Author Topic: A couple of "tune up" questions...  (Read 3419 times)

Offline K2-K6

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Re: A couple of "tune up" questions...
« Reply #30 on: September 15, 2023, 09:22:47 AM »
Wonder what they do with all those 1.6mm saved all around the world  ;D ;D

Offline McCabe-Thiele (Ted)

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Re: A couple of "tune up" questions...
« Reply #31 on: September 15, 2023, 09:31:10 AM »
Wonder what they do with all those 1.6mm saved all around the world  ;D ;D

Probably used to make MDF.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline K2-K6

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Re: A couple of "tune up" questions...
« Reply #32 on: September 15, 2023, 09:48:46 AM »
 ;D

Online Rozabikes Tim

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Re: A couple of "tune up" questions...
« Reply #33 on: September 15, 2023, 01:11:19 PM »
Wonder what they do with all those 1.6mm saved all around the world  ;D ;D

Probably used to make MDF.

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One day I'll have the time to restore it, not just talk and dream....

Offline Bryanj

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Re: A couple of "tune up" questions...
« Reply #34 on: September 15, 2023, 03:13:11 PM »
No you lot, thats the plinters in yer fingers!

Offline Mikep328

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Re: A couple of "tune up" questions...
« Reply #35 on: September 15, 2023, 05:03:26 PM »
Tomorrow, in hopes of eliminating that off-idle stutter,  I'll try turning the airscrews in another 1/8 turn and also replace the spark plugs.  I couldn't find non-resistor NGKs but did find non-resistor Densos.  I can't imagine new plugs will fix the stutter but I wanted to replace them anyway.

I have some other thoughts re stutter elimination but I'll wait to see how the above works first.


Offline Johnny4428

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Re: A couple of "tune up" questions...
« Reply #36 on: September 15, 2023, 08:33:17 PM »
That’s a good move on its own Mike, getting rid of NGK plugs and fitting Denso. To many fakes/faulty plugs about.
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Offline Mikep328

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Re: A couple of "tune up" questions...
« Reply #37 on: September 16, 2023, 02:49:22 PM »
New plugs/airscrew adjustment did nothing to reduce the stuttering.  I didn't take my timing light when I walked to the garage since I had checked the timing and it was spot on several weeks ago.  But what I want to do now is use the timing light to see if each cylinder is getting regular/consistent spark from the coils in that RPM range.  The coils/plug wires are new from DSS, installed in '22 per the receipts..  It also has a DSS electronic ignition installed at the same time.   I don't expect to find a problem with those items but I have had strange problems with aftermarket e-ignitions on motorcycles in the past...;) 

Offline McCabe-Thiele (Ted)

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Re: A couple of "tune up" questions...
« Reply #38 on: September 16, 2023, 03:01:56 PM »
New plugs/airscrew adjustment did nothing to reduce the stuttering.  I didn't take my timing light when I walked to the garage since I had checked the timing and it was spot on several weeks ago.  But what I want to do now is use the timing light to see if each cylinder is getting regular/consistent spark from the coils in that RPM range.  The coils/plug wires are new from DSS, installed in '22 per the receipts..  It also has a DSS electronic ignition installed at the same time.   I don't expect to find a problem with those items but I have had strange problems with aftermarket e-ignitions on motorcycles in the past...;)

Can you adjust both 1-4 & 2-3 on your system or is it just one adjustment?
On my Dyna I have both it took quite a while to get both spot on.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline Mikep328

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Re: A couple of "tune up" questions...
« Reply #39 on: September 16, 2023, 03:09:44 PM »
"Can you adjust both 1-4 & 2-3 on your system or is it just one adjustment?"

Just one adjustment.  The relationship between the timing of 1/4 and 2/3 cylinders is fixed.  TBH, and this might sound weird, I would have preferred that the bike had the OEM ignition system rather than an e-ignition.

Offline McCabe-Thiele (Ted)

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Re: A couple of "tune up" questions...
« Reply #40 on: September 16, 2023, 03:17:58 PM »
Might be worth checking both anyway to see if they match.

At the moment my 500 will retain points until I am happy with the way it runs - then I might fit the Electronic one I bought from Bryan.

There is a lot to be said for roadside fixes that points can accomodate. That said points were a pain on older cars.
« Last Edit: September 17, 2023, 08:50:24 AM by McCabe-Thiele (Ted) »
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline K2-K6

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Re: A couple of "tune up" questions...
« Reply #41 on: September 16, 2023, 05:51:54 PM »
Interesting to see if tge ignition check turns up anything unexpected. They are usually reliable though.

A thought, are you running on E 10 fuel  ? as that may influence your jetting and may push you up on needle position to regain parity.

Also can be worth a try as it's a quick-ish change, drop the plug gap to 23 thou to see if that has any response or verifiable shift in the effect you are getting.

Offline Mikep328

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Re: A couple of "tune up" questions...
« Reply #42 on: September 16, 2023, 08:47:41 PM »
Thanks, I changed the gap on the old plugs to .025" before replacing with the new plugs, which I gapped at .030."  There was no difference in operation.  After doing that I checked all the air mixture screws for the position they were in after "optimizing" them last week.  Cyls 2,3 and 4 were around 1 1/2 turns out.  But cyl 1 was only 1/2 turn out.   If the screw was bottomed, that cylinder would cut out completely but from about 1/2 turn and beyond there was no change in RPM or smoothness.  So despite disassembly/cleaning, it appears there is still some obstruction in that carb's idle circuit.  :(

Fuel is E10. 

Offline K2-K6

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Re: A couple of "tune up" questions...
« Reply #43 on: September 16, 2023, 09:22:46 PM »
Agree that the question mark over that single idle circuit is probably going to cause you more work  :-\

Hard to get an clear evaluation without containing that really, unfortunately.

E-10 has approx 10% more oxygen content. So 10% of 10% E gives roughly 1% increases in oxygen to make it run a small amount lean, in comparison to it's original factory setup.

With that in mind, and while the carbs are off, it could be valid to then lift needles in targeting this overall review of running competently.  Depends on your personal assessment of it though.

If that were to be run like that it would likely still be contained within an air screw tweak. Just that it'd fatten up the  mid to low response to help you out there.


Offline Mikep328

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Re: A couple of "tune up" questions...
« Reply #44 on: September 17, 2023, 06:04:34 AM »
Today I'm going to check the spark delivery on the 4 cylinders and also check/verify that the E-ignition timing of cyls 2 and 3 agree with the timing of 1 and 4.  Following that I guess I will pull the carbs.  We'll be out of town most of the week so probably won't get them back on the bike till next weekend. 

I admit there is a part of me that is thinking that since the bike runs great except for the stuttering in a rather narrow, low rpm range, why not just leave it alone?  But the major part of me says, "No, I can't deal with that!"




« Last Edit: September 17, 2023, 06:07:28 AM by Mikep328 »

 

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