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: online service manual for briggs model 28n707?


homefried1
06-29-2012, 11:37 AM
If you go to briggs and put this model number in, it comes back with no results. I need to know the valve clearances.

SonnyT
06-29-2012, 11:50 AM
check this link...
http://www.engine-valves.com/valve-adjustment/briggs-and-stratton/how-to-adjust-valves-on-briggs-and-stratton-model-number-28n707.html

RED-85-Z51
06-29-2012, 01:18 PM
0.005" cold, both valves.

Walt 2002
06-29-2012, 04:58 PM
I can send you a Service Manual for your engine along with some helpful hints on heading off a problem occurring with this engine.

Sorry, I don't agree with Red on this. While it will run, not as long before needing adjusted again as it would if set to correct clearance to begin with which is just as easy.

Address below, put in proper format and remind me, model number and what you want.

Walt Conner
wconner5 at frontier dot com

RED-85-Z51
06-29-2012, 05:09 PM
0.003"-0.005" intake and 0.005"-0.007" exhaust......0.005" is within spec for both.

Walt 2002
06-29-2012, 10:16 PM
0.003"-0.005" intake and 0.005"-0.007" exhaust......0.005" is within spec for both.

Sure is BUT the Intake Clearance is what causes the problem and .003" is farther away from causing a problem than .005" which is the max. spec. and no harder to do.

Walt Conner

RED-85-Z51
06-29-2012, 11:25 PM
Reminds me of the arguments we used to have on the kart racing forums over valve lash, one side said that there was a performance increase from lift by running 0.0005", versus those that ran a more conservative and safe 0.002". Effectively there was a net lift increase of 0.0015"...however, the end result was that in multiple back to back dyno runs, there was more HP increase from wrapping the header vs not wrapping the header, than valve lash, which had no discernable effect on power/performance.

In this situation, the question is, is there a benefit from using 2 different feeler gauges, and having to explain which rocker is intake and which is exhaust, for .002" less clearance, vs streamlining the process by using one feeler gauge and being within the recommended lash range on both valves...

Personally, in testing, Ive set both valve as close as 0.002" and had no ill effects on running/longevity, no valve burning, and it starts normally...but briggs says no closer than .005 on exhaust or .003" intake... Ive also had engines that started absolutely fine, but you could hear the rockers clacking, and I find .010 or more lash...and it starts perfectly.

My experience tells me that, valve train wear is a crapshoot on briggs OHV engines. Ive got engines out there with more than 300 hours on them, never had the valve covers off, without problems. And Ive had tractors come in with under 60 hours on them, with more than 0,020" lash,....

Ive got customers that I have to relash the engines every 2 years, they arent slipping, they just wont crank when it gets over like 0.010" lash, yet others will crank with .015" or more.

homefried1
06-30-2012, 12:50 PM
OK, talked to someone from briggs and after telling her how utterly worthless their website is, she clued me in that when they ask for model number, and only the model number, that actually means model number then a dash, followed by type number. THAT will get you the owners manual, but not the service manual. She then told me that the numbers are, as Red said, 3-5 and 5-7, so I set mine at 4 and 6 and made one heckuva difference. Motor spins much easier now and seems to have much more power.

Thanks to all for the replies.