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Carbs

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Skid Mark
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Carbs

#1 PostAuthor: Skid Mark » Wed Mar 02, 2022 5:57 pm

Hi again all,
I got the 1000r running, which is great, however its throwing out more smoke than a Russia frigate and is idling at between 4-7.5K.
I'm think its carburation.
I sent the carbs away to be overhaled and the came back looking like new, however it only occured to me after reading a few previous posts that no consideration was given to the neta 4/1 exhaust and the K&N pods that are on the bike.
The main jet is #127.5, Seat #2.5, slow jet is #37.5. circlip on needle is second grove from the bottom.
Are these any way near what you would expect on this set up?
I checked all the obvious such as cable routing, the throttle adjusting screw is on the lowest setting.
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Re: Carbs

#2 PostAuthor: z1bman » Wed Mar 02, 2022 6:18 pm

remove the carbs make sure the idle screw is backed of & see if the throttle butterflies are open if they are you need to make sure they are fully closed by altering the adjustment/ ballance screws

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Re: Carbs

#3 PostAuthor: Skid Mark » Wed Mar 02, 2022 9:33 pm

Hi Z1Bman,
They are in the closed position, however I can seen a very small crescent of light maybe 1-1.5mm at the bottom of each, is this an issue?

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Re: Carbs

#4 PostAuthor: z1bman » Wed Mar 02, 2022 10:04 pm

yes with the idle screw backed rite of & slack in the cables you should not be able to see any light coming through the butterflies

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Re: Carbs

#5 PostAuthor: Skid Mark » Thu Mar 03, 2022 6:59 pm

Thanks for the advice.
I'll try that and let you know.
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Re: Carbs

#6 PostAuthor: Skid Mark » Fri Mar 04, 2022 4:37 pm

z1bman wrote:yes with the idle screw backed rite of & slack in the cables you should not be able to see any light coming through the butterflies

I over estimated the gap at the top and the bottom. I can barely get the tip of a 0.10 feeler gauge under the butterfly. Although there is a bit of light there is little room under or above any of them. I slackend of the balance screws but the butterfly valves appear to be closed fully. I also lossened the two philips screws on one valve to see if it would seat in better but it didn't budge
What next?
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Re: Carbs

#7 PostAuthor: z1bman » Fri Mar 04, 2022 8:08 pm

do they look like they have been removed? they have a taper on the edge & they may have been installed incorrectly

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Re: Carbs

#8 PostAuthor: Skid Mark » Fri Mar 04, 2022 8:45 pm

z1bman wrote:do they look like they have been removed? they have a taper on the edge & they may have been installed incorrectly

I think they were dismantled for cleaning, when I was trying to adjust them, one of the screws was a bit chewed so that would indicate someone was at atleast one of them. I didn't think to check for a bevel on the edge.
I'll have a look, working tomorrow so it will be next week.
Good shout, thanks for that.

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Re: Carbs

#9 PostAuthor: Al » Fri Mar 04, 2022 10:18 pm

Best i could find as i dont have CV's anymore. These are the same version as yours with the coasting enricheners.
Anything look odd about them or different from yours particularly the resting angle of the butterflys' operating arms when the butterfly valves are fully closed?

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Re: Carbs

#10 PostAuthor: Skid Mark » Fri Mar 04, 2022 10:58 pm

Al wrote:Best i could find as i dont have CV's anymore. These are the same version as yours with the coasting enricheners.
Anything look odd about them or different from yours particularly the resting angle of the butterflys' operating arms when the butterfly valves are fully closed?


Hi Al,
Here are pictures before and after. I can't see any obvious difference with the picture you posted. However I did note when rumaging to post these that while the circlip is fitted to the second last hole on the needle now, it was on the third last hole before cleaning. I never fettled with carbs before other than idle speed or cleaning after dirt. The high revs and white smoke had me thinking that jetting was way off, but TBH I haven't a clue. While the correct groove would make a difference could it be this obvious? Am I correct in thinking that raising the circlip would drop the needle, reducing fuel??
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Re: Carbs

#11 PostAuthor: Al » Sat Mar 05, 2022 12:15 pm

Manual says; circlip on second groove from the top for non USA bikes, but this wont explain youre issues as one clip movement might make a few hundred revs change at best and is a mixture thing not a revs thing at well above idle.
With the idle speed thumb screw and throttle cable removed, operating the throttle butterflys' should have a smart snap back to fully closed and be repeatable. I did have to up the tension on the return springs on mine at one point to stop surging. If the throttle return springs are very weak or incorrectly set, it may be possible for the engines' vacuum to open them further.
Looking at the last two pics you posted its clear that someone has had a fiddle at some point as the float bowls were on left to right backwards before you sent them away.
It may be an optical illusion but from memory; when you are adjusting the balance screws, i seem to remember getting 'straight on ~ in line' access to the screw slots with a screwdriver from above with the carbs mounted to the head. Yours look to be canted backward and were like it before you sent them away. It suggests that something is not right there but was like it before hand.
As far as revving / surging to 7.5K is concerned, it could probably only partly be explained by that amount of throttle opening and may be that something else is acting in concert. I hate to say it but it may be a valve timing issue as well :(.
Is the white smoke actually smoke as in un-burnt oil or is it extreme condensation, WD 40, fuel additive / stabiliser, water in the exhaust, other?
Personally, for set-up and testing, i would remove the balance pipe between carbs 1 and 4 and leave the pod filters off. It wont run correctly without the filters (nor with them in my opinion) but they have been known to obscure the fine jet inlets in the carb mouths in some instances.

