Updated 4:40 pm - Clarifying Question - Re: Briggs & Straton 28M707 1162-E1; L Head - valve seats and clearances

[heyinway]

To remove seat...run a bit of mig or stick weld around the inner diameter. It will shrink and fall out. Of course you need a new replacement then

 

[Adevo]

Apologies once again:
28M707-1162-E1 Code: 980325ZA

Hmmm still not giving all the engine info but I took a look at 1 of 200+ 28M707 and here is it valve clearances for the L-head.

View attachment 67021

The valve clearances you are quoting are for an OHV engine not a L-head.

Now if can pick which of the following is your engine would help looking it up.
View attachment 67022

I got the following specs

Hmmm still not giving all the engine info but I took a look at 1 of 200+ 28M707 and here is it valve clearances for the L-head.

View attachment 67021

The valve clearances you are quoting are for an OHV engine not a L-head.

Now if can pick which of the following is your engine would help looking it up.
View attachment 67022

 

[Adevo]

To remove seat...run a bit of mig or stick weld around the inner diameter. It will shrink and fall out. Of course you need a new replacement then

thanks for the feedback, however I don't have a welder

any other suggestions?

 

[Adevo]

I reviewed my findings and it seems that the valve specs are as I stated earlier:
Intake: .003 - .005 in
Exhaust: .005 - .007 in

My current clearances are:
Intake: .006 - .007
Exhaust: no clearance

 

[StarTech]

I reviewed my findings and it seems that the valve specs are as I stated earlier:
Intake: .003 - .005 in
Exhaust: .005 - .007 in

My current clearances are:
Intake: .006 - .007
Exhaust: no clearance

Will you get off those specs as I am personally pulling the info from the dealer's Briggs' Power Portal.
Okay the specs for this 28M707-1162-E1 engine are the same as I previous quoted from Briggs Power Portal.

This is the last time I will repeat myself.

Valve Seat PNs.

And here is the instructions on valve seats from the service manual.

Personally I would leave the exhaust seat alone and just adjust the valve clearance if the seat is not pitted.

 

[Adevo]

Will you get off those specs as I am personally pulling the info from the dealer's Briggs' Power Portal.
Okay the specs for this 28M707-1162-E1 engine are the same as I previous quoted from Briggs Power Portal.
View attachment 67027
This is the last time I will repeat myself.

Valve Seat PNs.
View attachment 67024
And here is the instructions on valve seats from the service manual.
View attachment 67026
Personally I would leave the exhaust seat alone and just adjust the valve clearance if the seat is not pitted.

Guess I'm full of apologies today ... got the damn specs off a "spec" sheet ... clearly wrong.

Thanks for your patience. Interesting that you'd leave it alone.

So even though the exhaust valve will travel further than the intake valve because the seat on the exhaust is pushed ... that's ok? Seems like the valves should be parallel to one another (only difference being clearances) to have the proper stroke forces. Am I wrong again? Wouldn't shock me.


Thanks again for your input.

 

[Fish]

Thanks for you attempt to help me ... I love this guy ... his videos have helped me a lot.

Why they don't cut the valve seats is beyond me.

The intake valve needs to be fully staked in the whole circumference, but the valve seats definitely need to be cut. The exhaust seat looks normal, don't mess with it, just needs cut.
Here is the valve seat cutter I use.

 

[Adevo]

Why they don't cut the valve seats is beyond me.

The intake valve needs to be fully staked in the whole circumference, but the valve seats definitely need to be cut. The exhaust seat looks normal, don't mess with it, just needs cut.
Here is the valve seat cutter I use.

Thanks so much for your help.

The exhaust seat looks normal, but it's definitely beyond the lip you mentioned - which explains why there's no clearance. It also has a tad of play when flush in the seat .. it can be pushed in further ever so slightly. In looking at the valve stem I see that's it's not completely square.

I love the seat cutter you use, but it's pricey.

If you think it's a good idea to trim the exhaust valve stem to get the needed clearance, I think that's what I'll do ... put the whole thing back together and see what I've got. If it doesn't start up ... I'll have to have to buy new seats and find someone to cut them for me (plus one valve that will be way too short to reuse).

Last time I'll bug you [pretty sure : ) ]

Thanks again!

 

[Fish]

I wouldn't invest much money in an engine that has had a loose seat. I would just grind the exhaust valve stem to the correct clearance and slap it back together and see how it runs.
This venture so far has given you a pretty good education in small engines.
If it had come into my shop, I would have advised against putting money into it.

 

[Fish]

"Last time I'll bug you [pretty sure : ) ]"




Bug us all you want, we enjoy trying to help folks fix stuff.