Posted December 26, 2002 - 05:47 AM
Posted December 26, 2002 - 06:21 AM
Is the jetting stock, what elevations and temps are you riding at? Without knowing where your at, I'll throw this out as a start........If its down low (0 - 1/4 throttle, idle)your most likely lean on your pilot jet circuit, not positive on '99s, but stock on an '01 426 is a 42PJ. Where do you have your pilot screw set?? You should be somewhere between 1 1/2 - 2 3/4 out, if you need to go more than that, you'll need to go up one on your pilot jet. Guess what I'm getting at, is if WFO is good, your needle should be close, and your main should be right on.
Posted December 26, 2002 - 07:44 AM
I have a 99 WR also, had a similar popping noise.It was after riding a bit ,stalled, relit using the hot start. The bike then started to pop. It ended up being the hot start valve was not closing all the way so it was just like an air leak.
Only other time I had a fouling problem was getting to carried away with the filter oil, the oil bleeds then gets into carb circuit not good.
I've got the same problem as you, work prevents me from getting to ride as much as I'd like so I dual sported my bike. It's actually really fun,
good luck with the bike, TT threads will get you going.
Posted December 27, 2002 - 04:49 AM
Posted December 27, 2002 - 05:55 AM
I plan on checking the valve clearance while I'm at it. This looks like a pain,is it?
Checking........no, it's not really a bid deal, quite easy in fact. Now shimming on the other hand is supposed to be a whole nother story. I havn't had to shim yet, my bike was completely withing spec as of July...........dang it's been that long, bout time to check them again.
If the time inbetween your rides can be measured in "months", I would also start to suspect your gas. Gas doesn't stay good for too long, maybe a month or so for real freshness, or maybe even less.
Let us know what you find out, or at least post your jetting setup and elevation.
Posted December 27, 2002 - 06:05 PM
Second, check your valves. I just checked mine for the first time since last march and everything is really tight. I need to decrease each pad/shim one side to get back into specs.
Posted December 28, 2002 - 01:07 AM
Remove the octopus (air cut valve) COMPLETELY. The octopus interferes with setting up your pilot jetting system to work PROPERLY.
Install either the KL or Taffy mod to your accelerator pump. My pump stroke time was > 2 seconds (I have heard of 4 seconds!). The magic number is ~ < 0.5 seconds
Re-jet your carb. Bill (senior moderator) has decent jetting #'s.
The accelerator pump on the 98/99 is super wicked prone to seizing up with mud & water. This needs to completely disassembled and THOROUGHLY cleaned. When you disassemble this, work over a real good area where, when you drop the little o-rings (2) inside the AP, you will find them.
You should make it a ritual to VERY THOROUGHLY clean your carb every couple of months (dependent on your riding time on the bike). This does include the air jets. These reside under the air horn on the airbox end of your carb. Use carb cleaner and compressed air to blow ALL passages clear.
Setting Valve clearanc is very easy to do, along w/ shim replacement.
Posted December 29, 2002 - 08:52 PM
1st thing to do is check for air leaks. This includes intake and exhaust. This "octopus" another TT member was talking about is a contraption. You need to eliminate this. Just to eliminate air leaks 1st, Buy a vaccum cap from your local auto parts store 30 cents. Remove the octopus completly and cover the air inlet valve on the head with a vaccum cap. Start your bike and see if it stll pops. Next, if it is still popping put a light behind your bike and wrap it and see if its spiting out raw fuel immediately folowed by fire and a loud pop. I know it sounds strage but a WR with a worn Cam Chain will jump time. Have you done a compression test?
Tighten all air boots and Check that darn air jet in the bottom of the air horn and the filter side of the carb. This thing has a tendency to get crammed with crud and can be easily overlooked. You have to remove the air horn off of the filter side of the carb. Im not sold on cutting the duration of accelerator pump.
Posted December 30, 2002 - 05:39 AM