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Re: Carbs

#12 PostAuthor: Al » Sat Mar 05, 2022 12:25 pm

Looking at the carb bodies; they do not look unifrormly clean enough to suggest that they have been vapour blasted. They look more like US cleaned.
I did both to mine and found that the vapour blasting media blocked off many of the internal drillings and in an attempt to clean that out effectively, ultra-sonic cleaning removed the sealer from the outer surfaces of the tiny ball bearings that are pressed in from the outside to blank off where two seperate drilling are used to change the direction of fuel or air flow internally. I replaced the sealer with araldite blobs initially but finally used the tiniest drops of superglue 3, using just enough to seal from the outside without bypassing the bearings and blocking the passageways that lay behind them!!
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Re: Carbs

#13 PostAuthor: Skid Mark » Sun Mar 06, 2022 12:25 am

Hi Al,
A lot to take in there.
Al wrote:Manual says; circlip on second groove from the top for non USA bikes, but this wont explain youre issues as one clip movement might make a few hundred revs change at best and is a mixture thing not a revs thing at well above idle.AL

There are seven grooves on my needle, The previous setting was third from the bottom, They are now 2 from bottom, If the book says 2 from the top that is four grooves out?

Al wrote:With the idle speed thumb screw and throttle cable removed, operating the throttle butterflys' should have a smart snap back to fully closed and be repeatable. I did have to up the tension on the return springs on mine at one point to stop surging. If the throttle return springs are very weak or incorrectly set, it may be possible for the engines' vacuum to open them further. AL

I will check these on Monday but from memory the are pretty free and snap back.
Al wrote:Looking at the last two pics you posted its clear that someone has had a fiddle at some point as the float bowls were on left to right backwards before you sent them away.AL

I spotted this my self only when posting the photo's. There were a few items reassembled on this bike incorrectly, as I only found out after completely striping and re assembling.
Al wrote:It may be an optical illusion but from memory; when you are adjusting the balance screws, i seem to remember getting 'straight on ~ in line' access to the screw slots with a screwdriver from above with the carbs mounted to the head. Yours look to be canted backward and were like it before you sent them away. It suggests that something is not right there but was like it before hand. AL

It does appear that the butterflies are not closing fully. Does anyone know if the butterflies should be vertical in the closed position? At present and before I sent them off they were perhaps 10-15 deg off vertical in the closed position and showing light.
Al wrote:As far as revving / surging to 7.5K is concerned, it could probably only partly be explained by that amount of throttle opening and may be that something else is acting in concert. I hate to say it but it may be a valve timing issue as well :(.
Is the white smoke actually smoke as in un-burnt oil or is it extreme condensation, WD 40, fuel additive / stabiliser, water in the exhaust, other? AL

I hope it isn't vave timing! :eek The Smoke is white rather than blue(I think) and lots of it. It is smoke not condensation. I did think initally it may have been from oil perhaps in the exhaust, but there is a lot of it and I didn't want to keep the bike running at high revs straight from cold. I did take a picture of exhause I'll put up tomorrow. Not WD40 or additive BTW.
Al wrote:Personally, for set-up and testing, i would remove the balance pipe between carbs 1 and 4 and leave the pod filters off. It wont run correctly without the filters (nor with them in my opinion) but they have been known to obscure the fine jet inlets in the carb mouths in some instances.AL

I will try removing the balance and filter, I will be keeping an eye out for a J or R airbox anyway.

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Re: Carbs

#14 PostAuthor: Skid Mark » Sun Mar 06, 2022 12:28 am

Al wrote:Looking at the carb bodies; they do not look unifrormly clean enough to suggest that they have been vapour blasted. They look more like US cleaned.
I did both to mine and found that the vapour blasting media blocked off many of the internal drillings and in an attempt to clean that out effectively, ultra-sonic cleaning removed the sealer from the outer surfaces of the tiny ball bearings that are pressed in from the outside to blank off where two seperate drilling are used to change the direction of fuel or air flow internally. I replaced the sealer with araldite blobs initially but finally used the tiniest drops of superglue 3, using just enough to seal from the outside without bypassing the bearings and blocking the passageways that lay behind them!!
AL

My understanding is they were Ultra sonic cleaned. I didn't pay particular attention to the ball bearing seals etc. I'll check these out also TBS.
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Re: Carbs

#15 PostAuthor: Al » Sun Mar 06, 2022 11:46 am

I may have alarmed you un-necessarily because i assumed that the jet needles had 5 grooves as mine did. would be worth checking if yours are the correct ones though.
The butterfly's wont close to vertical but they should close completely.
Click to zoom.

Z1000R carbs.png


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