Valve gap questions for B&S 5 HP side valve engine ....

[Crazy Horse]

I've never been on the garden tractor forum here before I don't think so here goes.

I picked up an older 5 HP tiller with a B&S side valve engine. The valve gaps are about twice as large as what the recommended setting is .... I have about 0.020 for the exhaust and 0,010 for the intake. I notice that there is no real adjustment possible, at least not what I was expecting (with threaded adjustments). Sounds like I can increase the gap by grinding off the stems (if I had new valves), and if I understand it correctly the only way to reduce the gap on older valves is by grinding or lapping the valves in their seats.

Am I correct so far with this?

If this is the case, is it remotely possible that I could get this pair of valves back to the recommended gap by simple lapping? I have no idea how much lapping would be necessary to get this engine with the current valves back to the proper gap.

 

[Duner Wi]

In my opinion you will have a lot of time in lapping valves to get them to specifications. Valve grind would be my recommendation if you want to get them to spec.

 

[Crazy Horse]

In my opinion you will have a lot of time in lapping valves to get them to specifications. Valve grind would be my recommendation if you want to get them to spec.

I would imagine you are correct with that. Pretty primitive way of setting valve gaps either way .... and prone to a lot of very careful back and forth grinding and measuring. I suspect most people with those old engines just leave it as is and soldier on. They've prtobably never been checked or adjusted since brand new.

 

[Duner Wi]

I would imagine you are correct with that. Pretty primitive way of setting valve gaps either way .... and prone to a lot of very careful back and forth grinding and measuring. I suspect most people with those old engines just leave it as is and soldier on. They've prtobably never been checked or adjusted since brand new.

If the Briggs has the "Easy Start" feature and valves clearance is too great , it can be a struggle with rope recoil starter. Maybe 5 HP Briggs doesn't have "Easy Start",

 

[Mule Meat]

Use to be able to buy shims for B&S valve stems to adjust clearance on older engines. If I remember correctly. They are called Valve Protectors. I can't say if they are still available for B&S engines or not.

 

[Crazy Horse]

If the Briggs has the "Easy Start" feature and valves clearance it too great , it can be a struggle with rope recoil starter. Maybe 5 HP Briggs doesn't have "Easy Start",

This old girl has the easy start feature. I finally got it to start OK, I think it was losing prime but now works OK. An occasional backfire when starting and you gotta be careful holding that rubber rope grip. It cost me $20 so I'm not into it for big money yet ... I've read that the wide valve gap can be a cause of that backfiring. An

Use to be able to buy shims for B&S valve stems to adjust clearance on older engines. If I remember correctly. They are called Valve Protectors. I can't say if they are still available for B&S engines or not.

I can't find anything on a search .... where did you find that image you posted? Thanks ....

 

[Duner Wi]

This old girl has the easy start feature. I finally got it to start OK, I think it was losing prime but now works OK. An occasional backfire when starting and you gotta be careful holding that rubber rope grip. It cost me $20 so I'm not into it for big money yet ... I've read that the wide valve gap can be a cause of that backfiring. An

I can't find anything on a search .... where did you find that image you posted? Thanks ....

I don't know where the photo originated from but official B&S website lists multiple choices with pictures. I call them lash caps not positive of official name.

 

[Mule Meat]

I can't find anything on a search .... where did you find that image you posted? Thanks ....

The image came from a site that sales Honda engine parts.

The shims are called Valve Tappet Shims or Lash Cap Shims.. And like I said. I do not know if they are still available for Briggs engine now days. The caps slipped over the tappets and if needed shims were placed inside of the caps to adjust valve lash. At one time a full set of caps could be gotten that had different thickness of bottoms in them and shims weren't always needed when using them. If additional shims were needed. They were placed inside of the cap.

You will just have to do a web search for Valve Tappet Shims to see if you can find them to fit the tappets used in Briggs engines.

 

[Crazy Horse]

The image came from a site that sales Honda engine parts.

The shims are called Valve Tappet Shims or Lash Cap Shims.. And like I said. I do not know if they are still available for Briggs engine now days. The caps slipped over the tappets and if needed shims were placed inside of the caps to adjust valve lash. At one time a full set of caps could be gotten that had different thickness of bottoms in them and shims weren't always needed when using them. If additional shims were needed. They were placed inside of the cap.

View attachment 150184


You will just have to do a web search for Valve Tappet Shims to see if you can find them to fit the tappets used in Briggs engines.

Here's one (literally ONE) .... I'm guessint this is what you are referring to. I'm not bothering with it, for an hours use once each spring, it'll have to survive on its own. Nice chatting with you .... thank goodness for cut and paste .... check out this we link ....... a guy might die before remembering this by memory recall ....

