Another 650 Stopped Starting All Of A Sudden

Ok, so I'm the idiot who bought a 650 a few months ago without having the space to work on it.

Luckily my friend's friend is a mechanic and he did a lot of the initial work at a great price.

- Checked brakes, front and back
- Took of rear wheel and cleaned out the crud (and checked brake)
- Rebuilt the front suspension
- Primed and installed a new battery
- Then cleaned the carbs because all the oil and gas leaked out the day before I picked it up.
- I think he put in a new filter too

Ok, so it worked fairly well for a few weeks, put on 500 miles. Lots of fun.

But...

It slowly had more and more trouble turning over and starting, and never did like to idle. I thought it wasn't getting enough gas - and opening the choke would get it running.

Now I let it sit a week - the battery is strong and it really tries to turn over, but it won't catch, or fire. Not sure of the proper term yet. It chugs for a few seconds, then I have to wait a couple seconds, and it will chug again... but nothing.

From what I can tell I have to do a bench sync?

I thought because of the way it slowly started having more and more trouble starting, and because how it won't idle well, that might be a significant clue as to why it would slowly get worse over two weeks, and then give up after a week.

The last time I rode it it took several tries to start it... more and more... each time over the two weeks.

The good news is when it runs it seems strong enough.

Do these clues give a clear picture of what it might be?

Thanks guys...

 

I'm not expert, but have you check your spark plugs? That's the first thing that stands out to me that you didn't list as replacing.

 

Is it stopping starting all of a sudden? Or is it starting stopping all of a sudden?

You say all the gas and oil drained out? I hope you cleared the crankcase of all the gassy oil since that's where the gas would end up, unless you know for a fact that it ALL ended up on the floor. Then, I hope you put fresh oil and a fresh filter in.

When you cleaned the carbs, did you COMPLETELY dis-assemble them? As in, ' the church of clean' clean? Read that thread several times then do it.

Did you clean the airbox? New filter? You said you think "he put a new filter in" . . . .is that air or oil filter?

have you checked valve clearances? Have you checked your mixture screw settings?

Last, double-check the charge on you battery.

There's a starting point for you.

Dave

 

Funny Dave, yes it's doing a lot of neither of both.

Thanks guys. It was a new fuel filter he put in. No, I didn't check all the other stuff.

The battery definitely seems strong. I just tried to start it again and once or twice it almost caught and turned on, but no dice.

Would the spark plugs be a likely culprit? If the battery is good and the engine chug chug chugs but it never catches?

I don't know if the mechanic achieved the church of clean clean on the carbs but I have a feeling it's one of the other things.

Are the valve clearances and mixture screw settings something I can do fairly quickly without disassembling too much and pissing off the fascist condo board?

But I'm still hoping on the spark plugs... I don't think he changed them... Could I just look at them and tell if they're new (3 weeks old) or not?

Maybe lick them and hold them to my nips to see if they buzz?

 

As with a lot of folks who've bought an old bike thinking it was like an old car, there's no quick or easy solution to your dilemna, I'm afraid.

You need carb service, which includes getting the valves in spec and a lot of DENTALLY precise cleaning and adjustment.

Look in "XJ FAQ Suggestions," where you'll find things like:

How to check and and adjust your valves: http://xjbikes.com/Forums/viewtopic/t=14827.html

Part Deux: http://xjbikes.com/Forums/viewtopic/t=29209.html

Your symptoms are those of a bike in need of carb service, and maybe (pray NOT) the effects of long-neglected valve clearances.

Like I said, no quick or easy fix; hopefully just reversing the effects of long-neglected maintenance.

Get the valves in spec and do a compression test before you sink a whole lot of time and effort into what we're gonna hope isn't a lost cause.

ANY 30-year old bike presents the same set of issues; you have to understand that going in. You have some work to do. Start by tracking down a shop manual.

We're here to help, but you're gonna be turning the wrenches. Get a leg up by doing some research; it's not a quick process. I'd stop riding it until you're sure you're not on the short road to burnt-valve city (and hope you haven't already arrived.)

 

Make sure your Pet-self-censored is delivering the liquid hydrocarbons put it on PRI and give it a try

 

I still smell a burnt valve (or a valve/valves so tight it won't compress anything anymore.) Betcha.

How many miles on this bike? (Our answer lies hidden in the answer to that question.)

