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Re: Idle and Throttle Sync Test
Posted: Sun Mar 26, 2023 9:01 pm
by Pio412
hillsy v2 wrote: ↑Sun Mar 26, 2023 6:18 pm
Pio412 wrote: ↑Sun Mar 26, 2023 6:09 pm
Quick thought- could a battery issue cause the problems I'm having? As I stated in a previous post I did replace the battery but what if it's going bad already (faulty)? Since these are battery dependent bikes?
It's possible. Test the voltage at the battery terminals when the bike is running. You should see 13V or so at idle then 14+V at revs.
I will test that and report back
Re: Idle and Throttle Sync Test
Posted: Sun Mar 26, 2023 9:05 pm
by Designer
When you do,...could you please check these things out also?
Pio412 wrote: ↑Sun Mar 26, 2023 6:09 pm
Quick thought- could a battery issue cause the problems I'm having? As I stated in a previous post I did replace the battery but what if it's going bad already (faulty)? Since these are battery dependent bikes?
Possible,...but,..Let me ask,...do you experience any lack of Battery Power when starting?
Do your Lights get dimmer when you turn them on, but do not start the Engine right away?
Why I ask is that I have my doubts about your Sputtering/surging issue being anything related to your Battery.
If it was a weak/insufficient battery, I would think you would have experienced a rather poor starting/cranking situation....along with poor Idling too.
But you say it runs pretty well other than at Cruise RPM.
I'd go with what Herb says, IMHO.
Re: Idle and Throttle Sync Test
Posted: Sun Mar 26, 2023 9:43 pm
by hillsy v2
Pio412 wrote: ↑Sun Mar 26, 2023 9:01 pm
hillsy v2 wrote: ↑Sun Mar 26, 2023 6:18 pm
Pio412 wrote: ↑Sun Mar 26, 2023 6:09 pm
Quick thought- could a battery issue cause the problems I'm having? As I stated in a previous post I did replace the battery but what if it's going bad already (faulty)? Since these are battery dependent bikes?
It's possible. Test the voltage at the battery terminals when the bike is running. You should see 13V or so at idle then 14+V at revs.
I will test that and report back
Re: Idle and Throttle Sync Test
Posted: Mon Mar 27, 2023 9:17 am
by Pio412
Designer wrote: ↑Sun Mar 26, 2023 9:05 pm
When you do,...could you please check these things out also?
Pio412 wrote: ↑Sun Mar 26, 2023 6:09 pm
Quick thought- could a battery issue cause the problems I'm having? As I stated in a previous post I did replace the battery but what if it's going bad already (faulty)? Since these are battery dependent bikes?
Possible,...but,..Let me ask,...do you experience any lack of Battery Power when starting?
Do your Lights get dimmer when you turn them on, but do not start the Engine right away?
Why I ask is that I have my doubts about your Sputtering/surging issue being anything related to your Battery.
If it was a weak/insufficient battery, I would think you would have experienced a rather poor starting/cranking situation....along with poor Idling too.
But you say it runs pretty well other than at Cruise RPM.
I'd go with what Herb says, IMHO.
Good to know , designer... thanks.
Re: Idle and Throttle Sync Test
Posted: Mon Mar 27, 2023 9:26 am
by Pio412
Pio412 wrote: ↑Mon Mar 27, 2023 9:17 am
Designer wrote: ↑Sun Mar 26, 2023 9:05 pm
When you do,...could you please check these things out also?
Pio412 wrote: ↑Sun Mar 26, 2023 6:09 pm
Quick thought- could a battery issue cause the problems I'm having? As I stated in a previous post I did replace the battery but what if it's going bad already (faulty)? Since these are battery dependent bikes?
Possible,...but,..Let me ask,...do you experience any lack of Battery Power when starting?
Do your Lights get dimmer when you turn them on, but do not start the Engine right away?
Why I ask is that I have my doubts about your Sputtering/surging issue being anything related to your Battery.
If it was a weak/insufficient battery, I would think you would have experienced a rather poor starting/cranking situation....along with poor Idling too.
But you say it runs pretty well other than at Cruise RPM.
