Author Topic: running really rough, desperate need of advice--- *Problem SOLVED!!*  (Read 17006 times)

0 Members and 1 Guest are viewing this topic.

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,000
  • WHAT?no gravy?
Re: running really rough, desperate need of advice =/
« Reply #25 on: December 08, 2013, 11:23:26 PM »
float heights are only wrong if they are way wrong,when your riding the fuel is sloshing around like a washing machine anyway,picture inside them over rough ground,going up or down hills and hard cornering,braking and hard accelleration,the fuel is all over the place inside!what numbers are on your jets?
« Last Edit: December 08, 2013, 11:25:15 PM by dave500 »

Offline Deltarider

  • Really Old Timer ...
  • *******
  • Posts: 8,121
  • ... but some animals are more equal than others.
Re: running really rough, desperate need of advice =/
« Reply #26 on: December 08, 2013, 11:58:13 PM »
You did check the towers that house the main jets for cracks, didn't you?
Are you sure all the 4 airscrews are the same? Describe them please: are they open, crossdrilled, pointed ends damaged?
CB500K2-ED Excel black
"There is enough for everyone's need but not enough for anybody's greed."

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,000
  • WHAT?no gravy?
Re: running really rough, desperate need of advice =/
« Reply #27 on: December 09, 2013, 12:01:12 AM »
blocked emulsion holes in the slow jets and or the air feed passage?

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #28 on: December 09, 2013, 08:46:49 AM »
float heights are only wrong if they are way wrong,when your riding the fuel is sloshing around like a washing machine anyway,picture inside them over rough ground,going up or down hills and hard cornering,braking and hard accelleration,the fuel is all over the place inside!what numbers are on your jets?

thanks Dave, it really makes sense. i was hoping its something as stupid as that, so i can just get on and enjoy the bike after months of rebuilding her...
I think that my next step is to pull the carbs off and open them up and have a lookey see inside to see whats potting....

You did check the towers that house the main jets for cracks, didn't you?
Are you sure all the 4 airscrews are the same? Describe them please: are they open, crossdrilled, pointed ends damaged?

i didnt even think of looking for cracks, im going to pull them off shortly and take a look.

The airscrews have a flat end to them, they are all in great condition. they are currently all at 2.75 turns out. i made a reference mark on the carb when they bottomed out (i didnt force them in, just lightly screwed them in). they are solid, so cross drilled holes or hollow.

blocked emulsion holes in the slow jets and or the air feed passage?

could one carb be causing this? i mean, they were thoroughly cleaned and and, how could all of them be blocked?

here is the thread i started, never really updated it. otherwise, i cleaned everything off properly, i used special watch-makers cleaning equipment to clean all the brass bits, they came out brand new looking and shiny. i emptied out the carbs float bowls yesterday and the fuel came out pretty clean, i mean, besides the tiny bits of contaminant that is found in all fuel. I am running the tank filter and one on each fuel tube from the petcock to the carbs...

http://forums.sohc4.net/index.php?topic=117658.0

as you can see from the thread, i wasnt going to take any shortcuts... but who know, there could have been bits stuck in them somewhere that became dislodged after the rebuild i guess...

Offline DustyRags

  • I'm not skilled, I'm just a
  • Hot Shot
  • ***
  • Posts: 720
  • Just try it and see what happens
Re: running really rough, desperate need of advice =/
« Reply #29 on: December 09, 2013, 02:40:10 PM »
Not much to contribute here, just in for the follow.
1976 CB550K- sold
2005 Kawasaki Vulcan 500- sold
2000 CB750 Nighthawk - sold
1975 XL350 - crashed
2004 Suzuki Vstrom 650 - sold

Offline lucky

  • Really Old Timer ...
  • *******
  • Posts: 6,717
Re: running really rough, desperate need of advice =/
« Reply #30 on: December 10, 2013, 07:00:46 AM »
If you do not have the stock air filter and stock air box It could be running lean
That is why it stumbles before 1/4 throttle if you give it quick throttle.
Is it backfiring too?

If you put the choke on and you CAN give it quick throttle, then there is your answer.

Try richening the mixture screws 1/4 turn.



Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #31 on: December 10, 2013, 08:23:43 AM »
If you do not have the stock air filter and stock air box It could be running lean
That is why it stumbles before 1/4 throttle if you give it quick throttle.
Is it backfiring too?

If you put the choke on and you CAN give it quick throttle, then there is your answer.

Try richening the mixture screws 1/4 turn.



no no, she is definitely running rich, very rich, you can smell its and see it. there is no backfiring whatsoever.

thats what i cant understand, its already nearly 3 turns out and still rich as hell.even with no filter material in my airbox. The timing is dead on now too. she runs perfectly fine after i throttle her into the higher rpm, she flies!

its mostly at low rpm range, and when i am basically coasting in gear. she jerks and battles to accelerate below 1/4 throttle, as soon as i open up past there, she goes like stink and bellow black rich unburnt fumes out the pipe.

like i said, i did find the carb to intake boots loose on a two of them, wonder if that could be causing the issue? i havent ridden her since the weekend, bad weather.

Its almost like one cylinder is not firing properly at low rpm under load and as soon as i gas it, problem gone. could the timing have been out and as soon as the advancer kicks in, she all of a sudden sorts herself out??



Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,000
  • WHAT?no gravy?
Re: running really rough, desperate need of advice =/
« Reply #32 on: December 10, 2013, 11:37:53 AM »
in your first picture the choke is on(lever up)do you run it this way?if so push the lever down(choke off).

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #33 on: December 10, 2013, 11:49:02 AM »
i always seem to put it like that once i park the bike after a ride, i have a phobia of something crawling in there hahaha ;D i barely have to use choke anyway, the bike runs super rich remember...

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,000
  • WHAT?no gravy?
Re: running really rough, desperate need of advice =/
« Reply #34 on: December 10, 2013, 11:58:59 AM »
ok you got those numbers off the jets yet?

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #35 on: December 10, 2013, 12:21:15 PM »
not yet Sir, I first want to go for a ride after i tightened up those boots between the carbs and intakes. Also, my timing is spot on now too.

I received my new D7EA's today (non resistor this time). Should i slap them in while testing the above or leave the fresh plugs for when i know the carbs are perfect?

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,000
  • WHAT?no gravy?
Re: running really rough, desperate need of advice =/
« Reply #36 on: December 10, 2013, 10:48:07 PM »
just fit the new plugs and ride it,dont spend too long warming up the engine,do a decent ride any from the city,i have it too good where i live,not a stop sign or light.

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #37 on: December 11, 2013, 01:46:28 AM »
Will do just that Dave  ;)

yeah, i just have city and more city....oh, and the beach like 100 metres from my house ;D

Offline calj737

  • Really Old Timer ...
  • *******
  • Posts: 21,018
  • I refuse...
Re: running really rough, desperate need of advice =/
« Reply #38 on: December 11, 2013, 04:44:02 AM »
Would you mind an off-the-wall idea: is it possible, that somehow your coils are misbehaving at lower RPMs and thus not "firing" correctly? Perhaps Two Tired could chime in on testing/trouble shooting that theory. After all, it seems you've done every reasonable fuel/carb adjustment and check-double check and have not yet exorcised your gremlins.

I am not an expert by any means, but often times an overlooked thought is the "last place we look" before finding our solutions.

I'm just saying... And if this idea is full of crap, then please disregard. You're obviously experienced and there are many providing good and sound advice. Just a different direction or culprit may be involved.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #39 on: December 16, 2013, 10:45:08 AM »
thanks Calj, i dont think my coils are acting up, i am getting a nice blue/purple spark at idle and when i give her a little rev.

Maybe my advancer is acting up? As per Hondaman's tips, maybe my advancer springs are a little weaker?

I have managed to get time to work on my bike again. On Xmas vacation, yay!

So i built a manometer, fitted restrictors and used ATF. It came out really sweet and works really well too! But my word, the slightest of adjustments makes a HUGE difference, even when it comes down to tightening the lock nuts! But anyway, when i first connected the manometer, number 3 shot up and 4 went right down. so it made sense why cylinder 4 was acting up. so i got them to sort of level out and took her for a spin, she rides a little better, but not as id hoped.

i also removed the float bowl vent tube between 2 and 3 carb, as i connected them together after the rebuild as its the way i found it. But it didnt effect the bikes performance at all.

