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Old 02-11-2013, 02:04 AM   #1
xy500 OP
Joined: Aug 2011
Location: Australia, WA
Oddometer: 73
1985 xl250r carb issues

G'day guys, i'm looking for a bit of input from more experienced honda wrenchers, for my latest project.
A 1985 Honda XL250R RFVC dual carb setup.
The problem is the bike won't hold a steady idle, will hang up with a raised idle after accelerating/cruising. Is hard to start. And generally runs very rich.
The bike has no air box, just a couple of pod filters.
The carb seems to have multiple air leaks (tested for by spraying directed squirts of lithium grease), from the plastic caps above the slides, and from the air cut diaphragm plate area. I've done my best to seal the leaks to no avail. I've removed the air cut diaphragm and blanked it off to try stop it leaking vacuum as it was perforated.
Currently the carbs both have 110 jets, and a 35 pilot jet in an effort to lean it out at idle. The rich mixture is apparent from the spark plug and the black smoke the exhaust produces. I've redone the valve clearances, reset the spark plug lead in the cap - makes a fairly healthy blue spark. Carbs are spotless inside.
Bike sounds like it's 8 stroking at idle.

Any help would be greatly appreciated, i think it needs new carbs and i'm ready to burn this thing.
Experience is wasted on the old
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Old 02-13-2013, 04:46 PM   #2
Enjoying my last V8
fritzcoinc's Avatar
Joined: Apr 2008
Location: Cypress, Tx
Oddometer: 7,290
You might try posting this over in the XRL fourm. i am sure there are some folk with more experience than me.
I had a twin carb. XR 600 but not for long.
But in general:
Fix the leaks.
Next, it sounds like the cables do not have enough slack. Maybe the second carb is open at idel?
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Old 02-14-2013, 04:43 AM   #3
xy500 OP
Joined: Aug 2011
Location: Australia, WA
Oddometer: 73
Well, i didnt think anyone would reply.
Turns out the secondary float was bent, so secondary carb was overflowing. Runs awesome now.
Edit: actually not so awesome.
Experience is wasted on the old

xy500 screwed with this post 03-21-2013 at 06:42 AM
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