Ignition/Carburetor Problem

[djmarklong]

Hi.

I've got a 1986 FJ1200 that I bought back in April, and rode it back to my home state of Illinois from Ohio.

I've had to fix a few things since then, like the slave cylinder on the clutch, and the fork seals, but other than that my FJ has run fantastic.

Until now.

It's kept outside, so I usually keep it covered. Every once in a while, I go to start up the bike in the morning, with full choke, and it'll rev higher than it should be (about 3500rpm) and blow whiteish smoke out of the Supertrapp exhaust (which admittedly has a few cracks in it, right around the mounting area. I'm aiming to replace it soon). So, I'll turn the choke off, and then if the engine doesn't die, I twist the throttle and this happens:

http://youtu.be/jVNgDHMhMoE

If you can't watch that video, the tach drops to zero, although the engine still runs, it just sounds like it's really struggling.

If the engine does die, I won't be able to start it back up. It'll turn over and run for about 2 seconds, and then die.

The weird part about it all? The bike will run fine in the afternoon when I get home from work.

I ran it by a few people I know, and firstly I thought it was an ignition problem. So I replaced the spark plugs, and then did a test that was suggested to me to test out the ignition coils where you start the bike up and spray water on the ignition coils, and I suppose if they're bad they will spark, which they did not.

Anyway, the plug replacement seemed like it worked, but then two days later, I had the same problem you see in the video.

So then I was told it may be a carburetor problem, and to check the diaphragms inside the carbs. So, I checked all 4 of them, and the 3rd one looked like it was somewhat dry, and it looked like it was very minorly worn, but nothing terribly out of the ordinary (I have pictures, if that helps).

I got a quote from a parts store on replacing all four of those diaphragms, and each OEM diaphragm was $170!

So at the moment, I'm a bit frustrated and not sure what to do. Before I take it into a shop, I wanted to see if any of you have had this issue, or have heard about something like this happening? I think it may have something to do with the humidity because this hardly ever happened in April, May, and June, but we've had a hot and humid summer.

Thanks for your help!

[Paul1965]

I know a few things about cars, but bikes I'm still learning. With that said though, I think you're issue is definitely electrical/ignition. The tach is usually fed it's signal by the coil, and I think it's clear that yours can't handle the load of increased RPM, hence the running rough and backwards reading tach. I'd go get a cheap spark tester where you can adjust the gap and test it at each plug (similar to this, but make sure it fits in the smaller boots of the FJ http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_ignition-spark-tester-lisle_22982553-p?searchTerm=spark+tester) before I pull carbs apart. It also wouldn't hurt before even doing that to make sure you've got good clean connections, especially on the ground side of things. I hope this helps...

[movenon]

I assume you have done the basic things like check your air filter. It might be in the fuel system. I would start at the tank first. I think you have a vacuum line going to your petcock ? Make sure it is hooked up and in good shape (no vacuum there = no or min fuel) fuel starvation. Before it started did you have the tank off ? Check the fuel line routing. It is important that the lines are routed correctly and nothing is pinching the lines.

The vacuum diaphragms can be repaired / coated with liquid rubber if there is a pin hole in in it. Don't run out and buy new ones yet....

That will get you started. sounds like fuel starvation to me. Randy at RPM can trouble shoot it better than me.. Thanks for the video that really helps everyone a  lot in giving advise ! Good job Mark and if I haven't said it  "Welcome"  
Where are you located ?
George

[djmarklong]

Thanks for the help guys!

That spark tester seems like it would help a bit. I've got both an AutoZone and an Advance down where I live. I think I'll have to make a stop there soon.

George - I'm located in Central Illinois, in the Bloomington/Normal area, if you're familiar.

I commute to Peoria daily for work, and because of that I've already put 3000 miles or so on the FJ since I bought it. It's a ton of fun to ride on the boring highway. I did check the air filter, and it looked normal, but I will post pics that I took of the carb diaphragms and the air filter when I get a chance.

Thanks again! I knew I'd be able to find help here!

EDIT - I forgot to mention I checked the vacuum tube from the petcock under the gas tank and it seemed okay, and the main gas line seemed okay too. I tried to put it back the best I could, but it may have been pinched, although I'm unsure it's a fuel issue because I think it would happen every time I rev up the bike. This only happens intermittently.

[movenon]

No need to post pictures of the air filter. Intermittently... umm.  You have checked the battery cable and battery ground ? I would go through all the connectors and there is a bunch of them. If you do, remove your tank and remove the left and right dash panels. You now can see most of the connectors.

