OutdoorKing Repair Forum Forums Collectors Corner Cylinder Scott Bonnar 45 idling too fast

I have a Scott Bonnar 45, model number 80202 that is a 17'. Other numbers on it are 0607 02 7704150.
The engine idles too fast but I can't seem to get it to idle slower. Any ideas?
PS. I am new to the forum and welcome any advice.
Thanks
Johnando

hi there johnando and a warm welcome could be a few things really , cable too tight ? idle screw not correct ? too lean at idle maybe ? gov' spring stretched ?

resident reel mower dude BB will assist you well and fast with your machines i'm sure . but a few photo's will help all to assist you mate and hope you get all the help you need here , just help us help you with a few pic's .

welcome and enjoy your time .... Dave

Hi johnando,

I feel that your governor spring is too tight or fowling on something and thus is causing the engine to idle way too fast.

I gather your engine is a Briggs and Stratton unit that was built on the 15th of April 1977.

Some close up photos of the carby area would be a massive help, also some generalised shots of the mower.

Cheers,
BB

G'day all,

It looks like johnando has posted a full set of Briggs 'magic numbers' there. I.e Model 80202 Type 0607-02 Code 7704150

So BB has given the manufacture date, and the Model No. says that it has a Pulsa-Jet carby.

But as BB says, we really do need some close-up pics of the carby area, as there are several linkage variations for that carby type, and this is the most likely problem area.

Thanks everyone for your help. I am going to try a new governor spring as this might be the trouble. Attempting now to loa


d up some pics.

Thanks for the pics, johnando. Very enlightening, as expected!

This looks like it could be a fairly simple fix - the idle speed adjustment screw is cranked way up.
This diagram should help.



The mixture screw ['needle valve'] may well need adjusting too - start with the mixture screw one and a half [anticlockwise] turns out from fully closed, then:




As the instructions say, minimum idle speed is 1750rpm, if you have any way of checking this.

The governor spring is the light one in the lower position, and doesn't seem to be damaged or misconnected, the most common problems.

The upper [throttle return] spring is an add-on, necessitated by the throttle cable used on your machine - Briggs engines are designed to use a throttle cable with a single strand inner, which can operate in both push and pull modes.

Thanks BB. Im going down to outdoor king to get a new governor spring. wish me luck.