Balancing Throttle/ Intake Ports

[lad]

Setting my TPS/ baseline as per
https://archive.guzzitech.com/EVTuneup-Jeff_B.html

i don’t have a twin max, but i do have a carbtune, will that work? and is this the port i would tap into?

[Wayne Orwig]

Setting my TPS/ baseline as per
https://archive.guzzitech.com/EVTuneup-Jeff_B.html

i don’t have a twin max, but i do have a carbtune, will that work? and is this the port i would tap into?

Yes those ports.

Twinmax sucks anyway. The carbtune is no doubt a much better tool then the spastic meter on a Twinmax.

[Tom H]

IF you have some metric grease fittings. You can make a vacuum hose connector out of them. You need to remove the little ball and spring so that it's just an open tube. Some will unscrew to get the bits out. Others you may need to drill the end open more so the bits come out.

They may thread all the way in. If they don't, just a thread or two will do. Just needs to be snug, not very tight.
Tom

[pehayes]

You're going to be tinkering with this adjustment for some minutes.  Make sure to mount a nice box fan up front to blow cooling air over the bike. 

Patrick Hayes
Fremont CA

[lad]

Might have to rely on the cool weather and my windy location, Patrick.

The carbtune comes with vacuum ports so that's fine.

Can anyone explain this linkage thing to me? I see two bolts, the top one just seems to hold the thing in place? No idea what the side one does, but according to this write-up I need to tinker.





So I'm about to start at step 11, and I think I'll be fine until 14, when I have to adjust the aforementioned screws ? I also don't get how it can balance when I'll have just balanced at step 11 using the throttle body screws, then balanced again at step 12 using the airbleeds...?

[Tom H]

In your picture, it looks like the LH TB.

Long screw above the nut balances the LINKAGE between the two TB's.

To fully set the TPS. You should have had to adjust the little screw at about 2 o'clock. That was the LH idle adjust. You set it first with the voltage of the TPS.

Step 11. Now move to the RH TB and you will see the same small screw that you adjusted on the LH TB. You screw that in until you get balance between the TB's.

When you open the air bleeds 1/2 turn, they will change the balance a little. Adjust them so that the TB's are in balance again and the reves are as mentioned.

Step 14. This is where you adjust the long screw I mentioned. The tie rod between the two TB's need to just slide back on. You don want it to move the lever when you slide it on. Well getting it over the tip of the pin may move the pin a very little, but it should return back. If it's adjusted too tight or loose, adjust the long screw. This step makes them open at the same time. Rev and hold the rev and get your balance reading, let idle. Adjust long screw and rev and hold again to get new reading, let idle. Repeat as needed.

Tom

[Tom H]

To start with a big  for tackling this. I'm pretty sure I posted this link as well as the text only one:

https://bradthebikeboy.blogspot.com/2012/10/throttle-position-sensor-setting_21.html

This link explains what screws are what.

If in doubt when following the directions from here:
https://archive.guzzitech.com/EVTuneup-Jeff_B.html

Step back, grab your favorite beverage, smoke 'em if you got 'em, and think it through. It's a pretty easy job do, also easy to miss a step. ESPECIALLY for your first time. You just need to make sure you loosened the screws the instructions told you to loosen and adjust them in the order of the instructions.

If you don't think you have things right when your finished. Start over from the TPS voltage and work you way through.. You wouldn't be the first one that had to start again to get it right.

The long screw that balances the TB's at high rpm. If you have worked on multi carb bikes and had to make sure they were all open the same at revs. You most likely used a cable adjuster on each carb. The single screw is like the cable adjuster tha would have been on each carb. With this design, you only have to adjust one screw instead of each cable.

Tom

[Ncdan]

I did my 02 Stone back in the fall last year. I got everything hooked up and one of the guys here on the forum walked me through the process step by step. Mine was off a bit and was able to bring it back to spec. Ran great afterwards.

[John A]

Mig tips work as well.  Most are Metric  and I use the .030 wire size because that’s mostly what’s laying around.

[jcctx]

If you have an infrared thermometer you just measure the temp as close to the cylinder as possible and get them equal. Far easier than hoses, etc.

