New engine chirping and running on 2 cylinders

Matt Rain

Matt Rain

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So I dropped an '89 Radian engine into the FJ600. Same engine but with a different stator and pickup coil setup - so I'm using a Radian CDI and rectifier as well. I had to splice a bunch of wires to replicate the Radian's wiring. Everything is as per the manual.

The motor fires up but it produces a chirping sound that increases in pitch and speed when I rev up. Also, only cylinders 1&2 are actually firing - plugs 3&4 are getting wet-fouled. If I pull the plugs out I get a nice blue/purple spark from all four.

My one theory is that the coil pairs are getting triggered backwards, but then wouldn't the engine not run at all?

I'm tempted to connect the coils the other way around (i.e. swap their 12v connectors) so that the CDI triggers them in the reverse order. What's the worst that can happen?
 
On a 4 stroke, you are protected against anything catastrophic happening if the plugs are firing at the wrong time. I have had a car motor run on a few cylinders with timing way way out.

Chirping sound is concerning, post a vid.

I wonder how what you need to actually trigger the cdi? Could you pull all of the plugs, turn on the ignition, put the bike in gear and turn it over with the rear wheel to see if the spark is happening near TDC compression? I don't know if turning it over this slowly will trigger the CDI.

How much do you know about the donor engine? Have you heard it running? How much of an inspection did it get before it went in?
 
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Update - the chirping was an intake leak. Loose carb boot. Duh.

Am much less concerned now that the alarming noise is gone. Probably just bad plug wires and/or caps.

Engine is a fresh rebuild and I'm in daily contact with the guy who did it. He swears it was in top shape and ran like hell. Amateur guy but not his first rebuild - I've seen and heard his other bikes and have no reason to doubt him. He ran this engine for 50kms post-rebuild and took it out 'cause the alternator was putting out too much current. (I had the same issue until I splurged on a new aftermarket rectifier.)

Anyway this thread may be for naught - I'm now 90% certain I just need to fix the plug wires/caps on 3 & 4.

Cold compression is 145-150 across all four cylinders. Can't wait to get it going properly.
 
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I might as well give you some content since I started the thread. Here's plug #4 firing outside the engine.

[video=youtube;RSQsC1x-SAA]https://www.youtube.com/watch?v=RSQsC1x-SAA[/video]
 
And here it is NOT firing while inside the engine.

[video=youtube;mMuRYwhgk04]https://www.youtube.com/watch?v=mMuRYwhgk04[/video]

Engine is surprisingly eager to keep going even though it's 50% deactivated.
 
Be careful not to look directly at the valve cover more than five times or it starts leaking.

Did you lose the oil cooler, or was there a way to hook that up?
 
TwistedKestrel said:
Be careful not to look directly at the valve cover more than five times or it starts leaking.

Did you lose the oil cooler, or was there a way to hook that up?
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lol, the FJ's valve cover did randomly seep oil from different areas. Part of the old school "charm" I s'pose.

Haven't looked into the oil cooler yet, but I believe I can move it over from the FJ's engine along with its shorter oil filter housing. Oil cooler seems to be mounted to some sort of adapter?
 
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So I redid the plug wires and caps and made extra-sure the resistance was within spec, then I put in brand new plugs and fired her up. Same thing - running on only two cylinders, 1 and 2.

**** me.

Then when I removed spark plug #1, a little cloud of black smoke came out of the hole... seems obvious that my timing is way off.

Someone talk me out of swapping the 12v connectors on the coils... seems like the only logical solution at this point.
 
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this is interesting.

curious, have you tried the fj cdi ? are the plug in ends for both cdi's the same?
I have nothing ...maybe double check spliced wiring? soldered?
 
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Matt Rain said:
So I redid the plug wires and caps and made extra-sure the resistance was within spec, then I put in brand new plugs and fired her up. Same thing - running on only two cylinders, 1 and 2.

**** me.

Then when I removed spark plug #1, a little cloud of black smoke came out of the hole... seems obvious that my timing is way off.

