Kenner nurses a neglected 04F back to health

[Kenner]

Maybe check by pulling one plug wire at a time when it's acting up and see if pulling one has no effect (that's the bad side) or pulling one kills the engine entirely (only good side).

I have a question regarding pulling a plug wire while the engine in running. In the Clymer Manual it warns that the plug wires/coils need to be grounded while performing a compression test so they recommend inserting the spark plug and grounding it to the head while performing the compression test. If I remember correctly this is to avoid a potential overload of the coil.

I have read in a number of places that a good way to test for a dead cylinder (and even a quick way to check carb synchronization) is to pull the plug wire while the engine is running and listen for any changes. Pulling the wire is essentially opening it up, doing exactly what the Clymer manual is warning against. My question then is the Clymer manual recommendation overly conservative and pulling a spark plug wire while running is not risky to the ignition system?

Ken

[mr72]

I've never heard of that risk, but I've never read a Clymer manual either.

I have done the "plug pull" many, many times on a running engine to diagnose issues and never had it make the coil go bad.

The coil won't discharge if it's not provided a sufficient path to ground. I suppose there is a chance that it will become charged sufficiently to break down the lacquer insulation on the wiring in the coil. It's no different though from a bad coil wire.

[gregjet]

Prime use for a laser thermometer. Measure the temp in the same place on the exhaust header near the head. It will tell you straight away.
They are also really good for telling you if your beer or champagne is cold enough.

[Kenner]

Prime use for a laser thermometer.

Grejet,

I read your other post about a laser thermometer and I really wished I had one. I may have to get myself an early birthday present (my B-day is not till April).

Ken

[gregjet]

They aren't that dear. And you have to ask yourself, how much is the correct temp beverage worth?
Even in Aus they are reasonable
http://www.supercheapauto.com.au/Product/SCA-Thermometer-Infrared/321439

[The Buddha]

If yellow bird's carbs run good on blue bird and blue bird's carbs run like crap on yellow bird, I'd likely suspect yellow bird's fuel supply/flow is messed up.
Yes get laser thermometer and other cool sheite ... cos those are just cool as duck ... but your problem could be something far far less cool, like the retarded A$$ petcock and the retarded A$$ other petcock etc ...
Cool.
Buddha.

[Kenner]

I'd likely suspect yellow bird's fuel supply/flow is messed up...your problem could be something far far less cool, like the retarded A$$ petcock and the retarded A$$ other petcock etc ...

Thanks for the idea, but I doubt it is the fuel delivery because I have replaced the vacuum petcock on Yellow with a manual one from a CRF250X (in your words eliminating one retarded A$$ petcock ). Blue still has the vacuum operated petcock and its the one that runs fine.

I could always try a test by turning the fuel on with the lines not connected to the carb and catch the fuel in a bowl seeing how fast it is flowing.

My issue now is that the bike will idle, but if I try to load it (like simply taking off from a stop) it bogs down and nearly dies.  Just to get the bike moving I have to rev it to 4-5K and slip the clutch a lot.  Once moving it will accelerate very slow, but I have yet to get it to go over about 40 mph.

If It sits idling and I twist the throttle it will rev up, but not as quickly or cleanly as Blue will do.

Maybe I should post a video?

Ken

[mr72]

yeah that could definitely be fuel flow. Maybe hook up a fuel container directly (no petcock) and see if it changes things.

[Kenner]

I found the culprit. Turns out the problem was "Fire". One of the Yellow's plugs at the back of one of the coils was disconnected. Not sure if it is the ground or the secondary coil wire but once I plugged it in it ran pretty good. Since it snowed about 3 inches today I was not able to take it out on the highway, but I did do a loop up and down the street a couple of times and if feels like it is running pretty good.

It did backfire a couple of times when it was cold. I didn't notice it backfiring once I warmed it up, but I didn't ride it much either. It has the lunchbox filter on it now and the jetting is set to 20/60/145.

I bought the filter and jets off one of our forum members.

Do others running the lunchbox experience backfiring?

Ken

Circled wire in image below was disconnected.

[gregjet]

Pretty sure , if the 04 is the same as an 05 that there is no earth wire as such. One wire goes to 12V and the other to the ECU ( although the ECU wire is a kind of earth wire).  Just found that out when I was wiring in the coil on plugs.

[Kenner]

Thanks for the info Gregjet.

I started up Yellow again today and took her for a ride up and down the street (not very far since it is about 20°F outside). Yellow now runs better than Blue. Its great!

I posted a video of Yellow running on Youtube here: https://www.youtube.com/watch?v=RsuSAJ3Ht-A

You also get a sneak peak of Blue in the video.

Ken

[cbrfxr67]

sweet! ! ! 

[Kenner]

I got both Blue and Yellow completely put back together today! I decided it was time for a photoshoot. Enjoy!

Ken

Now what to do with 2 running bikes........?

[ajensen]

Good looking bikes--clean and not scabbed. I have always liked the blue ones best, but the only one I found to buy at the right price is black and a little scraped up. I have not seen a yellow one except in pictures. Again, you have good clean bikes.

