Oil pump setting

[Loosenuts]

I have almost completed a 1978 Exciter 440 restoration,and am trying to set the oil pump. Manual says I should have a gap of 25mm (.980) for some reason......I can only get the gap in the cable to .700 any ideas on what to look for or change to get it right. Complete fresh motor....don't want to take any chances. I did premix 1 gallon to start it and have bled the pump which is working correctly.....just not set right.

Thanks,

 

[Yamaha Nutz]

where are you measuring the gap ?

 

[Yamaha440]

To measure properly, you must pull the cable out of the adjuster and measure between the adjuster and cable sheath.

 

[Loosenuts]

I am measuring by pulling the cable out of the adjuster and measuring the gap with a caliper.

 

[Yamaha440]

Have you set the throttle free play and idle yet? The manual states that you should set the idle, then the free play, then the oil adjustment. Idle is 1500 RPM and throttle free play is .5-1 mm measured between the throttle flipper and throttle block. Then set the oil cable to spec.

 

[Loosenuts]

Yes I have set them too.....thinking it has to be inside the pump that is not allowing the cable to get the correct gap setting.

 

[Yamaha440]

Very possible. Try taking the cover off of the pump, it is held with 4 Phillips screws. If you need to take the pump off you will need to buy a new paper gasket from Yamaha, as the worm gear that comes from the pump drive is bathed in injector oil. When scraping the old gasket off, do so with the oil pump upside down, gasket side facing you. This is to prevent gasket material from entering the pump.

Also you may want to consider an impact screwdriver. Many times these screws are tight and their heads strip out. The impact screwdriver applies a sharp downward force with the rotational force every time you hit it with a hammer. I have never have stripped a screw with it, and there were some tight ones!

 

[Loosenuts]

Thanks for all the help and advice !! I have had the pump off and the cover off to install the NOS cable. I just cleaned it up, put the cable on lubed it and installed a new gasket. I did not change anything other than that. Just wondering if the stroke is off....or what would cause this too be so far off.

Thanks again.

 

[Yamaha440]

To check the minimum pump stroke rotate the engine if still on the engine, or rotate the worm wheel if it is off the engine. Do so until the plunger moves fully out from the oil pump body, this is under the pump cover. The measurement is taken between the raised boss of the adjust pulley and adjust plate. This should be .20-.25 mm. To adjust remove the lock nut on top of the assembly and the adjust plate. Add shims to adjust this thickness.

The adjust pulley looks like a washer/collar combo closest to the engine. The adjust plate is on the end of the assembly farthest from the motor. The measurement is taken between the collar potion of the adjust pulley and the adjust plate.

 

[Loosenuts]

Once again...Thank you!! In your opinion, do you think the setting that you are talking about in your last post could cause the cable to not get the correct gap?

 

[Yamaha440]

I don't think so, as it says nothing about the maximum pump stroke, just the minimum. It couldn't hurt to find out, you may be able to do it easily on the engine, provided you can get your screwdriver in there. It should be over oiling with a smaller gap. Is the adjuster or cable bracket damaged?

 

[Loosenuts]

The bracket looks good,and the cable is NOS the most I can get out of it is .860

 

[Yamaha440]

Whats the length of the threaded portion of the adjuster? I won't be able to compare it with my sled until this weekend, however.

 

[Loosenuts]

I will try to get that measurement and get back to you.