[nicksorg]

Guys,
I can't get the 300 to go past 2800 RPM at full throttle. I followed the steps outlined in the service manual:

I adjusted the throttle arm. I then loosened the nut on the governor arm and made sure the shaft was rotated all the way towards the front of the motor. I then pulled the governor arm away from the carb as far as it would go and tightened the nut.
When I run the engine and move it WOT, the rpms hit about 2800 as displayed on my TinyTach. I can move the governor with my hand to get it to go higher. Its almost like the governor spring is too long. What am I missing?
Thanks
Nick

 

[ron_white]

Nick,

When you have the throttle lever at WOT, is the butterfly parallel with the carb bore ??

 

[nicksorg]

Ron,
With the motor off and I move the throttle lever to full, the butterfly is open and perpendicular to the bore.
Nick

 

[jdalchemist]

Nick,
At the 2800 rpm WOT, is the throttle cable arm touching the high-speed limiter screw (right side of the picture)?
Harold

 

[nicksorg]

Harold,
At WOT its not touching the high-speed limiter screw as its basically out of cable. However, when this happens the throttle lever on top of the carb is open as far as it can go.
Nick

 

[nicksorg]

I disconnected the throttle cable and was able to work the lever up to full speed. I don't think there is enough room to pull with the existing cable. If I get a new cable and shorten up the governor spring, I should be able to make more room for the throttle control to go from low to high speed on the dash.
Nick in CT

 

[nicksorg]

I bought a throttle cable and installed it. In order to get full range of the throttle cable, I tried shortening the governor spring and it was so brittle that it broke. I tried stretching it and making it work but it just wasn't right. I ordered a new spring today. Hopefully that will fix it.
Nick in CT

 

[nicksorg]

I picked up the new governor spring today. It fit perfectly. I started her up and now have full range of throttle. I tested her out with a few passes on the lawn. Under load the engine seemed to be over compensating. I adjusted the governor arm and it seemed to correct it.
Nick

 

[nicksorg]

Update. The engine was idling OK but was surging at higher RPM and would back-fire at shutdown. I put in a new condenser, and tightened the manifold bolts a little more. I also checked the timing again, and adjusted the carb from scratch, but this time I set high idle with throttle at WOT and under load. It is running awesome now and also not smoking any more either. Feels like its been a long haul, but worth it. Thanks to everyone on WFM for the help and support.
Nick in CT