Someone talk me out of swapping the 12v connectors on the coils... seems like the only logical solution at this point.
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try it. Worst that could happen is it runs properly.
edit: as you mentioned the puffs of smoke indicate spark timing is wrong. oooor plug caps on wrong cylinders...crossed on the non firing side...
 
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It's one coil goes to the outer two and the other goes to the inner two, right? And firing order is 1-2-4-3?

That's kinda weird that the left two run and the right two don't. What ignition parts are still FJ600? And just for the record again, which ones are YX600?
 
So I tried swapping the connectors and the engine just cranked, no boom.

Outer two, inner two and 1-2-4-3 is correct.

I'm using a full Radian ignition system. FJ CDI can't be used cause the old engine used a dual pickup coil setup, with two signal wires going to the CDI. This late-model Radian engine has only one signal wire and a flywheel around the crankshaft with two magnets at 180 degrees of each other triggering the CDI. Guessing they're reverse polarity which is how the CDI knows which coil to trigger?

Gonna try swapping the two pickup coil wires now. I did it while the coils were wired the other way and the engine wouldn't start at all. Maybe everything was wired backwards originally?

Next step will be to pull the valve cover to double-check the timing. Fun times.
 
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Matt Rain said:
So I tried swapping the connectors and the engine just cranked, no boom.

Outer two, inner two and 1-2-4-3 is correct.

I'm using a full Radian ignition system. FJ CDI can't be used cause the old engine used a dual pickup coil setup, with two signal wires going to the CDI. This late-model Radian engine has only one signal wire and a flywheel around the crankshaft with two magnets at 180 degrees of each other triggering the CDI. Guessing they're reverse polarity which is how the CDI knows which coil to trigger?

Gonna try swapping the two pickup coil wires now. I did it while the coils were wired the other way and the engine wouldn't start at all. Maybe everything was wired backwards originally?

Next step will be to pull the valve cover to double-check the timing. Fun times.
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when you get it back to running on two cyl's try swapping the plug cap leads on the non firing side.
 
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boyoboy said:
when you get it back to running on two cyl's try swapping the plug cap leads on the non firing side.
Click to expand...

I'm pretty much 100% certain the coil pairs are supposed to be 1/4 and 2/3, just as they were in the FJ, but what the hell, I'm game.
 
So you have 1/4 on one coil and 2/3 on the other coil and only 1 and 2 are firing? Isn't that just flipped plug wires for 3 and 4?
 
boyoboy said:
when you get it back to running on two cyl's try swapping the plug cap leads on the non firing side.
Click to expand...

GreyGhost said:
So you have 1/4 on one coil and 2/3 on the other coil and only 1 and 2 are firing? Isn't that just flipped plug wires for 3 and 4?
Click to expand...

I wish that was it but I just tried swapping 3 and 4 and the same thing happens - 1&2 are firing and plugs 3&4 are just getting wet. Again I do get spark on plugs 3&4 when they're out of the engine.

Valve cover will come out shortly. Ugh.
 
Matt Rain said:
I wish that was it but I just tried swapping 3 and 4 and the same thing happens - 1&2 are firing and plugs 3&4 are just getting wet. Again I do get spark on plugs 3&4 when they're out of the engine.

Valve cover will come out shortly. Ugh.
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Can you look down the spark plug hole to see valves without pulling the cover?
 
Any chance 1 and 4 need to be swapped with each other? And 2 and 3 swapped with each other?

Try the wires on one coil first and check the outcome.
 
I already pulled the cover, and I believe I've found the culprit.

Looks like the timing rotor/flywheel may have moved relative to the crankshaft. If I visually set piston #1 at TDC, with the cam lobes pointing directly away from each other, the "T" mark on the rotor is off by a handful of degrees.

97b70a7b5192281d2c7adf5a41bfe053.jpg


e272981b3158925b0e055ae478485d25.jpg


Discrepancy doesn't seem all that large though, and the cams do seem to be in sync with piston 1's TDC.

Should I pull that rotor? (If so, what kind of puller do I need?)
 
I think that is supposed to be keyed to the crankshaft... but the "key" might be removable and possibly left out? Just going by the fiche and it's a bit ambiguous
 
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