running waaaay rich

[winkel02]

Gday all,

I'm new to the XS and new to motorcycling in general, so I'm hoping someone can help.

I have an '81 RH model (Australian). My problem is it is currently running hugely rich. Getting about 8-10L/100km (think that's 20-25mpg or thereabouts) and spark plugs are getting black within a day of use (not wet or oily, dry carbon).

My biggest issue, aside from the cost of fuel, is that from just off idle to around 4ooorpm the bike really struggles - misfiring and generally sounding like it's drowing in fuel...after that it takes off (as gets enough air to run better i guess).

I've had a mechanic check the carbs out and stock main jets for this is 110, but it currently has 102.5's. Mechanic says emulsion tubes and needle are worn, but I didn't think they could cause this big a problem? He didn't pick up any other issues, but he only had the carbs (bike was off the rd at the time).

Spark is good, air filter is good, so this leaves something in the carbs, and I was hoping for a different diagnosis to the emulsion tubes/needle.

Any ideas for a fix for this? I ask, because I've been quoted $700 for parts alone to get new emulsion tubes and needles.

Cheers

[pggg]

Wink, first off - don't ever go anywhere near that mechanic ever again. What he told you is bordering on a criminal offence! This rich problem is more than likely caused by badly adjusted floats. I've seen carbs with their floats adjusted by 'eye' eg - "about there will do" Probably what's happened somewhere along the line. Also, someone probably put in 102.5's to try and compensate. Tweak the float levels to around the 23mm mark very very accurately - then see how you go. You'll most likely need to go back to stock jets. Includes the pilot jets too. Who knows what size they are at the moment? Plonk the carb set on the kitchen table and strip 'em at your leisure. Ignore the wife's nagging.

[xj11john]

Good answer!

Pggg, I love your responce, could'nt have said it better, esp. the part about the carbs on the kitchen table and ignore the wife's nagging, What a hoot!

[winkel02]

hahaha excellent, thanks so much for the tips. This forum is so useful, it's a shame I don't have a local one in Aus.

Almost makes me feel like getting married just so I can ignore the nagging to work on my bike.

[Parr8hed]

Plonk the carb set on the kitchen table and strip 'em at your leisure. Ignore the wife's nagging.

I love it!!!! Sounds just like the first time that I went into my carbs!!!!

[LoHo]

Or plonk 'em in the garage to avoid her help in "picking up after yourself." "I don't know which thingy went with which...they're all the same, right?"

[TopCatGr58]

Hey there Winkel02,

As you may have noticed, PGGG is just across the beach front from you, but if you'll do a search in the Idle Chat Forum for Australia, you'll find several other fellow Ozzies there, maybe someone will be close to you?

Also, since your stock main jets are wrong, most likely the P.O. or misguided mechanic may have used the dreaded K&L jet kits, and they are notorious for being sized wrong!!!! Get some OEM Mikuni Pilot jets, along with the 110 mains, and set your floats right, turn your pilot screws out 1 1/2 turns out from gentle seat, and it should be good to start!

What type of intake filters are you running? There are some pod filters with too thick/wide a lip that interferes with the air jets on the inlet bell causing a too rich condition also. Good Luck.
G'day! T.C.

[Winterhawk]

I agree with TopCat.

Just because the pilot jets say 45 or whatever size you need doesn't mean the opening is sized right.

I think your pilot jets are the wrong size. Seen it happen over and over again from lesser types of shops trying to work on XS1100's. Try OEM jets