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Discussion Starter #1
Hello! I am new to the forum and am looking for a little help. I can't seem to find any info on the correct adjustment for the carb to oil pump cable on my Yamaha Excel III 340.
Any help would be greatly appreciated!!

Thanks in advance!!
 

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Discussion Starter #3
Not sure yet. I've only been running it on a jackstand. I just got it. The trip odometer says about 10 miles and its used about a quarter of a tank of oil. It also smokes heavy.
 

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WAY rich. I used a quarter tank in about a tank of gas. I thought mine was a little rich, but better to be rich than lean. Upper rod bearing went anyway from stress cracks. (probably had a rattling issue). I just parted it out because of it, not worth fixing, the crank bearing ate the debris. I have many parts if you want any. PM me for parts info.
 

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to adjust the oil pump, where the cable attaches to the carb there is an adjusting nut.

pull the pump open using the cable and measure how much cable is exposed between the adjuster nut and the cable housing.

a properly adjusted cable will show 25mm of cable between these two points.

throttle cable freeplay must be set prior to adjusting oil cable.
 

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Discussion Starter #6
to adjust the oil pump, where the cable attaches to the carb there is an adjusting nut.

pull the pump open using the cable and measure how much cable is exposed between the adjuster nut and the cable housing.

a properly adjusted cable will show 25mm of cable between these two points.

throttle cable freeplay must be set prior to adjusting oil cable.
Thanks to you guys for your help!!! Greatly appreciated!!
 

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I adjusted it to 25mm, but that is at the MAXIMUM adjustment. I ran it and fouled the plugs in 2 min.
ANY help on this is appreciated!!!
I consulted a very large Yamaha dealer and they don't even have anything on it.
It's a 1986 EC340K Excel III
Thanks again!!!!!!!
 

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you may have a few variables to deal with based on age of the machine.

first, perhaps the oil pump itself is in fail mode. it will open all the way up when it decides to go as a fail safe.

second on the list wold be condition of the cables as well as the adjustment on the throttle cable itself. if the throttle cable is out of adjustment, so will be the oil cable. if either is stretched due to age, you need to factor this as well.

third on my list would be the shim in the oil pump. seems as though back in those days you could add/delete a shim to increase/decrease the stroke of the pump arm. yours may be worn.

if you fouled the plugs at an idle, you can alter your warm up technique or try backing the pump cable to around 21mm. try this under the assumption your doing it at your own risk. by carefully playing with the cable adjustment and monitoring oil usage in ratio with fuel consumption, you can derive at your "happy" setting. this based on a properly calibrated pump.

if you cant seem to get a hold on the oil usage, your pump may be bad. has it been changed in the last 30+ years?
 

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You did adjust as the diagram in the attachment below says right?

NOTE: This diagram is for an Exciter 440 ('79)
 

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You did adjust as the diagram in the attachment below says right?

NOTE: This diagram is for an Exciter 440 ('79)
Thanks so much for your reply!

The cables are good.
At 25mm the adjuster has almost no threads left. It is maxed out. It doesn't seem correct.
If I back it off it runs good with no fouling.... It's getting to be time to ride and I don't want to fry the engine by running too lean...

Any thoughts?
 

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Ok.... adjusting the cable while running has no effect on performance. Now, it will load up one cylinder with oil when sitting. If I pull the one plug, it's soaked. The other cylinder is fine. The cylinder that loads up with oil is the one closest to the oil pump... I am assuming the pump is bad and am willing to switch to premix in the tank... Does anyone know the correct mixture? Also, do I have to remove the pump and install a plate, or can I just empty the resovoir and leave the pump installed?.... And one more thing, Can the carb perform properly with gas/oil mix, since it is not designed for it.
Any help is greatly appreciated!!!!
 

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Hello! I am new to the forum and am looking for a little help. I can't seem to find any info on the correct adjustment for the carb to oil pump cable on my Yamaha Excel III 340.
Any help would be greatly appreciated!!

Thanks in advance!!
Here you go this helped me alot lol i have a 86 excel 340 this is owner's manual
 

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This just to give you a starting point.
To fine tune it you must take it out and ride it.Measure how much exactly you used and do the math!
A qt of oil to 12.5 gal of gas is 50-1 and with todays syn oil that is more than enough!
To give less oil shorten to give more oil lengthen
I am at about 60-1 with Amzoil in my Big Pantera,
 
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