OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk valve guide replacement on 8hp flathead

Hi guys

I have a 191707-2135-01 8hp motor that needs both valve seat and valve guides replaced in inlet side. Apart from buying the valve guide replacement tool (too $$$) is there another way to drill and inset the new guide. To take the old guide out I think I could tap and insert a bolt and pull it out but Im stuck on how ensure I insert the new one correctly. Is there someone close to Lilydale vic..that has the 5/16 tool I can borrow?

Aussie280

Hi guys

Is anyone able to sugesstion a solution for me?

All assistance is appreciated.

Regards

Aussie280

Having not done this to any briggs engine before I would take my advice lightly.

Removing it sounds fine by using your method outlined, but reinstalling I would dare say it would be very important to use the correct tool, the alloy block is very softand having installed press fit parts in an automotive profession before, things go horribly wrong quite often without the right tool/press.

Hi Joe

Sorry for the delayed response. I tend to agree with you. Does anyone in Melbourne area have the briggs valve sleave tool I can borrow? I'll probably only ever use it once/twice in my life so cant justify spending $100 on it.

Regards

Aussie280

Having never done this myself on a side-valve engine, including a Briggs, but with the manual to hand, I offer these comments.

Aussie, hopefully you intended to use a simple guide/reaction point on the valve seat to center your puller-screw and to give you something to pull against, so you can pull the old guide out, if the engine has a valve guide (they often don't, on the inlet side). On the OHV engines I have worked on the guide went all the way through and no such reaction point was required, but in this case you do need one. Here is the instruction from the manual:
"To remove factory or field installed guide bushings on
aluminum engines, rotate nut no. 19239 up to head of
19238 puller screw. Center washer on valve seat.
(Larger washer may be required on some model intake
seats.) Lubricate cutting surface of screw and inside of
guide bushings with Stanisol or kerosene. Insert screw
19238 thru washer 19240, centering washer on seat.
See Fig. 10. Use 3/4" socket to turn screw clockwise to
a depth of 1/4" (6.5 mm) or until bushing starts to turn -
and -STOP. While holding screw stationary, turn nut
down onto washer until bushing is free."


B&S does not recommend any guide or keeping-it-straight process beyond due care, for installing the replacement guide, and their guide driver is rudimentary: you could make one on a lathe in a few minutes. Also, they offer (optionally) pre-reamed valve guides to save you the cost of a special reamer. Here are the instructions:

"Installing Replacement Bushing 230655
Clean out all chips. Press in valve guide bushing,
230655, using bushing driver, 19204, until flush with top
of guide or until it bottoms. Fig. 9, Illus. 4. The bushing
230655 is finish reamed to size at the factory, no further
reaming is necessary, and a standard valve can be used.
NOTE: Cast iron engines use sintered (gray colored)
valve guide bushings. DO NOT REMOVE THESE
BUSHINGS. See reaming valve guide (230655 or
231218 bushing) to install service brass bushings.
CAUTION
Valve seating should be checked after bushing the
guide, and corrected if necessary by refacing the seat."



If you want to do this job to a racing standard instead of a B&S service standard, you might take a look at this:
http://reviews.ebay.com/ebaymotors/...-RACE-PERFORMANCE?ugid=10000000013545787