New engine chirping and running on 2 cylinders | Page 4 | GTAMotorcycle.com

New engine chirping and running on 2 cylinders

Yeah here's the Clymer:

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Both manuals would need to be wrong, which is not impossible. Lots of minor factual errors in both.
 
boyoboy said:
Matt, the small tiny arrow is difficult to see. take a long searching look at your new pics and study the crankcase for the arrow.... arrow is near invisible - this is THE mark on crankcase ..
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I totally know what you're talking about. Tiny little downward arrow. But both manuals clearly show the ridge as being the timing mark.
 
Matt Rain said:
I totally know what you're talking about. Tiny little downward arrow. But both manuals clearly show the ridge as being the timing mark.
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ok. trust me that is the mark, and not a coincidence it lines up. do you have both a radian and fj manual? Do they have colour coded wiring diagrams? The main wiring harness is all fj. the radian harness will be different due to the 1 pick up vs 2 pickup set ups.

it may be a blessing in disguise you removed the rotor for a look - who knows what damage could have occurred in the future from low torque setting. Torque that rotor on and study the wiring diagrams for both bikes...note differences, specifically from the pick ups onward. Im almost ready to bet wiring, no wait, well not really. Im still spitballing.

when wiring, radian wiring trumps. since pick ups and cdi are radian. but harness is fj.
 
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I do have the wiring diagrams and have literally spent days figuring out how to rewire the bike. I'm 99.5% certain that I did it correctly.

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Also, I just tested your theory about the spark plugs all firing at once... first time I find a use for the slo-mo feature on my iPhone (will upload vid in a few mins but anyway, spark is alternating as it should.)

I'm going to get fresh new spark plug wires and try again. I did redo all the caps earlier this week but I reused the same wires after snipping 1/2" off the ends - maybe they're iffy and fail to fire plugs 3 & 4 when under compression? *shrugs*
 
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Matt Rain said:
I do have the wiring diagrams and have literally spent days figuring out how to rewire the bike. I'm 99.5% certain that I did it correctly.

242f788e4f017e050d1e8df3625889bb.jpg


Also, I just tested your theory about the spark plugs all firing at once... first time I find a use for the slo-mo feature on my iPhone (will upload vid in a few mins but anyway, spark is alternating as it should.)

I'm going to get fresh new spark plug wires and try again. I did redo all the caps earlier this week but I reused the same wires after snipping 1/2" off the ends - maybe they're iffy and fail to fire plugs 3 & 4 when under compression? *shrugs*
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dang, foiled again lol. Im going to search for some wiring diagrams on line and take a look.
 
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Is this the mark in question?

sent from my Purple LGG4 on the GTAM app
 
Matt Rain said:
I totally know what you're talking about. Tiny little downward arrow. But both manuals clearly show the ridge as being the timing mark.
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He is right. Both manuals are wrong. The small arrow is the mark you align with not the ridge. There are two, the one at the top is for cylinders 1 and 4, there is another arrow at the bottom to check 2 and 3. Your marks align perfectly on top.
Link to yamaha factory manual pdf.
http://www.badrad600.com/Service Manual.htm

Sent from my SM-A500W using Tapatalk
 
I'm willing to concede that the arrow is the timing mark. Makes more sense anyway.

My slo-mo video upload is stuck for some reason. Oh well.

Will install brand new spark plug wires tomorrow. Let's see what happens.

dnno.gif
 
Spark plugs 3 & 4, the non-firing ones...

[video=vimeo;228299820]https://vimeo.com/228299820[/video]
 
Now that I think about it I think I had the exact same emotional turmoil over the timing mark. I never ended up needing to time anything, only doing valve adjustments, so it probably didn't get resolved
 
Hey, I don't want to re-hash this idea again too much, but I think this is important to try again: on the non firing side only, switch the two leads going to the spark plugs. then try to start up. give it a good try, even letting the bike run on two cylinders for a while to give the cylinders a chance to clear out and fire. This will change the spark timing 180 degrees for each of those two non firing cyl's.

it just makes sense to me (since all four plugs are showing spark).
 
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The two cylinders that are not firing are on separate coils. 4 is with 1, and 3 is with 2.

However, to test Matt's theory that he may still have a bad spark plug wire, I suggest removing the spark plug wires from the coil connected to 2 & 3 and swapping them around. Remove them at the coil like you are replacing with new wires, but instead just swap them around.

Start the bike and if it now runs on 1,2 & 3 the spark plug wire is good.

If the bike runs on 1 & 3, the spark plug wire is bad and Matt's assumption is correct.

If the bike runs on 1 & 2 the spark plug wire is good and you have a different issue.

I mentioned to try this in post #18 but maybe wasn't clear enough.
 
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other thoughts: checking the wires/plug caps is not a bad idea, but i find it unlikely both would fail completely at the same time.

take a feeler gauge and measure valve clearances on the two cyl's - if they are way off the cyl's may not fire, but with a compression of 145-150psi across the board I don't think the clearances are that far off. spitballing again lol.

But then we all know murphy's law.....look see and check
 
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Just to add to my last post, do this first.

You could quickly move 2 & 3 without disassembling the coil and start the bike. Since you know 2 was running, moving 2 over to 3 should get 3 running. If not, then you have a different issue.
 
Robbo said:
Matt, are the carbs from the FJ, or did they come with the radian motor?
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Good question, the radian carbs are smaller. Fj carbs could lead to flooding.

Sent from my SM-A500W using Tapatalk
 
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