[lad]

To start with a big  for tackling this. I'm pretty sure I posted this link as well as the text only one:

https://bradthebikeboy.blogspot.com/2012/10/throttle-position-sensor-setting_21.html

Thanks Tom,

I actually forgot about that blog post! I was just working off the text one, but they seem to do things in a different way/different order to each other, so I might just stick to the one and see how that goes, any trouble and I'll start query-ing.

The MV seems to be a prickly point, might see can I go by the degrees a-la-brad

[Tom H]

The bikeboy link has pictures for the screws.

I would stick with the instructions in the text only link. That is the one I use. Worked every time. Well, except the first time Did I mention the stand back with your favorite berverage

Also, in case your as electrically challenged as I am. Remember 500MV is .5V as in 1/2 volt. 525MV is .525 volt.

Tom

[lad]

This mv issue is highly contested

I was told 370, but...





Bradthebikeboy is way up there, compared to Jeff B, although he says the procedure is for the 1.5M.

I'm in a weird grey area where I have the older ECU with the newer TPS, I wonder should I try both mv's. ?  ?

Or go by degrees? I think I had GuzziDiag up and running ok, except there was no option for a P8/PF3C combo...

The weekend begs a few experiments either way

[Tom H]

I just helped a guy with a P8 and PF3.

I followed Jeff B's guide. It worked. Use sewing needles, sewing pins, a broken in two paper clip to slide down the wires as the guide suggests.

DO NOT use Guzzidiad for the TPS voltage. Only use a multimeter! Make sure you see. "." in my voltage. As in "."150 volts.

With the PF3, back off all screws per Jeff B. With the plastic link bar undone and all screws backed off. "Adjust/rotate" the TPS to aprox. .150 Volts . .152 would be fine. Then tighten the TPS screws and leave them alone.

Then screw in the idle screw until you get aprox. .525 Volts. And then follow Jeff B's guide to balance the TB's and the air bleed screws. If you are unsure of the screws, look at the picture guide.

Sorry that your fighting with it. I had problems the first time. You will most likely have an  O crud moment, that is what the instructions mean.

If following Jeff B's instructions doesn't solve your problem, Then it is something else. The issue with a certain throttle grip position is usually the TPS

Setting the TPS isn't hard, you just need to do it right. Been there, done that!!!

Tom

[lad]

Ok,

so the good news, the great fantastic news, is that the symptoms are gone! FIXED 

Not sure was it the TPS because I didn't baseline and balance with the old TPS, but more than likely it was. I'll hang onto the old one anyway and test it when I have too much free time.

The not great news is it's backfiring pretty bad, sounds like fireworks behind me after I accelerate.

Apparently this can happen after balancing and can be resolved by enriching the idle mixture at the trimmer?

Before I do that, I might just run the stats past your eyes in case it's my balance.

So the base is .150, but the idle (?) is then only set to .365 I think, as per PF09 instructions, so maybe I should raise it up to the .525 first?

Balanced throttles then, and set the idle too 1100, but this took about 1 and a 1/2 turn of the air bleed screws, which seems high compared to the instructions. I wonder if I'm set to .525mv and less air bleed would that sort it out?

It's not the worst to tinker with, mega thanks for the help on it, the sunny weather here now has a whole new prospect

[lad]

Hmmmmmmm

I made a whoopsie...forgot to cap those intake ports, could well be the source of my lean mix....

[lad]

Made a bit of difference, still a bit of backfire when cruising after accelerating

I tried set mv to .525 but the idle was up at 13/1400 like that, that's with everything backed off and air bleed in. No way to lower it from that is there? Might have to go back to the lower, or hook up Diag and try by degrees....

[Tom H]

Congrats, sort of!!! Your getting there!

Stick with .525.

You did make sure the plastic linkage between the TB's easily slid over the pin it goes on right??

If you followed the Jeff B instructions. I would back off the RH TB idle screw no more than 1 turn, less is better. That should get the idle down to the aprox. 1100 rpm. Or...Try turning in the air bleed screws a bit and see if that works.

When you  have it idling right.....

Use Guzzidiag to look at the fuel trim. Write down the number it shows in case you want to go back to it. With the engine up to temp, use guzzidiag to adjust the trim. I feel zero is what you would want. But......Try 10 increments and let it idle for a few moments, you will notice a change for better or worse. My EVT is +15, you might need more or less. If you need more than +40 with a stock bike, I would make sure your TB's and TPS are set right. Now you know how to do it, it only takes a few minutes.


