84 250R running rich

[hdd]

84 250R running rich haven't pulled carb yet to see what jets are in it but what else to look for it smells rich out if exhaust. I bought a carb rebuild kit for it

[Jmoozy27]

Have you checked your plug? White is lean, dark is rich, brown is good.

[barnett468]

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I would start by doing the following:

If the gas is old or yellow at all, change it . . Yellow gas is either oil or contaminated by rust in the tank or both.

Check the float level . . If it is excessively high, it can cause a rich or flooding condition.

..................Here's an example of it a little too high . . It should be just below the solid black line in your case . . If it is at the dotted line, it will still not cause a problem even though it is just a little high . . If if is above the dotted line, I would definitely fix it by bending the small metal tab slightly that depresses the needle, slightly upward toward the top of the carb.

If the float is plastic, it requires heat to bend it, and this should only be done by someone whom is very experienced, otherwise you might end up with a puddle of melted plastic which will no longer fit very well.

.................................http://ww2.justanswer.com/uploads/motoforge/2010-08-01_013312_Float_level_adjustment.jpg


............................................. Here's another in which you can see the is level way too low.


........................................http://www.bbburma.net/FujiFotos/FloatHeight/DSCF2434.jpg[/QUOTE]



If it stutters/burbles even the tiniest bit when you accelerate, it is rich somewhere . . If it simply hesitates as if it is out of gas, it is lean.

Post a photo of the plug . . The plug on the right is shiny which means it is wet which means its oily . . It is possibly rich too but its hard to tell because of black deposits from the oil . . This engine should be repaired . . The middle plug is perfect . . The left plug is lean.

..............http://i.imgur.com/eCSbd.jpg

...............http://www.4secondsflat.com/Plug-2.jpg


This plug is bone dry so the black means it is rice . . If both the threads and the porcelain is black, i would start by reducing the main jet size first . . In the case of a plug that has extremely heavy deposits like this, I would go down 3 sizes on the main because just one will not be nearly enough and two will likely no be enough . . Four would be too much.

http://www.dansmc.com/spcarbon.jpg

[hdd]

I really appreciate your comments and I will work on it this weekend my plug looks like the middle one just a little browner defiantly not like the others. I smells rich to me and kind of not winding out good until you get to third gear.
http://youtu.be/za-4pV3VxuY

[briano]

It's nice to see you wear a helmet in your videos

[barnett468]

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I really appreciate your comments and I will work on it this weekend my plug looks like the middle one just a little browner defiantly not like the others. I smells rich to me and kind of not winding out good until you get to third gear.

ok, the fact that you disappeared after you took off doesn't give us much to go on, however, it definitely missed at least 3 times as soon as you made your second shift . . read my previous post . . if it stutters/burbles when accelerating, it is likely rich . . it definitely stuttered, therefore it is likely rich . . if the gas level is ok, try 2 sizes down on the main jet and do the same test . . if the miss is gone, your main jet is perfect . . if the miss is still there, i think it might be another problem.

install a new plug so you can look at the color.

your spark plug color suggests your jetting is really close.

what oil are you using?

what ratio is it?

what is your elevation?

[barnett468]

I really appreciate your comments and I will work on it this weekend my plug looks like the middle one just a little browner defiantly not like the others. I smells rich to me and kind of not winding out good until you get to third gear.

i just listened to it again and it didn't miss in first . . it missed a tiny bit in second and even more in third which definitely sounds like too big of a main jet to me.

[hdd]

Thank you will look at it this weekend and get back to you thank you for your help

[barnett468]

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Thank you will look at it this weekend and get back to you thank you for your help

xlnt . . keep us posted

PS - nice back yard and garage.

[hdd]

Elevation 650
20:1 ratio
Will have to check oil type when I get home

[hdd]

still running rich
ok changed plug, rebuilt carb,, checked float level. still mainly on low end sputters but once it warms up good and run for a little while, it runs through all gears strong and no sputtering. the plug looks dark tan and one thing I noticed is that the idle screw has to be turned in just about all the way for it to maintain idle on the carb slide. I bought a couple of smaller main jets to try when they come in but I am just lost on why it is not running correct with the stock ones. looking at changing reeds also

[yaegerb]

Try 32 or 36:1 oil ratio. 20:1 is too much oil in my opinion. Do his before you change jets and see if that helps.

[hdd]

the manual says 20:1 running less oil like you suggested will not hurt motor?

[yaegerb]

Not running 20:1 will not hurt the motor. The only time you would need an oil ratio that high is if you were running your bike, pinned in 5th for hours. Try 36:1, it will actually richen your fuel mixture.