https://www.ebay.ca/itm/177840835181_trkparms=itmf%3D1%26aid%3D1110006%26rkt%3D4%26mech%3D1%26algv%3DSimVIDwebV4WithCtxRankerV1UnifiedFeaturesWithAuctionUnificationKatReco%26pmt%3D1%26amclksrc%3DITM%26sd%3D363391487386%26sid%3DAQALAAAAENRb6XLtp5VT6kWQ9tWT%2BLk%3D%26itm%3D177840835181%26noa%3D0%26plcampt%3D0%3A160272551015%26algo%3DHOMESPLICE.SIM%26brand%3DBriggs+%26+Stratton%26asc%3D305937%26ao%3D1%26rk%3D1%26pid%3D101875%26b%3D1%26mehot%3Dnone%26lsid%3D0%26meid%3D9f6eb416be344ae5a2db1fd25baff696%26pg%3D2332490&_trksid=p2332490.c101875.m1851&itmprp=cksum%3A1778408351819f6eb416be344ae5a2db1fd25baff696%7Cenc%3AAQALAAABQNcuE5wSiaWXUpZtpAuJty4GYCq%252BLEH%252FN8HXnEhWX0xwkDW1uDN51f72s7GsFOUQ9WFGrCI8AiSbyE6tacE%252FxpPzcbI6%252Bfuy9WmqzFcws0MbCMk8eQBwhR%252FORk9PIxJE74SwawRiuw8WlDTX1N6sNzlVHuH%252FoeZq38dS9ft5Hl1E%252Boidn5QqUApVCZoUV%252BpHfyU6ttw%252F6e%252Fo1EAkPV7zL%252FmJDMrEkTv3RWGCfGqMgho4fEhicMzvaZe0V%252FnVOUDvYN5MCCr0dWDsq%252BpAhzMS%252FrIjK%252BWtmJWMRgzK1nQw%252FV8rq%252Famjn%252BrJ92%252Bn6HZ1ucOIkxYlaxInKx%252F98CD%252BJAKyKqswA59aPx%252Bi3FFZpOT6WFCa8o8o9CKrGsqBXNVWkPVBWkS%252BrwqDCDwBTku7ibFk4J2bjOeDoK4lngdUySmJ4wn%7Campid%3APL_CLK%7Cclp%3A2332490&itmmeta=01KQG2N24B9XDZRKN0F3BAAPJM

 

[Crazy Horse]

Here's one (literally ONE) .... I'm guessint this is what you are referring to. I'm not bothering with it, for an hours use once each spring, it'll have to survive on its own. Nice chatting with you .... thank goodness for cut and paste .... check out this we link ....... a guy might die before remembering this by memory recall ....

https://www.ebay.ca/itm/177840835181_trkparms=itmf%3D1%26aid%3D1110006%26rkt%3D4%26mech%3D1%26algv%3DSimVIDwebV4WithCtxRankerV1UnifiedFeaturesWithAuctionUnificationKatReco%26pmt%3D1%26amclksrc%3DITM%26sd%3D363391487386%26sid%3DAQALAAAAENRb6XLtp5VT6kWQ9tWT%2BLk%3D%26itm%3D177840835181%26noa%3D0%26plcampt%3D0%3A160272551015%26algo%3DHOMESPLICE.SIM%26brand%3DBriggs+%26+Stratton%26asc%3D305937%26ao%3D1%26rk%3D1%26pid%3D101875%26b%3D1%26mehot%3Dnone%26lsid%3D0%26meid%3D9f6eb416be344ae5a2db1fd25baff696%26pg%3D2332490&_trksid=p2332490.c101875.m1851&itmprp=cksum%3A1778408351819f6eb416be344ae5a2db1fd25baff696%7Cenc%3AAQALAAABQNcuE5wSiaWXUpZtpAuJty4GYCq%252BLEH%252FN8HXnEhWX0xwkDW1uDN51f72s7GsFOUQ9WFGrCI8AiSbyE6tacE%252FxpPzcbI6%252Bfuy9WmqzFcws0MbCMk8eQBwhR%252FORk9PIxJE74SwawRiuw8WlDTX1N6sNzlVHuH%252FoeZq38dS9ft5Hl1E%252Boidn5QqUApVCZoUV%252BpHfyU6ttw%252F6e%252Fo1EAkPV7zL%252FmJDMrEkTv3RWGCfGqMgho4fEhicMzvaZe0V%252FnVOUDvYN5MCCr0dWDsq%252BpAhzMS%252FrIjK%252BWtmJWMRgzK1nQw%252FV8rq%252Famjn%252BrJ92%252Bn6HZ1ucOIkxYlaxInKx%252F98CD%252BJAKyKqswA59aPx%252Bi3FFZpOT6WFCa8o8o9CKrGsqBXNVWkPVBWkS%252BrwqDCDwBTku7ibFk4J2bjOeDoK4lngdUySmJ4wn%7Campid%3APL_CLK%7Cclp%3A2332490&itmmeta=01KQG2N24B9XDZRKN0F3BAAPJM

Looks like it didn't work, will try once more .... https://www.ebay.ca/itm/17784083518...lp:2510209&itmmeta=01KQG2XSJZXN099Q9WAE7RE5X9

 

[Crazy Horse]

Here's an image ...

 

[Mule Meat]

Lash Cap Shims

Lash Cap Shims

www.precisionshims.com.au

 

[T.R.K.]

That Briggs part looks like the valve caps for the single cylinder overhead valve B/S engines. What that part does is make it possible for the valve to rotate when it is open. And in those overhead valve engines, the valve keepers will come out of the valve retainer if the caps are not present. (Found out the hard way.) On those overhead valve engines, the valves actually adjust with a screw and locknut in the rocker arm.

I also think it would be very difficult to get them into place on the valve stems on a 'side valve' engine.

My sugestion is to find someone who can grind the valves. It probably wouldn't take much ground from the valve face to take .014-.016 off the valve stem clearance. Then lap them into the seat. After they are lapped into the seats, adjust the valve clearance if you need to.

 

[Mule Meat]

I also think it would be very difficult to get them into place on the valve stems on a 'side valve' engine.

Valve lash shims do not go on the valves when using them on flat head engines such as B&S.
They fit over the tappets.
You had a table to go by to find the correct shim needed. Example of one for a Kawasaki Ninja motorcycle.