I'd go with what Herb says, IMHO.
Good to know , designer... thanks
Re: Idle and Throttle Sync Test
Posted: Mon Mar 27, 2023 10:17 am
by Lechy
One thing that has not been mentioned is the battery earth cable, over the years it can denigrate and heat up causing a high resistance giving symptoms of carb problems. For what it costs to make one up (with soldered lugs) it may be worth a shot. Give all mating surfaces a damned good clean and apply di-electric grease when fitting.
Re: Idle and Throttle Sync Test
Posted: Mon Mar 27, 2023 2:16 pm
by hillsy v2
Lechy wrote: ↑Mon Mar 27, 2023 10:17 am
One thing that has not been mentioned is the battery earth cable, over the years it can denigrate and heat up causing a high resistance giving symptoms of carb problems. For what it costs to make one up (with soldered lugs) it may be worth a shot. Give all mating surfaces a damned good clean and apply di-electric grease when fitting.
They ground to the engine then rely on the engine mounts to ground to the frame....but they ground everything else to the frame so it can sometimes lose continuity.
Worth checking (like the charging) but not the OPs problem here - I'd say pilot circuits are still dirty. They can be REALLY hard to get clean when a bike has been sitting for long periods of time.
Re: Idle and Throttle Sync Test
Posted: Mon Apr 03, 2023 5:40 pm
by Pio412
A quick update and a thank you to all of you for your help!
So I decided to rip off the carburetors one more time and give them a VERY, VERY thorough cleaning. Shot carb cleaner through all jets, Reset float heights, blew through all ports making sure the air exited all corresponding ports... etc. That must have done the trick because it's running smoother than it ever has been OFF choke! Finally. Might need to tweak the sync just a teeny tiny bit but I'm very happy with the smoothness it has now!
It's crazy that this actually worked because I THOUGHT I cleaned them well enough last time...
I've been working on engines and carbs for years and these cv Mikunis are by far the biggest pain in the ass to clean
Re: Idle and Throttle Sync Test
Posted: Mon Apr 03, 2023 5:59 pm
by navigator
Courtesy of Lechy:
Most common cause often overlooked are blocked pilot air jets,
Re: Idle and Throttle Sync Test
Posted: Mon Apr 03, 2023 6:32 pm
by hillsy v2
Pio412 wrote: ↑Mon Apr 03, 2023 5:40 pm
A quick update and a thank you to all of you for your help!
So I decided to rip off the carburetors one more time and give them a VERY, VERY thorough cleaning. Shot carb cleaner through all jets, Reset float heights, blew through all ports making sure the air exited all corresponding ports... etc. That must have done the trick because it's running smoother than it ever has been OFF choke! Finally. Might need to tweak the sync just a teeny tiny bit but I'm very happy with the smoothness it has now!
It's crazy that this actually worked because I THOUGHT I cleaned them well enough last time...
I've been working on engines and carbs for years and these cv Mikunis are by far the biggest pain in the ass to clean
They can be problematic to get clean but especially if a bike has been sitting for long periods. Ultrasonic cleaners can be useful here but you've worked it out now the old fashioned way.
Glad you got 'er ripping again
Re: Idle and Throttle Sync Test
Posted: Mon Apr 03, 2023 6:40 pm
by Designer
Re: Idle and Throttle Sync Test
Posted: Wed Apr 12, 2023 3:27 pm
by Pio412
Quick question before I wrap up this thread... for my bike to run best when I'm adjusting the fuel screws my front is out 3.5 turns and my rear 2.5 out give or take. Is that front carb out too far? Is that an issue? Thanks.
Re: Idle and Throttle Sync Test
Posted: Thu Apr 13, 2023 2:39 pm
by Pio412
Nobody?
Re: Idle and Throttle Sync Test
Posted: Thu Apr 13, 2023 3:34 pm
by Herb
I don't know about the 800 but my 1400 is set at about 2 2/4 and 2 1/2 turns, the front is a little richer than the back.
