Topic: 76 550K wont fire right on 1-4 video added!!

[JAG]

I just pick up another bike and I can only get it to run off of cylinders 1 and 3.

I know that they are getting spark.
I know that they are getting fuel.
The timing has been set.
carbs gone through.
new spark plugs.

Could it be a valve problem? I'm going to recheck the clearances tomorrow. But I don't think it would cause the cylinder to not fire at all.

What else am I missing here?

Ive ran out of options.

[Stev-o]

I'd pull the float bowls to confirm fuel is in there. Gas lines run as close to vertical as possible??

[scottly]

I would check the spark plug wires: the wire going to cylinder #2 should go to the same coil as #3, and #4 should go to the same coil as #1. Just a guess, but easy to check.

[JAG]

I'd pull the float bowls to confirm fuel is in there. Gas lines run as close to vertical as possible??

I unscrewed the drain and they all have equal amount of gas in them.

I would check the spark plug wires: the wire going to cylinder #2 should go to the same coil as #3, and #4 should go to the same coil as #1. Just a guess, but easy to check.

The coils and wires are as they should be. Blue Fire is jumping when checking the plugs.
The 1 - 3 cylinders that aren't running, when I pull the plugs the plugs are wet with gas. So I know fuel is getting to them. I know the plugs are firing when I check them.


I'm going to try to change the wires around and see if the problems follow to the other cylinder. But if they don't what is left to check?

It's got fuel..
It's got spark..

-boggled-
 

[Duanob]

Compression issue?  Bent valves not closing? If it were electrical as in coils or timing it would usually effect the 1 & 4 or the 2 & 3. If it were w petcock issue it would effect your 1 & 2 or your 3 & 4. Sounds weird to have 1 & 3 unless it's a fluke.

[JAG]

Well I've been messing with the plug wires and making sure fire is getting to them. I have a bunch of D8EA Spark plugs for the 750s so i just threw them in there to see what it would do. I replaced the 1 and got fire but lost it in 2. Replaced 2 with the d8ea and got back fire. Going for number 3 to see if the same works then it'll be hitting on all 4.

But what's the Danger in using different plugs?

[Stev-o]

You may want to ohm out your plug caps, mine were bad last year. And clip ends of spark wires.

Plugs have differant heat ranges, you want to be in the correct temp:

http://www.ngksparkplugs.com/tech_support/spark_plugs/index.asp

[JAG]

Still nothing on 3.

Instead of checking ohms I just switched the cap with one that was running and the problem didn't follow to that cylinder that I switched. Still no fire from 3.

Checked tappets on 3, and they were a little off but still no change.

Cut back the wire some to get fresh wire coming through.
Spark flies off the wire. And spark flies off of plug when cap is back on. Bright blue.

Has plenty of gas going to it, but still won't fire. 

[Stev-o]

compression?

[JAG]

compression bad on only one cylinder?
How do I check that? I don't have any special gauges to check for compression..

[Stev-o]

If you have spark and fuel, next check is compression:




Something doesn't sound right?

[JAG]

If you have spark and fuel, next check is compression:




Something doesn't sound right?

Where can I get one of those?

[Stev-o]

If you have spark and fuel, next check is compression:




Something doesn't sound right?

Where can I get one of those?

http://www.jcwhitney.com/engine-cylinder-compression-test-kit/p2020220.jcwx?filterid=c21475m213j1

[jimkalfakis]

You have over 700 posts and you don't know where to get one of those? Okay, almost any auto parts store will sell a compression gauge. Not expensive. If you own an old CB then it's a must have. Remember, three things you always need to have combustion. Fuel, compression and, spark. It should at least fart with those. Good Luck! I hope it's something stupid.

[Duanob]

I just boguht the bigger comp tester kit from Harbor freight it works pretty good and cheap too. Make sure it has a 12mm adaptor.

[JAG]

You have over 700 posts and you don't know where to get one of those? Okay, almost any auto parts store will sell a compression gauge. Not expensive. If you own an old CB then it's a must have. Remember, three things you always need to have combustion. Fuel, compression and, spark. It should at least fart with those. Good Luck! I hope it's something stupid.

Never needed one. And to rephrase I know where to get them but I knew there needed an adapter to fit our bikes.

Like Duanob said I know to get the 12mm adaptor.

I really hope its something stupid too. But I think I've tested everything that is stupid with no intelligent results. Haha.

[JAG]

Okay I got the compression gauge. I only had time to test it on two cylinders. I tested it on one that has always ran good and the dreaded number 3 and got them both to shoot up a little passed 90psi.

I kept messing with the spark plugs, the wires, and the caps and some how or another I got it to fire off all the cylinders. I let it sit and idle for a few minutes and then the big "uh oh" occurred..

I noticed oil pouring down the right side so I shut her down and began searching for the dreaded leak and come to find out it was coming out of the breather tube.

I checked the oil level and it looks to have almost 2 quarts OVER the limit mark of the dipstick.

So tomorrow its off to drain oil, put new in at the appropriate amount and see if it keeps doing it. If it does it looks like it'll be a complete top end rebuild on a bike that is turning out to be a lemon..

[JAG]

Oh and compression test was done with only the two spark plugs out and I used the start button I don't think I held the throttle wide open and the engine was cold.


Sooo rookie mistake. Disregard those numbers. I'll do it correctly tomorrow.

Famous word from Homer.  Doe!!!!

[scottly]

then the big "uh oh" occurred..

I noticed oil pouring down the right side so I shut her down and began searching for the dreaded leak and come to find out it was coming out of the breather tube.

I checked the oil level and it looks to have almost 2 quarts OVER the limit mark of the dipstick.

Don't panic; you merely over filled the oil tank. It happens all the time with dry-sump 750s when they sit for long periods of time.

[Spanner 1]

+1, common mistake IMO with bikes that have sat for months/years.... new owner freaks-out when they see the oil tank empty  , not realising that the oil has leaked-down to the sump ( normal )  and then fills up the oil tank = oil capacity x 2 

[scottly]

Just re-read the title of this thread. Is the bike in question a wet-sump 550??!!

[Spanner 1]

OMG.. yes, wet sump motor.......... 'DOH' 

[TwoTired]

If you have two quarts over fill, then check to see if the gas level has gone down.  Carbs overfilling can leak into the intake runners, past the intake valves, go past the piston rings, then settle into the oil sump.  Gas in the oil is NOT a good thing.  Change both the oil in the sump and in the oil filter.
Be very wary of bad/stuck/blocked float valves in the carbs, and make it routine to turn off the gas when the engine is not running.

[JAG]

Yeah I never checked the oil when I brought her home I just started tearing into her.

I got it from a friend of mine and knew he only messed with it when I was around.  I know with it running in the garage for those very brief moments of time it smokes up the place and smells terrible of gasoline. I just assumed its from sitting for so long.

I'm going to replace the oil and filter. I need to download the manual and find out how much oil it takes with it not having an oil tank like the 750s.

[JAG]

Okay wow. There is no reason why there should be this much oil in the bike!!!

Unless like TwoTired said there may be gas in there as well.

Holy Hell Batman!!

I know I never left the gas on unless the PO did.

Guess ill be going back through the carbs.

I never had any gas running out the carbs since I brought it home and cleaned and adjusted float height.