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24hp Briggs ESL seems like HIGH compression

14K views 21 replies 5 participants last post by  Restrorob 
#1 ·
I have a 24hp Briggs ESL that seems like high compression. If i hit the starter it seems like a weak battery but pull the plugs and it turns fine. I have read some post on this same issue so i checked and rest the valves to .004 and .007 and still isnt getting it. How hard should this engine be to turn over by hand? i know thats a crazy question but i can turn it by hand but of course its a little bit tough. The engine is off the mower so i know its not safteys or anything like that. I hope that i dont have to drop the pan and check the cam to make sure everything there is ok and that mabie i just didnt adjust the valves correct i adjusted them 1/4 past tdc. If any of you guys could help id appriciate it! Thanks
 
#2 ·
#3 ·
No...

I am thinking your engine will be hard to crank so long it isn't on the mower,
due to the fact there is no flywheel in place, this is perfectly normal.

I hate to say it but you should install it before testing :p

If it's brand new, soon as you put gas and oil in it you done voided the
instant return warranty anyhow, so go on and put it on that machine I say.
 
#4 ·
I agree that it needs to be bolted down this engine is not the origional engine i was going to try and replace it with this Briggs 24esl engine i had a Kaw 23 hp with the common top bushing bad that i am repairing and was going to set this engine up on the mower for the time being the mower is a John Deere 657 quick trac. The numbers off the briggs engine is 24 ESL 725 and family number is YESX57242VF275363. Thanks for your help. I will work on mounting the engine for proper testing this is a used Briggs engine that came off a cub cadet.
 
#5 ·
OK, The numbers you posted are not the ones I was looking for, The model type and code numbers are stamped in the top of one of the valve covers.

But, I really don't need them now.

I believe your problem is the valve adjustment. Rotate each piston to TDC compression stroke and adjust the valves at that position to .005 both intake and exhaust.

That's right, These V-twins are adjusted at TDC.....


Good Luck
 
#7 ·
Yea i didnt get that one either but for now i did bolt it down and i adjusted the valves to .004 and i took one plug out and hit the starter. When it hits compression it stops i do belive that valves can be an issue but i have them close and this engine should at least give me a full revolution atleast. So it makes me think that its the cam or the compression release system. If i pull the pan can someone tell me what the compression release system looks like on this engine or what it supposed to look like? Does it have a arm that swings out or is it a lobe on the cam or what. Thanks guys for your help!
 
#10 ·
The release if working properly will show a distinct movement in the intake rocker arm. As the piston travels up the cylinder you will see the rocker arm moving up (toward you), The rocker will stop for a second then should move back down (away from you) enough to be easily seen then travel back up toward you.

The compression release is a spring loaded arm mounted on the cam gear.
 
#11 ·
Well if you got the valve cover off you should see the intake valve hop on compression stroke. Funny....

Sorry but I don't know the exact procedure for testing the release mechanism. A compression test would tell a lot.

I think the mechanism works only one way though. So if you rotate the engine backwards via flywheel it should feel much harder to turn. If it's the same either way then suspect the mechanism is faulty. Probably not the expert way of doing it but might help.
 
#12 ·
Sorry but I don't know the exact procedure for testing the release mechanism. A compression test would tell a lot.
The release if working properly will show a distinct movement in the intake rocker arm. As the piston travels up the cylinder you will see the rocker arm moving up (toward you), The rocker will stop for a second then should move back down (away from you) enough to be easily seen then travel back up toward you.
Hmmm.......
 
#13 ·
Restrorob i think that i am adjusting the valves correct or i hope. What i am doing is putting piston at TDC then im not sure is the exuast valve the top one or bottom i think its the bottom. When its at TDC the intake valve is the one that i can adjust the exaust still has tension on the rocker arm and spring....does that make sence or am i talkin somethin crazy? So what im wondering is how can i adjust both at TDC or should they both be loose at TDC where you would get the .004?? Sorry guys!
 
#14 · (Edited)
Why would the flywheel not be in place? You dont need the engine to be mounted to anything for the starter to spin it.
Parts of the mower itself such as the pulleys and sometimes the belt
ACT as a flywheel, it may not be much to it but those pieces give the
crankshaft extra weight and without that weight the engine will fail to turn
over properly as it doesn't have the benefit of that extra weight's momentum
to carry it past TDC the starter can't do it on its own.

I'm not saying it couldn't be the valves, but before tearing into the engine
one should really have it properly mounted first, more so if the engine ran
fine before or if it's brand new.

Now I realize this next part is someone else...:

Yea i didnt get that one either but for now i did bolt it down and i adjusted the valves to .004 and i took one plug out and hit the starter. When it hits compression it stops i do belive that valves can be an issue but i have them close and this engine should at least give me a full revolution atleast. So it makes me think that its the cam or the compression release system. If i pull the pan can someone tell me what the compression release system looks like on this engine or what it supposed to look like? Does it have a arm that swings out or is it a lobe on the cam or what. Thanks guys for your help!
Well all right, all I wanted to do is help eliminate one more of the possible causes.
If that's not it and you end up having to remove it again I am sorry to have wasted your time,
but it's about doing things in a proper fashion, to me it is.

Don't forget to put oil in it first :p
 
#15 ·
I misunderstood you yes now it is mounted and everything is in place but the engine still will not make it past TDC and its very slow turning the engine over before it even hits TDC. Just to rule out the battery i used my battery charger to try and start it and it does the same thing. So i dont know mabie the starter is bad??? I guess its possible.
 
#16 ·
OK, The numbers you posted are not the ones I was looking for, The model type and code numbers are stamped in the top of one of the valve covers.

But, I really don't need them now.
At this point I have changed my mind, Post the numbers......
 
#18 · (Edited)
So what im wondering is how can i adjust both at TDC or should they both be loose at TDC where you would get the .004
Bingo ! TDC compression stroke will have both valves closed with no tension on either spring. The bottom valve is the intake, I think you are trying to adjust on the exhaust stroke which is what's giving you the problems....

 
#20 ·
If you set them to spec and tightened the jam nut they should be fine.

If not what will happen?
As you have been dealing with, If they are too loose the engine wont crank due to the compression release not functioning properly.

If they are adjusted too tight the valves will not close fully thus causing back-firing or fuel spit-back through the carb.

Glad it's finally spinning over.....
 
#21 ·
Ok sounds good Rob mabie you have a way of getting wire diagrams. What i have a John deere 657 that had the kawasaki 23hp engine and now i am putting this briggs engine on and i just want to make sure that i dont burn ne thing up but cant seem to find a diagram on either that says the red is this or the black is that to help me. Thanks again
 
#22 ·
The best way to do something like this is to forget about wire colors, Trace each wire in the harness to it's respected component on the Kawi then do the same on the Briggs. Then hook the same Briggs component wire to the same place it was on the wire harness for the Kawi.

Hope that made sense ?
 
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