You might want to do some more reading. "Bench sync" comes AFTER valve adjustments, carb cleaning, and float levels. But before "running vacuum sync with YICS blocked.")

There's work to be done here. Plus then there's the front brake...

 

I tried to tell him...............

 

Many many miles on the bike, 42K.

So, if the valves are burnt is it just a paper weight now?

 

valves won't be 'burnt'. Just your clearances can get so close (tight) that the valves won't close all the way. What happens is that the valves recede into the head, then if it's not corrected, the valves will ride on the cam all the time and not close all the way, causing obviously a drop in compression. the shims are replaced w/ thinner shims to re-aqcuire the correct clearances to allow the valves to close properly again.

Burnt valves would be because of extremely lean running conditions, which is more a carburetion issue........

so, clearances........do your clearance checks, do the math, and get the correct shims to swap.

Burnt valves, pull the head and replace the valve(s)

These bikes will run 100k+, so don't think you're about whipped yet......

Dave F

 

An exhaust valve that's not closing completely will quickly get burnt; it only takes a few hundred miles if the clearance is down so far it's not fully closing. (Speaking from rude experience here.)

But as Dave said, a couple of cooked valves is NOT the end of the world. It just means a bit more work is all.

But let's don't jump to conclusions. Get them in spec and test compression.

 

Thanks... so does it sound like it's NOT a spark plug issue? Someone just gave me this advice:

"i had the same problem check the spark plug get a new one spray some carb cleaner down in where the spark plug goes open the gas tank lid and light a lighter in the hole the spark plug came out of trust me it sounds stupid but it works just make sure the the gas tank is open and the gas is shut off and drained out out of the carb. you can get a spark plug at any auto store for that bike and its only about 3 bucks"

 

quote:

Someone just gave me this advice:

"i had the same problem check the spark plug get a new one spray some carb cleaner down in where the spark plug goes open the gas tank lid and light a lighter in the hole the spark plug came out of trust me it sounds stupid................................"

-----------------

STUPID is the word that I'd use, too. Someone who gives you advice to spray some carb cleaner in a cylinder, open a gas tank, and then put a lighter to the hole is NOT someone that I would EVER trust.

Yup, you can get a new spark plug for about $3. After the explosion from said lighter at said hole, you can get another XJ for under $3,000 bucks, and your medical bills will probably balance out at around $30,000, and you should be recovered from most of your injuries my about 3 years from now.

Dave

 

Can you turn on your video camera when you begin this procedure? --- There may be a good opportunity for a feature video on Josh 2.0

Just kidding obviously...

 

yeah, it sounded kind of dangerous, oh well

 

(any logic to it though?)

 

This is your answer. Spark plugs alone won't fix this, sorry.

 

First of all, who is "someone"? That clearly was intended to be a joke, but if it came from a member of this site, they should be ashamed, because who knows what a newbie might try.

In case you still don't get it: Logic goes something like this (carb cleaner in spark plug hole ignites, lighting gas tank fuel vapor, then everything goes boom) <- cruel joke if you actually try it.

Maybe the mods should delete any of the posts with that "advice"...could be dangerous if someone new thinks this might be some kind of quick solution.

Your answer lies in what Fitz has posted. Not starting is the result of either no fuel, weak spark, or poor compression, or any combination of the 3. You need to methodically check each one. And no, having your carbs rebuilt by someone else does NOT check the fuel delivery off your list.

 

Ok, well I'm glad I didn't try it, and my future kids thank you.

Gonna replace the spark plugs later today (without blowing up bike), pray, and then see.

I'm up for a good job today, so if I get it then I can afford to get work on the carbs and valves...

 

::: WARNING :::
::: DANGER :::
::: DO NOT ATTEMPT :::

>> Don't give Dangerous Advice <<
>> We do not want you to Post advice or hearsay techniques that could lelad to someone being severely injured or worse because YOU heard something ::>>|| Outside of this Forum ||<<:: to recommend to another Member.

Such as this advice appearing in this Thread:

"i had the same problem check the spark plug get a new one spray some carb cleaner down in where the spark plug goes open the gas tank lid and light a lighter in the hole the spark plug came out of trust me it sounds stupid but it works just make sure the the gas tank is open and the gas is shut off and drained out out of the carb. you can get a spark plug at any auto store for that bike and its only about 3 bucks"