Throttle balance question

[nwguy]

I'm on step 11 of Jeff B's "Late model Cal/EV FI Tuneup Procedure" with my 99' Bassa:

https://archive.guzzitech.com/EVTuneup-Jeff_B.html

It'll only run for about 30 seconds when I start the bike,  then sputters and dies and won't start again. The repeated start attempts have run my battery down so I'm having to recharge it between new attempts.

The bike was not warmed up before starting this at step 3. I adjusted the valves a few days ago. My TPS base and idle settings seem spot on even after briefly starting my bike. The high idle (choke) cable is adjusted so there's freeplay with the lever off, but it'll move the right side TB linkage when the lever is pulled. I've pulled the choke lever when trying to start it.

I've done this procedure a couple of times before, but only with the bike warmed up. I'm thinking this is probably the difference. Any suggestions?

[Guzzidad]

   Sounds to me like a failed electric petcock.

[guzzisteve]

It is designed to give a bit of throttle (choke lever) when stone cold, that sends signal of richness to ecu. I didn't look at the steps or video, just saying how it works. For batteries I use a 12V35AH AGM U-1 Group They last 12 years, You can crank forever w/o fail My storage space has no lectrics, I let them sit 4-6mo at a time, they go all the time.

OK, now I looked-------- With the screws closed it won't want to idle SO you have to give it the gas to keep running till you get the airscrews open 1/2 to 3/4 open

**** Hope this works

[nwguy]

Thanks Guzzi Steve. I'll try that after I replace my battery. Now with the charger light green, not orange, it won't turn the engine over.

I have a new manual, not electric petcock.

[guzzisteve]

That batt I use is for scooter in  the grocery store. $100 at Batteries+ Crank all day.

https://www.batteriesplus.com/productdetails/SLADC12=35J?storecode=652&source=google&medium=search&campaign=ecommppc&gad_source=1&gad_campaignid=23501381673

[Wayne Orwig]

Do you smell fuel? (too rich) Maybe pull a plug and check.
Sounds like the TPS is set wrong. What are you setting it to? You do have a 15M ECU under the left side cover, right?
Are you hearing the fuel pump run as the motor cranks?

[n3303j]

That batt I use is for scooter in  the grocery store. $100 at Batteries+ Crank all day.

https://www.batteriesplus.com/productdetails/SLADC12=35J?storecode=652&source=google&medium=search&campaign=ecommppc&gad_source=1&gad_campaignid=23501381673

I'm surprised a deep cycle battery designed for electric vehicles is providing service in a Cold Cranking Amps application. I couldn't even find a CCA specification on that battery. Certainly is cheaper than Odyssey. What service life are you getting from this battery?

[elrealistico]

This is what I used to set mine---lotsa pictures---


https://www.bikeboy.org/tpssetting.html

[nwguy]

At this point I've pretty much memorized both Jeff B's and Brad the Bike Boy's guides on tune ups including valve adjustment, TPS setting and TB balancing.

I have the 15M ECU.

My baseline TPS setting is around 148-149 mV. For idling, with the left side TB stop screw in it's about 510 mV.

The fuel pump does come on when I turn the key. Hard to hear it going with the starter engaged and spinning the engine. I'll pay more attention to that next time.

guzzisteve: When you say "you have to give it the gas to keep running till you get the airscrews open". How would you do that with the TB linkage arm disconnected on the left side and the choke cable's stop screw backed out?

Mobility scooter battery, hmmm...

[guzzisteve]

quite simple, you leave it put together till it's running, you do not need circlips. I have no circlips on mine for over 10yrs. I can tune anytime in 5min.

[Tom H]

I see the problem your having. When you go to start the bike, use your finger to manually open the non tps side TB just a bit, that should get it to start. Once it's running for a moment, use should be able to let go of it.

To be clear on the instructions. Once running you will be using the non tps throttle stop screw to balance. Then open the bleed screws for best idle and balance again using only the air bleeds only.

And with respect, the engine will idle with the air bleed screws screwed all the way in. Some bikes like one side closed and one maybe 1/4 turn open. Most seem to be about 1/2 turn out.

Tom

[guzzisteve]

Did you get this resolved?