[hdd]

ok tired everything suggested seems to be better but sputters through 1st and 2nd then seems to clear up and run. once I ride for about 5 minutes it runs good through all gears. it seems like once warmed up good it runs fine. but it still smells rich to me out of exhaust after I ride it hard then let it idle. I have bought 2 smaller main jets but does it seem like I might need to change the slow jet the main is a 150 and the slow is a 50.
thanks for all your help

[barnett468]

ok tired everything suggested seems to be better but sputters through 1st and 2nd then seems to clear up and run. once I ride for about 5 minutes it runs good through all gears. it seems like once warmed up good it runs fine. but it still smells rich to me out of exhaust after I ride it hard then let it idle. I have bought 2 smaller main jets but does it seem like I might need to change the slow jet the main is a 150 and the slow is a 50.
thanks for all your help


ok, exactly what was it you tried?

no, 20:1 will not hurt the engine as mentioned . . they used that ratio for a safety margin that is definitely unnecessary with the oils available today . . use 32:1.

the slow jet is not causing your problem because your problem is above where the slow jet has much affect.

reduce the main jet size as i suggested and report results but clean the plug or install a new one.
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[jerkin]

Couple things I haven't seen mentioned. First, clean your air filter, you can't jet properly without a clean air filter. Next do a leakdown test, you will never get the jetting right if your sucking air from somewhere. I haven't been here long enough to know for certain but I'm sure there are pictures of a leakdown tester here somewhere. Basically you pull your exhaust and plug it at the cylinder (rubber stopper with the screw to tighten it works well) then pull your carb and plug in your tester to pump the cylinder up with air, should hold 6 psi for a few minutes, if not you start spraying soapy water around looking for leaks (reed gasket, base gasket, head gasket, etc. can also be crank seals)

A tester is easy to make, mine is just a piece of pvc that fits in the intake and is capped at the other end. I put a tire valve in it to induce pressure and a low pressure gauge (15psi max) to monitor the pressure. Pump it up with a hand pump and watch the gauge. Once you have these things done you can buy a few new plugs and properly jet your carburetor. 20:1 was for the crap oil they had in the 80's, run something decent like Maxima at 32:1 and you'll be more than safe.

Jetting is all done by throttle position, idle to maybe 1/4 throttle is the pilot jet, 1/4-3/4 is the needle and 3/4 to wide open is the main (this is just close, there is some overlap). Pilot is easy, if it idles and the plug is wet when you shut it off your close. Getting close on the needle is easy also, throw it in 3rd gear and hold the throttle half way open, when it winds out as far as it will go stab the throttle, if you gain rpms it's close, if it was already wound tight you are lean, raise the needle one spot and try again. Main is a little tougher and you need some room. Install a new plug and run it down the road wide open for a minute or so, pull in the clutch and shut off the engine. When you come to a stop pull the plug and read it.

[hdd]

went down a size on the jet and new reeds runs like a champ. thanks for all the help. im currently rebuilding another engine for the 250r and confused on the bore size the piston say 50 on the top of it but when I check it with my calipers the bore says 70.21mm and piston 70.15 on the Wiseco site its says 70.50 for 50 over. any suggestions why the difference.

[barnett468]

went down a size on the jet and new reeds runs like a champ. thanks for all the help. im currently rebuilding another engine for the 250r and confused on the bore size the piston say 50 on the top of it but when I check it with my calipers the bore says 70.21mm and piston 70.15 on the Wiseco site its says 70.50 for 50 over. any suggestions why the difference.

xlnt.

ok, where are you measuring it . . you should measure it around 3/8" up from the bottom.

if your calipers are accurate, your piston is severely worn.

you can take a sheet of paper and fold it over 4 times so it is around 3/4" wide and 2" long, then stick 1" of it into the bottom of the barrel then try to install the piston and gently push it past the paper . . if it goes past the paper, the wear on the piston and/or bore is excessive.

if you can push a piston past a piece of paper that is only folded over once, it is a little loose.
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[hdd]

ok I have 2 84 250R's now one runs great after I changed from a 140 main jet to a 130 both has some sputter until I make a couple of runs then run great. the other one sputters a little more then once I run a little the sputter goes away. On the one running poor until it gets warmed up I am running a 128main jet, good compression I think its something with the carb. I have rebuilt the carb., new reeds, new plug and it looks good light brown but for it to idle I have to turn the idle screw all the way in.
http://youtu.be/nT6UjYVl4ZM (Running good)
http://youtu.be/iemLVS93Bsc (Running poor until it gets warmed up) towards the end you can see it running pretty good.