XS 250 carb and tacho cable oil leak question

[miki]

Hi folks,
I am new here ,got me a 1981 ,xs250 model 1U5 few mont's ago.Have few questions about carbs and oil leak on tacho cable .First i took some pictures of carbs ,so are this correct for my xs 250?
I have hard time to make it running good,basically when i let go of throttle it take some time to respond,revs are still high for few more seconds. Also it is running lean (white -grey spark plugs) , so i have to turn out fuel screws for about 4 turns to get decent fuel mixture.Also it would not go faster then 90 kmh that is about 55 mph .
Carbs are cleaned so i wonder maybe this are not original for my bike?
Second question is about oil leak in cylinder head cover hole where tacho cable gets in.Is there suppose to be some o ring or seal?Thank's

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[NewHavenMike]

your bike looks like its in great shape and the engine components apear to be stock, so that is good.

There is a chance that the idle jet could be too small for the bike, thanks to more modern fuels. Lets say the idle jet is the proper size, having them set 4 turns out should make it very rich. This leads me to believe that you have an airleak somewhere. The carb boots are the usual culprit along with the vacuum take-off ports. If the boots have cracks, its a good idea to replace them.

Look at the service manuals here and make sure your floats are set to the right height.

 

[xschris]

xs250 used a 32mm mikuni carb. Check all the basic maintenance areas for the bike and go from there. I would guess a xs250 would top out at around 70mph anyways so your not too far off. Keeping the bike as stock as you can will help make things easier and usually perform overall its best.

 

[miki]

Thank you.I did measure carbs inlets and they are 32mm on intake side so i guess this is stock then.
I did try usual method for air leak at intake rubber boots with starter fluid spray but i did not get any signs of leak.I will try to find new rubber boots.
Does xs400 intake boots will fit to xs250? I know that they are 34mm but they are much easier to find here.
Also about question about oil leak at at tacho cable inlet, any tips?

 

[xschris]

The tach has a seal in the motor. You would need to remove the rocker cover and push out the tach drive to get it out to replace it. There are threads on this in the forum.

 

[NewHavenMike]

There could be air leaks at the throttle shaft bushings, this leak will produce a hanging idle and you will be chasing it endlessly trying to set the idle screw to get a good idle speed. It will make it nearly impossible to set and get it stable.

 

[miki]

Thanks.