[Kenner]

Hi all,

I have been riding both bikes for the last month and they are sure fun. The blue one is definitely all round the better bike. It is smoother, feels tighter, and looks better.

I have been contemplating a new project for the Yellow Bird. I acquired a frame from a 2005 KX250F. I have considered putting the front suspension from the KX on the GS making it a little more of an adventure bike.

I did similar to my wife's TTR230. I put the front suspension from a DRZ400 on it that I got from my neighbor after he blew up the engine.

I think adding a stiffer and longer travel front end will make it a blast down simple dirt roads. If I am happy with the new front suspension I'll do something to increase the rear travel.

It'll take a while before I get started since I prefer to ride in the fair weather and wrench during the winter, but it's always nice to anticipate the next project.

Ken

[gregjet]

Kenner,
If you decide to increase the rear travel let me know how much you are aiming at. I have the Tony Foale suspension software and , of course have the gs500 rear suspension already measured and modelled so I can do so simple design testing.
Even though the gs is heavier longer travel usually means lower rate suspension ( though I can model that as well) and get a ball park spring rate for any travel.
Interesting you may be able to swap the shock and swingarm links to get travel increase, though I haven't modelled it yet.

[mr72]

I have been contemplating a new project for the Yellow Bird. I acquired a frame from a 2005 KX250F. I have considered putting the front suspension from the KX on the GS making it a little more of an adventure bike....

I think adding a stiffer and longer travel front end will make it a blast down simple dirt roads. If I am happy with the new front suspension I'll do something to increase the rear travel.

My dad's been looking for a dirt-road bike and he's looked at the usual KLR650s and the like, I tried to convince him maybe he should try a modified GS "scrambler" style simply because I know all about how to work on it. Biggest killer is weight, although it's just about the same as a KLR650.

I bet you'll have to swap the springs in the KX fork. You'll definitely have to increase the ride height in the rear and maybe the travel. A Katana 600 rear shock may get the job done for you; it's a stiffer spring and with any preload at all will raise the rear over an inch while riding. But my guess is you will need a couple of inches, which will mean a different (custom or adjustable) dog bone link.

Sounds like a big project. Also sounds like you'd be better off starting with a different platform to make a dirt-road bike.

Maybe just to ride on gravel or dirt roads you'd just change the tires to 50/50 and handlebar to a tall MX bar or KX bends with 1.5" risers. Swap springs front and rear to get an inch less sag. Put on a round headlight with a rock guard on it and take off all of the plastics. Call it a scrambler.

I guess there's a progression from dirt bikes to road bikes and you can probably modify a GS500 reasonably easily to get it near the 75% mark, while a KLR650 is more like the 40% mark. Your fork swap will get a GS close to the 50% mark if you do the same at the rear, maybe even swap the swingarm and rear wheel. But then that's a rather different bike altogether, and if it were me I'd start with a different bike if that's your intent. I think there are a lot of little things that are not easily altered (foot peg position, length of the tank, low end torque, etc.) that may seriously limit a GS500's usage truly "off road" where there is any obstacle bigger than your two fists to go over. But where there's a will there's a way You've shown you can fix dang near anything if you want to.

[Kenner]

I haven't had much time to work on the motorcycle lately because I have been overseas for a while (in southwest Asia). Since I couldn't work on the bike, I thought I would read a book that I have heard a lot about which I hoped would improve my maintenance skills.  The title is "Zen and the Art of Motorcycle Maintenance: An Inquiry into Values", by Robert M. Pirsig. I came across multiple posts in a variety of forums praising this book. Unfortunately, it was not what I was expecting at all. Honestly, I can say I didn't like it much and it was a waste of time to read. A more accurate title would be "Zen, Philosophy, and two pages about motorcycle maintenance", since that is about all the copy that was dedicated to the subject of maintaining motorcycles.

I am an engineer which means I tend to be more analytical and logical. Reading this book tested both my analytic and logical patience. I was hoping to improve my motorcycle maintenance skills, but instead I was presented with a book that bounced back and forth in timeline, was difficult to understand, and presented odd philosophies. If debating and philosophy are your thing, you'll probably like this book; but since I don't really enjoy either of those activities this book was somewhat painful to read. I realized I'd been duped when I was about a quarter of the way through the book, but I continued and finished it just in case there were any hidden gems.

I appologize for the off topic comment, but since I can't work on my bikes now all I can do is continue to think about them and make plans for what I want to do when I get home. Then posts about actual motorcycle maintenance will continue.

Ken

[Endopotential]

I'm with you on that one!

I thought that book was required reading for any "real" thoughtful biker, but man was that a boring read about hippies on Harleys.

[gregjet]

" Zen and the art..." I read it many decades ago, but I did come to it knowing it wasn't about fixing motorcycles, but fixing people. I possibly saved my life. Not by some mystical whimsy, but but the notion of dumping the crap when you are getting overwhelmed and concentrating on the now and what is in front of you.
Does relate to fixing motorcycles in a sort of "Sun Zu's Art of War" relates to conflict way, if you think about it.

Now back to the yellow...