What does it feel like when a spot is rich or lean??

Quote:
7. Engine accelerates until the midrange then pauses, stumbles, or shuts down until you back off the throttle. This problem gets worse the higher the gear used.
• Verify the parameters on the Fact Sheet are being met. For example, the mains are stage 1 mains if you have the stock air box. The stage 3 mains are used with the individual filters.
• Verify the intake and exhaust flow matches those described by Dynojet.
• Verify the float bowl vent tubes are removed (not applicable to Pressurized Air Box Models).
• Verify proper installation of parts, spacers under the needle etc. as Dynojet recommends, and that your needles and mains are all matched and free of obvious defects.
• If these items check out, lower the needle down to fix a slight pause or stumble. Lower the needle and install a smaller main jet to fix a more severe problem.

Almost seems to fit the symptoms... I've had a smaller, 160 main in there... Maybe I need a 155?? I'm grasping now, obviously... I've tried to do the "choose the correct main first" route, but I can't GET into the mains with it stumbling like this at WOT... so how the heck do I do that!?

Hahahaha... you guys DID warn me that Pods were fun! Not ready to turn back just yet...

Where did you get that little explanation from in this post??

[49er]

Glad it's sorted. IMO, GS 850's are the most comfortable/sweetest performing combos available! Hey, but I'm prejudiced.

Oh, and I was right about the XD vs XB plugs... it's just a diffenence in the rubber boot on the plug end. The hold in the XD is smaller for the 10/12mm plugs... I used the rubber bits on these two caps from my original caps and all is good!

Zoom!......

Problem SOLVED, guys!!

And, it turns out that the bad plug caps were NOT the issue... They didn't help, but it turns out that 49er nailed it!

I took it for a ride with the new caps, and it WAS better, but only in that it would struggle through the stumbling a LOT better... the stumbling was still there.

SO, I pulled over, filled up with gas, and while I was parked, pulled out my screwdriver and pulled out the factory air-cleaner side rubber stacks from inside the K&Ns... Problem solved!!

There is a very brief hessitation/stuble right at 7000, but it is just a blip and I'm sure caused by the 170 mains still in there (should be the DJ 165s), and perhaps the needles may need a notch adjustment, but the rest is all golden!

VERY HAPPY GS850 owner right now!

Now I can get to the ignition mods with the coil relay, new coils, and Dyna S... Relay mod first... the others will have to wait a bit.

Thank you all SOOOOO MUCH for sticking with me and providing the good advice. Hopefully others have learned from this as well, but I know I certainly did!

I'm very greatful! Hopefully I can return the favor one of these days!

Gotta go... time for a ride!

[OldVet66]

I was plagued with intermittent coil, wire, cap problems, all of which were new replacements. I finally bit the bullet and got a set of Dyna Green coils, to match my Dyna-S, and the Dyna 8mm suppression wire. All those problems went away and I'll never look back at the stock ignition parts again. The coils and wires made a huge difference in the way the bike runs.

Well... the parts guy at RMC mis-heard me and thought I said "XD05F", instead of XB... I looked them over and frankly, I don't think there is a difference in the base cap itself. The XD is supposed to fit 12 and 10mm threaded plugs, and the XB is for 14mm, but I tried the XD plug on a B8ES plug and it fits just fine.



I'm thinking that the difference is actually in the supplied rubber boots that go over the plug. If that's the case, I'll just use the boots off of my existing caps and should be good to go.

Can't wait to get out to the garage tonight and get this done to see if my mysterious issue is taken care of!!

12-15k for the coil only seems normal. The stock plug caps tend to be ~10k (when they're in spec, obviously) so you get 32-35k total. With 5k NGK caps you can expect that to drop another 10k. That reading itself would not give me cause for concern. Obviously those caps need to go.

Found the new plug caps (XB05F and VB05F) at Renton Motorcycles, just up the road from here, so I'm going to go pick them up at lunch and get them installed tonight. We'll put everything back together with those and see if that helps.

They're $4.25 each there, but it's about the same in the end by the time I pay shipping to order them, and I'll have them tonight...

Hoping this is a positive step towards solving this issue! (fingers crossed)...

OK, Electrical/Ignition findings...

I think I've located the issue...

First the numbers:

Voltage at Battery: 12.4V
Voltage to coil: 11.3V
Coil Primary R: 1-4=4.3 Ohm 2-3=4.5 Ohm
Coil Sec (with plug caps removed, through wires): 1-4=12.08 kOhm 2-3=11.7 kOhm

Now the juicy part... WITH the plug caps on... the resistance through the secondary, WHEN it would read, was well over 200-300 kOhm. I pulled off the plug caps and measured them individually, and they read like this:

1= 8.9 Ohm
2= >130kOhm
3= >200kOhm
4= 71 kOhm

I noticed that the connection inside the end of the cap was loose on all of these, but even after screwing it all the way in, the resistance was still tricky to even read, and when I could get it to read something, it was WAY up there.

