VERY tough to figure out the question. Maybe I should get some help from my padre at times like that! The man is 79 years old and just smiles now when we good naturedly tease him a little about his spelling. The whole time I was living at home there was a canister in the kitchen labeled 'Flower". Flower was one of the primary ingredients in cookies, pie crusts, etc. My mother was an avid reader, crack speller, and had gorgeous penmanship but couldn't turn that flower into a decent tasting unburnt cookie to save herself!

Man are we each unique?

Wamaxim

 

I had the same problem with my 750 and changed the plugs and it started. The old plugs looked fine but were not.

 

I believe the wires from the left side coil should go to cylinders 1 and 4. And the wires from the right side coil to cylinders 2 and 3. That's how they are on my XJ700.

 

Scrapkilla, Assuming you have the ignition routed correctly( orange to 1 + 4) and assuming you have adequate compression and a good ground, then it has to be carbs !

* did you see the "beanie screens"?
* did you run a fine wire thru the jet in the float BOWL?
* wire thru the little brass tube?
* remove the pilot screw and little "O" rings?
* wet set the floats? (the flood test)

These carbs have alot of tricks to them. Search : "whole nine yards"

 

I agree with the try changing the plugs as my 87 Ninja wouldn't start. Plugs looked fine but just popped when I turned it over. Put new plugs in and she fired right up. Didn't help that 2 of the plugs were only finger tight also.

 

ya i have the spark wires right. it will still only pop out of the carb and exhaust. i cleaned carbs and they had silicone looking stuff in it .

 

it wont get gas to cylinder number 1 carb but all the others have fuel through the float bowls. and it only pops when i put gas in the carb

 

i did all the things timetoride said and it still backfires and pops out the intake and doesn't get no gas to the first carb all the others have gas in the bowl

 

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

 

and this is how i hooked it up

 

I strongly suggest getting a non-custom harness off of eBay or such.

 

i dont need all that stuff though all i need is the ignition casue all i got is the engine

 

will this harness work

 

PM Dwcopple he has a basic wire diagram.

 

does anybody have Dwcopple wiring harness

 

ok i redid my wiring to exactly the same as Dwcopple except i took out the head light and tail light. i still didnt get it to run because i think it is not getting no fuel into the cylinder just fumes. i also put it on time and put gas it to the first cylinder and it popped after i turned it over for a couple of turns. the spark plugs are black with carbon if that helps to know.

 

If it's fuel-related, you should be able to get it to start and run for a few seconds by shutting off the fuel, locking the throttle about 1/3 open, spraying a bit of starter fluid in each carb throat, and starting it.

If it starts and runs for a few seconds like this, then you're right about it only being a fuel problem. If it still just coughs and backfires, then you've got an ignition/timing problem (perhaps in addition to a fuel problem).

If this test shows it to be an ignition problem, the best next step, IMO, would be to get a timing light so you can verify that 1 and 4 are firing near TDC and that 2 and 3 are firing near #1's BDC.

 

I presume you're getting fuel into all carbs now? they've been cleaned up good and all passages, jets, etc are clear?

I'm assuming the coils are correct, i.e not the other way around? I know it's a wasted spark system so all you could have to try is swapping the primary side connectors around.

If the plugs are fouled I'd give them a good clean up or buy new ones just in case they're past their best.

If the timing & compression is ok, and you're getting a good spark then it'll be down to the carbs.

One way to force some fuel in to the carbs is to have the airbox off, cover up a carb inlet with your hand and crank it over for a second, you should feel suction and it will suck fuel into the carbs, do that for all 4 carbs then try to start as normal (might need some choke to start it). Sometimes I've had to do that to get bikes running after having the carbs apart for cleaning.

 

thanks guys i fixed it im hella dumb it was the ignition coil wires they were backwards orange goes to gray and viceversa