Carb Parts
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At Mikuni and Yamaha dealers it is out of stock and no longer available
Found a supplier, that has the specs, nearly equal the original spring I hope
While Im at it, what would you suggest to get for carburetor adjusting
for a "stock" 4BL that has no more known restricted parts?
main jets in 230,240,250? others?
which idle jets? -
Hi, I want to change the jets because I dont know whats in there at the moment
The whole bike was not used for 6 years, it startet after the third kick, but it was idleing at 5000 rpm and I couldnt get it down
and it was dying with too much gas-pull, also the gas was hanging a bit in the end positionWhat is the full range you mean?
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That might be possible.
I didnt check the airfilter before starting the long time sleeper
After opening the airbox I found the filter was crumbling apart
I could image that this was causing it, but wouldnt that mean less air instead?
Even after opening the carb and realising its not even slightly dirt in there Iam wondering what caused the high idle rpmmaybe carb itself leaking?
I have ultrasonic cleaned all the parts, will redo all screws, hoses and gaskets and check againWhats the correct main and idle jet, is 240 and 25 okay?
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wow! I wouldn’t mess with the jetting until you’ve found the cause of the high revving. A split in the inlet manifold would be first try...
How long have you had the bike? How long has it been high revving? Have YOU altered anything?
P.S. Full range just means all the different sizes. I’ve seen them being sold as a set...
P.P.S. What is your native language?... -
@SpookDog
going to stock jets is no messing around I think
the inlet looks okay
I bought it years ago, rode it for 2 month without anything unusual and put it to a six year sleep, till now.The idea of this start was to burn in the new exhaust paint, check if the cooling system that I partly redid was proof and get the motor warm for an oil change after
I let it run for ca 20 min till the cooling system was leaking on a hose
This run was with the 6+ years old crumbling airfilter, what I realised only later
im from ger
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@chris
Guden Tag then bud!
Going back to standard would be bestest, but if it was running good 6 years ago I’d leave it until you work out the problem with ticking over @ 5000rpm! Even having no filter wouldn’t cause it.
Have you removed all the filter bits and cleaned out the carb since finding it, are you sure the slide is closing fully? No cable catching on an adjuster?
I usually spray a bit of carb/brake cleaner around suspected areas while the bike ticks over. If there’s a leak it usually settles down to normal revs...
It really does sound like a big air leak between the casing and the carb... -
@SpookDog
Danke sehrAfter that I cleaned the airbox and put a new and oiled filter in there.
Then I opened the carb, 5 screws were done and had to be drilled out, was a 2 hour pain in the ass work, I will use better screws with hexagon drive soon
I wondered how clean the carb was inside
The housing parts etc. are now ultrasonic cleaned and the spare parts available are orderedDo the gaskets for the housing parts have to be oiled during assembly?
What would be the correct torque for the housing screws?
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Now in hindsight I remember the choke's nut was loose
I didn't pay any attention to that, maybe that could be the cause of the air leak you mentioned.**Do the gaskets for the housing parts have to be oiled/greased during assembly?
What would be the correct torque for the housing screws?**
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@SpookDog
Yes, precisely because it is difficult to estimate, I always use a torque wrench on my rides to tighten if possible and the values from the manufacturer are available
Mikuni manuals do not have this info apparentlyI guess 5nm would be max for the m4 screws, and about 3nm for the brass stuff, but official data would be nicer
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I found new informations, here are the essential tightening torques:
Float chamber screws: 2.0 Nm
Main jet: 2.0 Nm
Slide cover screws: 2.0Nm
Screw slide lever: 3.5Nm
Drain screw: 2.0Nmcarb housing gasket at https://www.gasketguru.co.uk/
Also i found the throttle-spring at http://www.motocarb.com/tm-parts.html
still looking for the nozzle assembly
can you allow to edit posts, then I could reformat opening post and edit this infos? could be nice for others also looking for parts and stuff
