needle shim
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- Posts: 107
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- Location: Modena (Italy)
needle shim
hello
does anyone know if this shim is present or necessary?
I don't have it and I got rich mixture...
[img]https://ibb.co/1z6j43q
does anyone know if this shim is present or necessary?
I don't have it and I got rich mixture...
[img]https://ibb.co/1z6j43q
- freeridenick
- Posts: 1578
- Joined: Fri May 23, 2014 1:30 pm
- Location: Derbyshire
Re: needle shim
The rear cylinder carb has a shim under the needle in the stock setup but not the front. It makes the needle slightly richer though so if you don't have it I'd suggest you look at the size of the main jets first.
I think that diagram is confusing as it looks like the shim sits on top of the head of the needle but that isn't right and wouldn't make any difference to the mixture anyway.
Have a read through the carb setup guide in the welcome in section.
viewtopic.php?f=31&t=14214
I think that diagram is confusing as it looks like the shim sits on top of the head of the needle but that isn't right and wouldn't make any difference to the mixture anyway.
Have a read through the carb setup guide in the welcome in section.
viewtopic.php?f=31&t=14214
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- Location: Modena (Italy)
Re: needle shim
thank for the reply,
maybe I misunderstood your post.
does it make any mixture difference to have or not this shim?
is the stock sequence spring-shim-needle the correct one?
because my carbs jet are 178 175 (45 middle jet) and still have rich mixture on the front cyl (fouled plug)
pilot screw are 1-1/4 out both
best regards
maybe I misunderstood your post.
does it make any mixture difference to have or not this shim?
is the stock sequence spring-shim-needle the correct one?
because my carbs jet are 178 175 (45 middle jet) and still have rich mixture on the front cyl (fouled plug)
pilot screw are 1-1/4 out both
best regards
- Pete.L
- Forum Health And Safety Officer
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- Joined: Fri Sep 26, 2003 5:09 pm
- Location: Bristol
Re: needle shim
Putting a shim under the needle will richen up the midrange. But if your bike was okay before and now is running rich the first thing I would look at is the choke cables. They have a tendency to stick occasionally and not seat correctly at the carb end.
Pete.l
Pete.l
My new ride is a bit of a Howler and I love to make her Squeal
Re: needle shim
The shim won't make enough if a difference to foul the plug.
There's something else going on.
There's something else going on.
It's not falling off, it's an upgrade opportunity.
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Re: needle shim
thank you,
could be the float level too high? anyone have an experience with this?
lele
could be the float level too high? anyone have an experience with this?
lele
Re: needle shim
Floats are not adjustable, and almost never fail.
Check your fuel tap diaphragm first.
Check your fuel tap diaphragm first.
It's not falling off, it's an upgrade opportunity.
- freeridenick
- Posts: 1578
- Joined: Fri May 23, 2014 1:30 pm
- Location: Derbyshire
Re: needle shim
The engine is standard and the needles too, right? What fouling do the plugs have? Are you sure it's excess fuel and not oil? If the engine is high mileage then worn valve seals would allow oil in and cause fouling. Worn rings too.
Re: needle shim
Only seen one set of bad floats in 23yrs, so yeah they are pretty reliable
What altitude are you at?
Loud pipes don't save lives, knowing how to ride your bike will save your life.
Re: needle shim
As for the shim in the first post, that goes in between the spring in the needle holder and the top of the needle.
Nice to have but not critical (though I would not run adjustable needles without it in place) and will not change the mixture
Nice to have but not critical (though I would not run adjustable needles without it in place) and will not change the mixture
Loud pipes don't save lives, knowing how to ride your bike will save your life.
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- Posts: 107
- Joined: Wed Oct 26, 2016 8:45 am
- Location: Modena (Italy)
Re: needle shim
engine is ok, I think it's fuel...i can clean the carbon deposit on the spark with my finger and it's not "oily"freeridenick wrote: ↑Wed Jan 06, 2021 6:52 pm The engine is standard and the needles too, right? What fouling do the plugs have? Are you sure it's excess fuel and not oil? If the engine is high mileage then worn valve seals would allow oil in and cause fouling. Worn rings too.
Last edited by tastethefloor on Thu Jan 07, 2021 7:50 am, edited 3 times in total.
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- Posts: 107
- Joined: Wed Oct 26, 2016 8:45 am
- Location: Modena (Italy)
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- Posts: 107
- Joined: Wed Oct 26, 2016 8:45 am
- Location: Modena (Italy)
Re: needle shim
my problem is strange because only the front cyl mixture is rich
is the standard pilot screw setting 1-1/4 out correct? maybe I have to lean it only on the front carb
is the standard pilot screw setting 1-1/4 out correct? maybe I have to lean it only on the front carb
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- Pete.L
- Forum Health And Safety Officer
- Posts: 7217
- Joined: Fri Sep 26, 2003 5:09 pm
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Re: needle shim
If it's not the front choke try blasting the pilot air hole through with some cleaner. You might have got a bit of muck caught in onetastethefloor wrote: ↑Thu Jan 07, 2021 7:15 am my problem is strange because only the front cyl mixture is rich
is the standard pilot screw setting 1-1/4 out correct? maybe I have to lean it only on the front carb
Pete.l
My new ride is a bit of a Howler and I love to make her Squeal