wheelhorse 520 hc vacuum issues

[jerry750]

Hello, I have a 1988 wheelhorse 520 hc with a 60" deck. Tractor has the 20 hp onan that has roughly 830 hrs on it. When idling the vaccum pressure runs about 7 on the gauge the issue Im having is when tractor is under load (deck engaged) at full throttle the vacuum pressure drops to below 2 and since the fuel pump runs off the vacuum of the motor needless to say it coughs sputters and will not run right, so i guess my question is what or where is the most likely culprit to create a vacuum leak. any insight on this issue would be greatly appreciated.

 

[jerry750]

Just wanted to add that I have inspected the vacuum lines and all seem fine. Now I have read that the vacuum pressure is maintained in the throat of the carb, but I have this other issue, fuel seems to be pouring into the carb and I mean a vapor cloud coming out the top of the carb so could this be connected with the vacuum issue or is it a separate problem all together. I plan on pulling the carb and cleaning it and readjusting but am still not sure bout the vacuum issue. I would appreciate any suggestions or thoughts anyone has to offer. As you know I am a new member and have read and found answers to other issues i had questions about but would really like to see some response on this, I really dont want to take to the dealer unless its a last resort. Thanks.

 

[CHDinCT]

jerry750, I have a 520 also with the 20hp Onan with about 715 hours, but I'm not much of an engine mechanic and can't suggest any trouble shooting tips. But, if you don't get any responses here, there's a whole bunch of rabid WH owners over at Red Square.

http://www.wheelhorseforum.com/

 

[jerry750]

Thanks I will check that site out.