Ooooopppppsss Forgot. P8. Try adjusting the fuel trim with the screw on the ECU. Just a little bit at a time. You will notice a change in idle in a moment or two. When your satisfied, ride and see how it does.
 
Tom

[JoeB]

Forgive me if I'm mistaken, but following your posts I think your dealing with the large p8 computer box?
Did you try any adjustments to the pot on the box?

[lad]

Congrats, sort of!!! Your getting there!


You did make sure the plastic linkage between the TB's easily slid over the pin it goes on right??

yep, slipped on no bother.

I can’t back out the RH adjuster, it’s fully out, and the air bleeds are fully in, linkage is off, ‘choke’ is off, and idle is 1400 at .525

[lad]

Forgive me if I'm mistaken, but following your posts I think your dealing with the large p8 computer box?
Did you try any adjustments to the pot on the box?

P8 yes, haven’t done anything yet. was hoping it was set up right and wouldn’t need messing there but it’s my next stop. maybe valves first though

[lad]

diag says i’m only at 2.29 degrees on the throttle, so maybe .525 is the way, but then my idle is mad

CO trimm says 37. what’s the number about?

[Wayne Orwig]

The P8 idle is 2.1 degrees, or about 385mv.
The 15M computer idle is 3.6 degrees, or about 525mv.
Both use 150mv baseline (idle stop backed out).
You should NOT be using 525mv at idle on a P8.

I'm not sure if Guzzidiag is displaying the trim pot value there or not.

[pehayes]

‘choke’ is off,

Make sure to study the 'choke' linkage.  It is nothing more than a cam which causes a slight advancement of throttle.  You could do exactly the same by hand throttle, just not so gently.  It doesn't directly do anything to fuel mixture.  That mixture is 'computed' by your P8 and delivered via timed injector discharges.

I concur with Wayne.  Your P8 needs to be 385mV +/-.

Patrick Hayes
Fremont CA

[Tom H]

Not trying to start something here, but.....

Is the .385 volts for a P8 with a  PF9 or with a PF3? Or does it not matter which TPS it is using?

I just helped a friend with a '98 with P8/PF3 (all screws backed out including the fast idle, bleed screws fully in, completely starting from scratch) and set the LH TB, TPS side to aprox. .385 volts. Tried to balance them. Wouldn't idle worth a damn.  Backed out the RH and set the LH to aprox. .525 volts. Now I was getting somewhere with the idle. Balanced the TB's with RH idle screw. That got me about 800 rpm. Adjusted  air screws to get about 1100 rpm and then set the linkage and balanced the linkage at about 3000 rpm. Now that bike was running sweet. There was no fast idle cable, so I did not adjust that screw, I just left it backed out.

Tom

[Tom H]

yep, slipped on no bother.

I can’t back out the RH adjuster, it’s fully out, and the air bleeds are fully in, linkage is off, ‘choke’ is off, and idle is 1400 at .525

When you set up the TB's. Did you also back out the Fast idle/choke screw? If that was making contact, it could be throwing off your adjustment.

Tom

[lad]

everything was backed out (air in).  i was the same as you Tom and couldn’t get it to idle at all at .385, i had to have the RH in a touch, surprised that yours was so low with .525.

I just learned how to do it so i can’t really trouble shoot. it’s running quite well now apart from a backfire. back fire is cool no! ??

[Chuck in Indiana]

back fire is cool no! ??

No.    I wouldn't go any farther until I adjusted the valves as recommended by others. That is square one before you start tuning.

[lad]

No.    I wouldn't go any farther until I adjusted the valves as recommended by others. That is square one before you start tuning.

Yeah I think I'll do that, makes the most sense and they probably need to be done.

[Wayne Orwig]

everything was backed out (air in).  i was the same as you Tom and couldn’t get it to idle at all at .385, i had to have the RH in a touch, surprised that yours was so low with .525.

I just learned how to do it so i can’t really trouble shoot. it’s running quite well now apart from a backfire. back fire is cool no! ??

Something is off. Valve adjust maybe. Air leak maybe.
Do you have GuzziDiag?