I pulled two of the caps apart and found that there was a lot of corrosion on one end of the spring, and just in general.

Looks like new plug caps are on my order list for today.

I'm a little concerned about the coils, as the BassCliff notes suggest that they should be reading 30-50kOhms... but they are only reading around 12kOhms... However, it's unclear if the measurement noted is suppose to be WITH the plug caps attached, or without.

If you could let me know if you think I need new coils, I'd appreciate finding out here shortly, as I'm about to make an order, and while I don't really have the extra $$$ to spend on coils right now, I'm in there, and if necessary, would like to get this done.

Thoughts?

Thanks!

You may just have hit the nail on the head. I doubt that DJ's tuning parameters include people fitting the velocity stacks inside the K&N pods. I'm not saying it won't work, just that it's probably causing an over rich condition when using the DJ recommended jet sizes. If you intend to keep using them, I'd be leaning off both the needle and main jet. May the experiments progress!

I can pull them and give it a try... Willing to try anything at this point...


Tested the voltage to the coils... 12.5V across the battery... 11.3 at both coils with the ignition on (bike not running). Connections looks pretty dirty, so I'll get it all cleaned up. Will research the rest of the wiring tomorrow.

[49er]

Also, for reference, in case it matters... I DO still have the factory "velocity stacks" from the stock airbox installed (well...brand new ones, as the originals got melted in the fire that took place in the factory airbox with the PO)... I have them installed inside the K&Ns. I believe it's important to help straighten out the airflow prior to entering the carb to help prevent unwanted turbulance, especially around the jets at the carb opening...

You may just have hit the nail on the head. I doubt that DJ's tuning parameters include people fitting the velocity stacks inside the K&N pods. I'm not saying it won't work, just that it's probably causing an over rich condition when using the DJ recommended jet sizes. If you intend to keep using them, I'd be leaning off both the needle and main jet. May the experiments progress!

Well, ... nothing except pods and a pipe.

OK, when I say "motor", I'm referring to the core motor... not the support systems...

It's amazing how many guys think we're just blowing smoke when we say that, it's nice to hear you admit it.

I totally believed you, and expected this kind of tinkering/trouble-shooting to be involved. It was a $400.00 bike with 21,000 on it, and was to be expected.

Had the stock airbox been installed on the bike when I got it, I'd have likely left it, but it wasn't, and it's a filthy mess that would take a lot of work to cleanup and re-install, and I like the looks and sound of the PODs, so I'm willing to do the work to make it happen.

Also, for reference, in case it matters... I DO still have the factory "velocity stacks" from the stock airbox installed (well...brand new ones, as the originals got melted in the fire that took place in the factory airbox with the PO)... I have them installed inside the K&Ns. I believe it's important to help straighten out the airflow prior to entering the carb to help prevent unwanted turbulance, especially around the jets at the carb opening...

Yes, it can cause similar problems, but before you go to all the trouble of doing the coil relay mod, just check your voltage at the coils and compare it with battery voltage. You can do this with the engine ON or OFF, but get both readings under the same circumstances. If the difference is less than a volt, you probably won't notice any improvement with the relay.

.

That's my plan! I will be checking everything as it is before I make any more mods... The ignition worked from the factory in stock form. I'll make it work that way again before I change anything else... unless I need a new one, in which case a Dyna-S is in my future!

Thanks again for the tips!

[Steve]

I guess the most puzzling part is that this is simply a stock GS850G motor... Nothing has been done to it that should have it requiring anything special to make work correctly.

Well, ... nothing except pods and a pipe.

Hahahaha... you guys DID warn me that Pods were fun! ...

It's amazing how many guys think we're just blowing smoke when we say that, it's nice to hear you admit it.

So far, I've cleaned up the connections from the battery, through the Ignitor and the fuse-box, and all of the contacts leading up under the tank. Need to remove the tank next and get to work under there. I'll try to do that tonight and get back to you with the voltage.

If it's less than 12V, would that cause this kind of problem??? (REALLY hoping it's something like that!!)

Yes, it can cause similar problems, but before you go to all the trouble of doing the coil relay mod, just check your voltage at the coils and compare it with battery voltage. You can do this with the engine ON or OFF, but get both readings under the same circumstances. If the difference is less than a volt, you probably won't notice any improvement with the relay.

.

No points on this bike... it's a 1980 GS850G...

Hmmmmm.....

After changing the jetting so drastically all over the board and having none of it really affect the actual problem....

I concur. The dusky look of those plugs suggests incomplete ignition.

Yes it can, may have poor quality spark. With a quality spark you may not be too rich.

After changing jetting so drastically all over the board and having none of it really affect the actual problem, I'm leaning this direction at the moment, with the hope of getting a resolution soon.

If that turns out to be it, then I should be able to hone in on the correct jetting pretty quickly.