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View Full Version : 24hp Briggs ESL seems like HIGH compression


jase4tiff
09-25-2008, 10:17 AM
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

Restrorob
09-25-2008, 11:54 AM
Model and type numbers will be helpful; http://www.lawnsite.com/showthread.php?t=144040

Do not open this engine up yet.....

topsites
09-25-2008, 12:04 PM
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.

jase4tiff
09-25-2008, 01:39 PM
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.

Restrorob
09-25-2008, 05:57 PM
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

pugs
09-26-2008, 10:56 AM
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.

Why would the flywheel not be in place? You dont need the engine to be mounted to anything for the starter to spin it.

jase4tiff
09-26-2008, 04:57 PM
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!

jkilov
09-26-2008, 05:11 PM
Is the compression release working ?

jase4tiff
09-26-2008, 05:13 PM
I am not really sure if its working i have watched both valves and cant really see a "bump" where it releases the compression unless its so small of a bump i am missing it..>??

Restrorob
09-26-2008, 05:37 PM
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.

jkilov
09-26-2008, 05:39 PM
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.

Restrorob
09-26-2008, 10:46 PM
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.......

jase4tiff
09-26-2008, 11:29 PM
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!

topsites
09-27-2008, 12:24 AM
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

jase4tiff
09-27-2008, 12:30 AM
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.

Restrorob
09-27-2008, 10:03 AM
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......

jase4tiff
09-27-2008, 03:26 PM
Mod= 446777
Type=0302 E1
Code=040306YG

Restrorob
09-27-2008, 04:13 PM
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....


http://i107.photobucket.com/albums/m314/Restrorob/Briggs/Intek%20Twin/BriggsIntekTwinValveAdjust.jpg

jase4tiff
09-27-2008, 04:38 PM
Ok Rob that got it fired right up! I just hope that i have them set correct.... If not what will happen? I didnt run it long but just hearing it run for a sec im excited i still have to do the finishing touches on wiring. Thanks so much for all your help!

Restrorob
09-27-2008, 05:21 PM
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.....http://www.xtremesystems.org/forums/images/smilies/thumbsup.gif

jase4tiff
09-27-2008, 05:27 PM
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

Restrorob
09-27-2008, 05:53 PM
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 ?