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Carb Advice


XR650-R
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I had just started her....just done another test with choke fully in..OFF and she still drinks fuel ?....any thoughts now you have read the book and seen the film :)

By the way she doesn't want to rev much either; if thats means anything ?....

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Will do another video tomorrow bit late and I get gassed out in the garage lol....any thoughts on why she won't rev ?

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How crazy is this....with the choke completly removed the bike actually runs pretty good ?.....just by stocking your finger over the casting...this makes no sense to me and is driving me crazy, why on earth would no choke present be better than with the choke fitted and not turned on ?.....I thought the choke worked by sucking fuel up the internal pipe and this fuel was then introduced into the fuel/air mixture to richen the mixture, when the choke is off....puched in the rubber end of the rd blocks the draw tube and stop this extra petrol....?. Please someone tell me I am not going mad and explain why the bike should work so well with no choke fitted and a finger over the hole ?....

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eh? choke uncscrewed from carb and finger over the hole = full choke

I know this is what is doing my head in.....friend who messes with his 2 stroke all the time but nows nowt about the DT said take the choke out, I said you don't understand if I take the choke out it will be like fully on....anyway just to prove him wrong I did and bugger me it runs a lot better and fuel usage is much better ?.....something somewere is wrong plain and simple....but what....

She even smoked a lot less without the choke ?

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Lets go back upto pcture of your carb,

The choke feedpipe is too short, to dip into the well ,[incarb bottom] so I think it aint drawing fuel WITH the choke removed, it be drawing air ,, :eusa_think:

your thought s Paul :rolleyes:

DSC06072.jpg

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Blackhat the short pipe goes into a longer sealed hole forming part of the carb bowl....

DSC06098.jpg

Does all look well on the main nozzle ?

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choke

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choke hole leading from short pipe, gets blocked by choke rods end seal when pushed in

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plan view

DSC06102.jpg

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john, yeah the tube is shorter but no worries because the vacuum will draw fuel up the tube in the bowl anyway provided the seal around the tube is intact.

Now this syringe...How do we know that the rate of descent isnt absolutely normal, I've never heard of anyone using it as a health check tool for an engine? and didnt blackhat say his 250 did the same, dont forget the syringe doesnt hold much fuel in it's small diameter.

Cant see anything wrong with this carb, it looks in v good condition to me.

What about the smoking, boy does that thing smoke!!! this could cause rough running as I think I said earlier. The RH crank seal may be fubared for all we know...does the smoke smell bad bad bad yuk...or a nice 2t oil smell? Take out the dipstick, can you smell petrol in the oil?

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Dip stick just got a nice film of clean oil on it, no petrol or even a wiff of it :).....running out of idea's as I type as you say all looks good it's got to be something dead simple just looking at me in the face but cannot think of anything....friend has a beat up DT175MX field bike in his garage will pop down tomorrow morning and borrow his carb....only thing missing I can find on mine is the air mixture spring but that won't matter at this stage. When I ran the bike earlier it sprayed grey crap out of the exhaust all over my XJR1300.....grrr never noticed till just, thats the problem with 4 bikes in a garage no sodden room !!!

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tell you what, get a jam jar with a little water in it, take the gearbox breather tube and put it beneath the water level and start the bike, look for bubbles or the water going down...that'll test the RH seal, It's an easy enough test to do and I'm not happy about the smoking just yet but it could be the smoke they all put out when cold...just seemed an awful lot in the vid

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What about it running better with choke removed, it should bog right away , unless stone cold,,?

Unless its pulling air down from top ,then no vacume to draw fuel up thru choke passage,

this would make it rev cleaner, :eusa_think:

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Stuck friends horrible earlier model carb on today been sitting in a damp garage for years, and she runs lovely.....only thing I have found is the pilot jet tip has broken off.....could this make the bike suck loads of fuel through and cause all my problems ?....never noticed it before but when I look at the end of the jet you can see an unclean face...looked online and it should have a plain section after the threads....mine stops just after the threads ?. Least I know it's the carb and not the motor ?

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