Problems and more problems

I'm getting tired of throwing money into this bike and about ready to take it the scrap yard or sell it for parts..anyways I have an 81 xj650 the engine will turn over but not run I did get it to pop of but had the throttle all the way back and as soon as I let off it died.

 

You are gonna have to elaborate a little more than that, what's going on?

 

Really it just tries to turn over that's all. Nothing more then that it. I got it to start 1 time with the throttle all the way open but when I let go it shut off

 

By elaborate he's asking what work you have already done to the bike. You have had posts about it before, but I don't think you've mentioned this specific problem.
So make us a list: what work has been done so far.

 

All new gaskets set on the engine, valve clearance done, new battery, new clutch plates.

 

'81 650. This ^ , new solenoid and rebuilt the starter. The only bright light on the cluster is the oil light (He checked the bulbs in the cluster; they're ok). This was taken from other threads he posted in.

Gary H.

K-moe and others will probably reply here shortly. The advice given will be spot on. If I can add anything I'll do so then.

Gary H.

 

I also have new after market gauges from dime city cycles that work fine

 

So you haven't cleaned the carbs?

 

Damn no doing that now tho, I benched synced them that was all

 

Clean the ever loving shit out of them. Make them sparkle. Look at the end of one of the jets, and look at how tiny some of the holes are. One tiny piece of dirt that even gets in there and restricts the flow of fuel, and you're going to take them all apart again.

The worst part about taking the carbs off is taking the carbs off, so do it right and get it done. Clean everything out two or three times while they're off until you're confident you won't have to take them back off again once you manage to get them back on.

If you don't you'll be kicking yourself over it.

I'm not even going to link you to Church of Clean, I'm sure a dozen people have thrown it at you already.

EDIT: And make sure you drill out the brass plugs and remove the pilot jets too.

 

And wet-set the fuel levels. That is as critical as anything.

 

Are the plugs wet or dry if it tried to start full throttle and then died sounds like the floats are high making it very rich but could be either way will know more if we can get some more information

 

I think I'm gonna end up selling it tho, now have a kid on the way I really can't invest anymore time and money into it.

 

The brass caps are over the mixture screws.

If you haven't CLEANED the rack, you're gonna have nothing BUT trouble.

 

It's not money that you need to invest, it's time and effort. It'll cost you $5 to clean the carbs, and that money will be spent on gumout carb cleaner.

It's worth more running than it is sitting, get it running, then sell it.

 

Remember this if you go to buy another bike . . . .

A 34 year old precision machine needs to have maintenance done to it.
If you don't have time and an extra $600 - 800 to make it reliable and safe, and if you just want to ride, don't buy a 'vintage' bike. Then come to a forum and bemoan that the bike is worth nothing but scrap . . . .

 

+1 Stumplifter

 

How do you wet set the floats. I'm sure it's somewhere on the forum just can't find it

 

What about carb dip? I know it can eat away rubber seals tho. So do u need to take every jet out and clean them out, pretty much just take the whole carb apart completely naked?

 

As mentioned earlier the carbs must be correct for it to start and run right. Imo the best thing to do is disassemble the carbs. If you don't the dip will eat the shaft seals and o-rings (which should be replaced anyway). It's a process the first time but once you do it you'll learn the different parts and better understand how they work which will make troubleshooting much simpler in the future. Remember, we're here to help.

Gary H.

 

Carbs can only be dipped when the decision has been made to replace the throttle shaft seals and fuel rail O-rings - typically recommend as they are over 30 years old. If you don't replace all the 30 year old rubber (throttle shaft seals, fuel rail o-ring, pilot mixture o-ring, and float valve needle), it is very likely you will still have problems with either tuning, gas leaking, or gas overflowing.

Here are most of the applicable links to get the carbs in good working order:

http://www.xj4ever.com/hitachi%20throttle%20shaft%20seals.pdf

http://www.xjbikes.com/forums/index.php?threads/how-to-clean-the-enrichment-circuit-well.8918/

http://www.xjbikes.com/forums/index.php?threads/in-the-church-of-clean.14692/

http://www.xjbikes.com/forums/index.php?threads/how-to-bench-synch-your-carbs.6366/

http://www.xj4ever.com/setting%20fuel%20levels.pdf

And if you don't take enough pictures this one is handy:

http://www.xjbikes.com/forums/index.php?threads/first-time-taking-apart-carburetors-lots-of-pics.48063/

 

Thanks guys I won't give up

 

Right on!

That's the spirit.
People here will help as you go.
We have electronic wizards; mechanical wizards, fluid wizards, even bacon wizards here.