Re: Idle and Throttle Sync Test
Posted: Thu Apr 13, 2023 3:47 pm
by Designer
Pio412 wrote: ↑Wed Apr 12, 2023 3:27 pm
Quick question before I wrap up this thread... for my bike to run best when I'm adjusting the fuel screws my front is out 3.5 turns and my rear 2.5 out give or take. Is that front carb out too far? Is that an issue? Thanks.
That's no too bad.
Did to take note of what Lechy posted about the Pilot Air Jets/Passages?
Also, when you deep cleaned the Carbs last, did you totally remove the Idle Adjustment Needle/"O" ring and blow out Exit Orifice (into the Carb Throat) extra well?
it is a very tiny hole.
Re: Idle and Throttle Sync Test
Posted: Thu Apr 13, 2023 4:46 pm
by Pio412
Designer wrote: ↑Thu Apr 13, 2023 3:47 pm
Pio412 wrote: ↑Wed Apr 12, 2023 3:27 pm
Quick question before I wrap up this thread... for my bike to run best when I'm adjusting the fuel screws my front is out 3.5 turns and my rear 2.5 out give or take. Is that front carb out too far? Is that an issue? Thanks.
That's no too bad.
Did to take note of what Lechy posted about the Pilot Air Jets/Passages?
Also, when you deep cleaned the Carbs last, did you totally remove the Idle Adjustment Needle/"O" ring and blow out Exit Orifice (into the Carb Throat) extra well?
it is a very tiny hole.
Yeah I removed everything when I clean the suckers. Made sure those were very clean.
I guess I'll just keep it what I have it at
Re: Idle and Throttle Sync Test
Posted: Thu Apr 13, 2023 5:17 pm
by hillsy v2
Pio412 wrote: ↑Thu Apr 13, 2023 4:46 pm
Yeah I removed everything when I clean the suckers. Made sure those were very clean.
I guess I'll just keep it what I have it at
You might still have a little crud in there. Maybe run a few tanks with Seafoam or MMO and see if it improves.
Re: Idle and Throttle Sync Test
Posted: Thu Apr 13, 2023 6:32 pm
by Designer
Pio412 wrote: ↑Thu Apr 13, 2023 4:46 pm
Designer wrote: ↑Thu Apr 13, 2023 3:47 pm
Pio412 wrote: ↑Wed Apr 12, 2023 3:27 pm
Quick question before I wrap up this thread... for my bike to run best when I'm adjusting the fuel screws my front is out 3.5 turns and my rear 2.5 out give or take. Is that front carb out too far? Is that an issue? Thanks.
That's no too bad.
Did to take note of what Lechy posted about the Pilot Air Jets/Passages?Also, when you deep cleaned the Carbs last, did you totally remove the Idle Adjustment Needle/"O" ring and blow out Exit Orifice (into the Carb Throat) extra well?
it is a very tiny hole.
Yeah I removed everything when I clean the suckers. Made sure those were very clean.I guess I'll just keep it what I have it at
My Experiences with Motorcycle Carb Rebuilding have been,... back 47 years ago,.... that even when
I thought I had done a superior cleansing of all the Ports/Passages/Jets/etc. the Carbs,...I discovered that even just the tiniest, little particle that evaded my efforts could mess things up.
May I suggest you run some Berrymans B12 through your Carbs?
Given the Hands-On Experience of one of our Board Members here;
Swilsonp51 wrote: ↑Thu Feb 23, 2023 9:35 pm
I ended up running seafoam in the carbs and letting it sit overnight started up the next day not really a noticeable difference, but then again some people do it multiple times before it works, anyway I thought I’d try Berrymans b12, I’ll be doggone if it didn’t make a difference,
His success, as he posted, shows that it might be A Better Suggestion,... at this point,... than the idea of using Seafoam or MMO.
Keep in mind,....they are quite different formulations, so there is a difference in how they can be of help to you.
Anyone who recommends them all as being are equal hasn't the experience we see above.
Re: Idle and Throttle Sync Test
Posted: Thu Apr 13, 2023 11:01 pm
by hillsy v2
Seafoam, Berrymans, MMO, whatever injector cleaner additive you like will probably help. You don't want to leave them sitting in the system for too long though - put some in a tank of fresh fuel and ride it dry (well, almost).