I replaced the spark plugs with the new D7EA's and no change at all.

why am i still running rich? is it time for me to rip my carbs off and have a look at my slow jets? and recheck my float levels? my air screws are out 3 turns now...

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,000
  • WHAT?no gravy?
Re: running really rough, desperate need of advice =/
« Reply #40 on: December 16, 2013, 11:02:11 AM »
ok you got those numbers off the jets yet?

ok you got those numbers off the jets yet?



Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #41 on: December 16, 2013, 11:03:51 AM »
oh yeah, i know she is running rich low down because today while riding, i forgot the fuel tap off and she ran way better low down, no spluttering and jerking..... maybe i should time it and switch it on and off all the time :D

Offline LesterPiglet

  • Old Timer
  • ******
  • Posts: 4,046
  • 1977 CB550F2
Re: running really rough, desperate need of advice =/
« Reply #42 on: December 16, 2013, 11:05:21 AM »
I can see you Dave, don't worry.   ;)
'Then' and 'than' are completely different words and have completely different meanings. Same with 'of' and 'have'. Set and sit. There, their and they're. Draw and drawer. Could care less/couldn't care less. Bought/brought FFS.


Les Ross.            Certified by a Professional

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #43 on: December 16, 2013, 11:05:35 AM »
ok you got those numbers off the jets yet?

ok you got those numbers off the jets yet?

haha, no Dave, i will have them for you tomorrow. I am almost sure they are standard, but you never know what the PO's over the last 30 odd years have been doing! :o

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #44 on: December 16, 2013, 11:14:48 AM »
oh yes, i forgot to mention i removed the casting marks from the intake manifolds...


Offline fdbrat

  • Hot Shot
  • ***
  • Posts: 275
Re: running really rough, desperate need of advice =/
« Reply #45 on: December 16, 2013, 07:26:45 PM »
From what I've read... It's not good to smooth out the intake.
1975 CB750F
4-4, Dyna S and box
5 ohm coils / 5k ohm caps
In- .05 / Ex- .08

San Luis Obispo

Offline harisuluv

  • Master
  • *****
  • Posts: 2,009
Re: running really rough, desperate need of advice =/
« Reply #46 on: December 16, 2013, 09:13:26 PM »
No offense but I hear forumla throughout this entire thread:

Q:  Guys what should I do??
A:  Try in order A, B, then C.

Bru-tom:  Ok guys I tried X, Y, and Z, and I'm now over here starting on T, any ideas what I should do?

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #47 on: December 16, 2013, 10:06:53 PM »
From what I've read... It's not good to smooth out the intake.

its defo not smooth man, its still rough, made sure of that. i know that it is no good to have a very smooth intake runners.

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #48 on: December 16, 2013, 10:10:34 PM »
No offense but I hear forumla throughout this entire thread:

Q:  Guys what should I do??
A:  Try in order A, B, then C.

Bru-tom:  Ok guys I tried X, Y, and Z, and I'm now over here starting on T, any ideas what I should do?

i am truly sorry to those who have tried to help me. The thing is, is that with my airbox mod, i cannot remove the adapter i made without drilling pop rivets out which is a pain. so i wanted to try everything else first.

When i refurbed my carbs, i did everything to spec and and...so it was the last place i wanted to recheck. but i guess its time... sorry for the run-around everyone :-[

Offline Bru-tom

  • Hot Shot
  • ***
  • Posts: 517
Re: running really rough, desperate need of advice =/
« Reply #49 on: December 17, 2013, 12:10:14 AM »
ok you got those numbers off the jets yet?

ok you got those numbers off the jets yet?




ok, my mains are 98 and slows are all 38. they dont appear to be drilled or tampered with. the needle heights are all 2nd clip position from the top. could the needles of the main jets be worn out so much to cause this?

also, should the main jet be sealed off when the throttle is closed and the needle is up against it?
« Last Edit: December 17, 2013, 01:14:50 AM by Bru-tom »