The reason I ask where you were located is because sometimes there are other members in the area that can help, or at least drink your beer while they watch.  It is a smaller world than you think at times.

George

[Dan Filetti]

That sure seems like an ignition issue to me.  The tach should not go backwards.  That simply has to be a big clue as to what's going on -seems to me.

Dan

[movenon]

Dan I was thinking the tach was going down because the engine was dieing down.  This will be an interesting one to follow. Hang in there Mark !

Looking for electrical things... Might remove Ignition plate (?) cover on the left side (4 Phillip's head screws) and check that the ignition pick up and timing plate are on tight and not moving around. Check the wiring. 
George

[djmarklong]

I should clarify this happens almost exclusively in the morning, around 8am or so when I'm all geared up and ready to go to work 

In the afternoon, the bike fires up no problem.

This issue has only happened twice while riding. That hasn't happened in a few months, but it made the same noise and I had the same issue when I twisted the throttle. One time I had to wait a few minutes before I was able to get it back to life.

If I have free time this week or this weekend, I'll have to take the fairing off and check all the connections. I have a lot of wires to check.

George, are you talking about the CDI box, or is that different from the ignition plate?

[Paul1965]

I should clarify this happens almost exclusively in the morning, around 8am or so when I'm all geared up and ready to go to work 

In the afternoon, the bike fires up no problem.

This issue has only happened twice while riding. That hasn't happened in a few months, but it made the same noise and I had the same issue when I twisted the throttle. One time I had to wait a few minutes before I was able to get it back to life.

If I have free time this week or this weekend, I'll have to take the fairing off and check all the connections. I have a lot of wires to check.

George, are you talking about the CDI box, or is that different from the ignition plate?

I still think this is ignition related. In the morning it's cooler and chances are your plug wires/coils are full of moisture from sitting outside overnight (I'm a little north of you in IL and know how humid this summer has been, could be even worse if you're putting a cover over the bike). You choke it, starve it of air and it runs fine, until you add more air by taking the choke off and put a load on the system by twisting the throttle. Come afternoon, everything has dried off so it runs just fine. There's 2 things you can try: Spray around the coils and plug boots with some WD40 and see what happens. WD40 has always been known to displace moisture and temporarily cure these kinds of issues. The other thing to try is to hose it down with water (cold engine of course) then start it and see if you find any arcing from the coils, wires, etc (helps to do it in the dark).

[FJ_Hooligan]

Clean any and ALL electrical connectors you can get your hands on.  Pull the tank and clean the coil connectors.  It looks like you're losing the 2/3 coil, that's what is causing the tach to drop to zero.

You could try swapping the coil connectors and spark plug wires (2/3 go to 1/4) to see if it follows the coil.  That might narrow things down a bit.

[movenon]

George, are you talking about the CDI box, or is that different from the ignition plate?

Sorry if my nomenclature is off a bit. No, the plate I am referring to down where the pick up coil is. Yamaha calls it a rotor. I am not holding my breath that's your problem but you need to start somewhere in the system. Could be any connector or part in the system. Hopefully it is just a connector or switch problem.

Could be as simple as the kill switch corroded or shorting. When you are checking the connectors take a look at the main wiring bundle on the right side up in the front where it squeezes between the frame and fairing. You will have to unscrew the right air scoop to see it.

George

[fj1289]

What shape is the battery in?  A weak battery or one that has a cell or two going bad can cause some weird ignition problems. I'd suggest taking the battery in and getting it load tested.

[djmarklong]

I have not had the battery checked, I'll do that!

In fact, it sounds like I've got a lot of things to check, so hopefully it cools down here in Central Illinois and I can check it all.

Thanks for all your help and suggestions! I'll report back what I do find!

[djmarklong]

Okay - update.

So I pretty much took the whole bike apart, checked all my connections (which were clean), checked all four plugs for spark (of which I got spark from all of them), got the battery load tested (which also had a fine charge).

So that left the CDI box...and as I unscrewed it, some white powder came out...and it looked like this:

http://imgur.com/sJM8mZD

...which I don't think is supposed to have that white powder in it. It looks like some serious form or corrosion.

Any ideas?

[Pat Conlon]

Do you read the newspaper? Watch TV?  Then you know that the Internet is monitored, correct?

Do you really want the DEA to see this?

You may want to take down that photo, sooner rather than later..