[nwguy]

No. I bought and installed a new Odyssey battery. I re-baselined the TPS and the idle setting. Got it idling by slipping the left side TB linkage arm on the left TB and rolling on a bit of throttle. I thought I got the rest right, went for a test ride and it ran poorly. Came back and reinstalled the old TPS. Maybe my cleaning the new one with deoxit hurt it. Seemed to run better but I can't get it idling between 1000 and 1200 rpm and balanced. Still rides poorly. Turning the air bleeder screws in or out seems to have no effect. I tried them 1/2 turned out per instructions, and cleaned them last year with q-tips and denatured alcohol. Should they be blown out with compressed air?

I've done this procedure semi-successfully at least 3 times in the past, but had a high idle. That's why I thought I'd do a whole tune up over again, to fix that. Not sure if I'll be able to fix this, and am reaching my limit on how much time I want to spend on this. Somewhat devastating after everything I put into this bike since I bought it last April. Am pondering alternatives now for my XC trip in May.

[n3303j]

Please don't get discouraged. Sit back & relax. Think about the process. Sip a beer and watch some cat video shorts. Working on the machine is for relaxation and eventually success. Stop looking so hard at the goal and just go ahead and clean and examine stuff. When you are just cleaning it tends to let the mind wander and consider alternate paths to the ones that have gotten in the way of success. I did field service, later I had a team that did field service. It's amazing how many times an unresolved issue got solved after the tech left the office and was 20 minutes down the road. Mind was free to wander and the solution appeared.

All in all this motorcycle thing is for your enjoyment. Do not let it get you down.

[nwguy]

Sorry for this long post, but here's more complete information on what happened.

------------------
Loosened TB stop screws and choke cable stop screw so not in contact with stops.

With new battery and using diagnostic cable, set baseline TPS to approx. 150 mV.

Turned in left side TB stop screw to set TPS idle setting to approx. 510 mV.

Temporarily reconnected left side TB linkage arm. Started bike and got it idling so it could warm up. Was idling low as expected.

Disconnect left side TB linkage arm.

Carbtune manometer showed the right TB with a lower reading. The right side rod was very low, almost not visible.

Turned in right side TB stop screw so balanced, and idle speed became too high.

Not knowing what else to do, I loosened the left side TB stop screw to bring the rpms down. I don't know what the TPS mV were at that point, but must've been lower than 510.

After adjusting both TB stop screws, got it idling at around 1,100 rpm and balanced. Seemed balanced at higher rpms too.

Opened left and right side air bleed screws a half turn. Had no effect. Turning them out even more still had no effect. Left them at a half turn out.

Went for a test ride. Herky-jerky throttle response, major lack of power at times. Made it a couple of blocks and returned home.

-------------

It's strange because this bike had a serious flat spot in throttle response on my ride home from buying it last April. After my first tune up it ran well. Flat spot gone. Did some nice day rides on it. I did a couple more tune ups after buying a new TPS and ended up with the idle too high. I didn't see in either Jeff B's or Brad the Bike Boy's tune up guides on how to simply lower the idle speed after completing a tune up, thus the repeated tune up attempts.

If you didn't read this earlier post comment, an oil leak from my new crank position sensor install got oil all over my new TPS. After cleaning the TPS with deoxit and blowing it dry with a compressor, I reinstalled it. I had to rotate the TPS all the way to one end of its rotation range. Suspecting that I damaged it with the oil and deoxit, I installed the old TPS. At 150 mV it was set roughly in the middle of its rotation range. Maybe I need another new TPS.

The nearest MG dealer said they wouldn't work on my Bassa(too old) even though the prior owner had them do some repairs. Even if they were willing to, I need to know how to do this myself to own this bike.

I did have a beer after this yesterday. 

 

[Wayne Orwig]

Sort of sounds like the throttle plate on the left is not going fully closed and hanging open a bit (or an air leak), messing up everything you try to do.
All of that extra air may even explain why the air screws don't work.

[guzzisteve]

Just use the idle stop screws equaly to rais or lower rpm, don't have to be 510mv. What ever it is to make it idle at 1000-1100 is what it is every one is different at 25yrs old. My base line is +15mv at 165 for open airbox & exhaust, snapped closed too. Try again you'll get it.

[nwguy]

If I remove the air bleed screws, is it safe to shoot compressed air up there to make sure the orifices are open? Like I say, I've previously removed those screws and cleaned everything I could reach with a q-tip.

[guzzisteve]

Pull & shoot up some cleaner, then you know not plugged.

[nwguy]

By virtue of the cleaner draining back out?

For cleaner, wd40? Penetrating oil?

[guzzisteve]

I use carb cleaner & compressed air. I use oring lube on screw orings but you can just use some engine oil.