 

Thanks guys I won't give up

 

Since it is raining today in good ole Florida, I will be hitting the carbs.

 

take plenty of pics on the teardown of your carbs....

 

Uh--- rrriiiggghhtt, shur......

It's cost a lot more than that to do them CORRECTLY and THOROUGHLY.

Yes, do take pics and notes... But know that if you are unsure of anything, ASK. That's why we're here.

Very true, too, if you decide to sell anyway-- it is definitely worth a lot more running than not.

Hang in there. My black full-dresser ( in the showcase) was a non-runner when i got it. It turned into a stone-reliable bike and got to a 2nd place trophy. It's now on the second owner past me and going strong at 50k on the odometer.

 

I know how you feel, Bubba. I've been waiting to ride mine for months, and with a new arrival expected, the timeline just keeps getting longer... I try to stay sane by reminding myself how much sweeter the prize will be due to the work I've put into it and the wait only adds to the sweetness! At least that's what I tell myself when I sit and stare at it...

 

Alright guys holy shit got it started but umm started and shot up to 6000 rpm any suggestions?

 

I think I tightened the idle screws all the way down, not knowing what they were. How should I got about adjusting it? I did bench sync the carbs too

 

Turn all four idle mixture screws out 2.5 turns from soft-seat for baseline to begin with.

Turn your idle speed screw out to bring rpms down. Then do a running sync and colortune

 

I hope that by tightened you don't mean actually tightened, and really mean screwed in until they lightly seated.

 

Where is the idle speed screw? Any pics?

 

The idle speed is the knob on the back of the carbs between the #2 and #3 bowl. It will open and close all the butterflies simultaneously. The high idle could be caused by a few things. Did you wet set the fuel levels in the carb bowls? Have you checked for vacuum leaks?

Gary H.

 

From the bench sync how to by Gamuru:

 

your bike should idle at 1,050 rpm's after it is warmed up.....& choke is off......turn the idle adjustment screw all the way out....& then backed in until it impacts the throttle plate & adjust it until 1,050 rpm's is acheived...

 

Thanks guys for all the help I will let you know what happens tonight. I really needed yesterday, it put a little wind in my sails made me very happy.

 

You may find that you need to "split the difference" when setting idle speed. Set it at 10,50 RPM when hot and you may have difficulty starting it when it's cold. Set it for easy starting when cold and your idle when hot will be too high. Warm is the key. Setting the idle speed when the engine is warm enough to run without the enricher, but still not to full operating temp will get your idle speed where it needs to be.

 

alright guys I have to missing something. I backed everything out all the way and still goes up past 6k rpm, now is I hold the choke up all the way it does slow the rev up but still goes up to 6k

 

Now I do have a rigged aux tank just a Gatorade bottle with gas and a house going to the carbs. The line that goes to I'm assuming the vacuum on the petcock is not attached to anything

 

Is the vac line capped or plugged? If not that's part of your problem.

 

The vac line from the petcock is supposed to be hooked up to the vacuum port on the #3 carb intake boot (but any of the 4 ports will work).

 

I have it on number 2, I just plugged it and it's still doing the same thing

 

what do you mean by "everything".....we were referring to just the idle adjustment screw between carb 2 and 3..........what else did you back out......

 

The screws next to the choke levers. I even put them back to where they were with the idle screw backed out still same thing

 

Those are the idle mixture screws and they need to be adjusted is a very specific way. I am going ot assume that they are back at 2.5 turns out form a soft seat now.

I am going to ask a dumb question just to clear up a common problem.
Are you 100% sure that the throttle cable is hooked up to the throttle linkage on the carbs? It is really easy to flip the choke and throttle cables around during instillation.

 

Yea I'm sure I twist the throttle and it will go higher. And the are 2.5 turns out now.

 

Can anything else cause a problem other than the carbs? Like an exhaust leak or something like that. I know I may sound stupid but I don't have the exhaust tightened all the way down its just kinda fitted on for right now and I don't have the air box boots on.

 

It seems very much exactly like there is a vacuum leak. Did you inspect the intake boots for cracks?
You can take an unlit propane torch, or carb cleaner and use that to search for vacuum leaks. Go over every seal and rubber part from the throttle shaft seals, all the way to the intake ports on the head. Be methodical. When the engine speeds up even more you have found a vacuum leak. Make a note of where it is.

Also; yes, not having the air box and filter installed, and not having the exhaust on correctly can cause the engine to idle high. The lack of an air filter makes it run leaner (like a vacuum leak does) and the lack of backpressure on the exhaust side exacerbates the problem.

 

Well tomorrow sounds like a button everything up day. I appreciate the help I will let you know what happens next.....to be continued