sick sounding b&s 15.5 ohv

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  #41  
Old 04-03-10, 06:26 AM
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sick sounding and running B&S 15.5 ohv

work still in progress
 
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  #42  
Old 05-05-10, 05:07 PM
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Angry wont't start 15.5 ohv b&s

Hi all
well i got my self well enough to put the motor back together and here what i got it will not start.....the first thing i chk to make sure it was getting fire and it is then i chk if it was getting gas and it is i put some gas in the carb from the air filter. when i did that it spit back in to the carb. i ckk the valve adj it is set to the specks. i took the motor back off the tractor took the bottom sump off and chk the timming it was spot on. can any help me with this not starting motor
 
  #43  
Old 05-05-10, 11:59 PM
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Did you adjust the valves to fit to the new camshaft? If not, you will have to. Also, did you have the flywheel off? If so, check the flywheel key. I suspect if the valves are adjusted properly, the flywheel key is sheared.
 
  #44  
Old 05-06-10, 06:24 AM
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Question wont't start 15.5 ohv b&s

yes i chk the key in flywheel and the one in the timming gear both are good and adjusted the vales to new cam
 
  #45  
Old 05-06-10, 02:40 PM
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Post sick B&S 15.5 ohv

i have on the valve are .003-.005 intake
.005 -.007 ex is this correct.
 
  #46  
Old 05-06-10, 09:30 PM
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That is correct. Try another spark plug, even though you see it sparking.
 
  #47  
Old 05-07-10, 08:51 AM
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Angry won't start B&S 15.5 ohv

well here is an update i put new plug still not starting
and it is puffing oil out of the carb i disco the pcv hose from the carb thinking that was sucking oil from it. dried the carb cleaned it with carb cleaner tried to start again and it puffed oil out of the carb again.

now remember i tore the whole motor down to bare block what i'm thinking is the rings are letting oil past them i don't know about to get the bfh out any advice would help.
 
  #48  
Old 05-07-10, 02:26 PM
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Question wont't start 15.5 ohv b&s

what should be the compression be on 31c707-0230E1-030414az OHV 15.5
 
  #49  
Old 05-07-10, 10:36 PM
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Did you remove the head? If so, did you re-use the head gasket? The compression can't be accurately measured since it has a compression release on the camshaft. It sounds to me like compression is getting into the crankcase.
 
  #50  
Old 05-08-10, 05:09 AM
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Question wont't start 15.5 ohv b&s

Yes down to the block i got a gasket kit for the motor. I put all new gasket and seals in the motor.

When i put the piston in i offset the rings. Does it take some time for the ring to seat them selfs.
 
  #51  
Old 05-08-10, 08:17 PM
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The rings do seat in time, but if they are so bad off that it is causing this problem, then there is a problem. Did you check the ring end gaps before installing them on the piston? Is there any chance something got between a valve and it's seat? Try pushing each valve down and let it pop back out. If they are seating, you will hear a nice ting when they seat. If they are not seating well, they will not make much sound or may make less of a ring and more of a clunk when you release them.
 
  #52  
Old 05-09-10, 05:42 AM
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Question wont't start 15.5 ohv b&s

When i pulled the motor down i was running (badly but it was running) when i took the pistion out. I chk for ring ware there wasn't any. I could still see cross hatch in the cylnder walls the piston came out with out force.No ringe grove @ top of cylnder. I used the same rings. No did'nt take to mach shop to chk for flatness.The motor was babied i change the oil after every 3 cuts. I mowed 1.5 acr. I have ocd that way i feel if you don't take care of the motor it will let you down when you need it. before i got this damn cancer (blood cancer AML)i kept up with all my equipment.i now mow .2 of an acr and i change the oil every 8 cuts. The valve seen to be seated i open the valve use a felt marker and mark the set with thin line then i pop the valve closed nice even circle around the valve in the seated area no breaks in the in the circle. the rings seam to have have seated too. still won't start. i was plaing with the valve adjustments yesturady and i got it to back fire in to the muffler a few times now i got reset the valves again. i know i got them out if wack.
 

Last edited by bob1908; 05-09-10 at 05:45 AM. Reason: spelling
  #53  
Old 05-09-10, 09:36 AM
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Are you sure the engine is set at TDC (actually just a hair past TDC) when setting the valves? I am at a loss. If it is firing, has compression, has correct amount of fuel and air, and the valve and ignition timing is right, then it should run. You may have to go back and re-check the basics.

Here's a thought...does the valve cover have a dent in it? If so, and it's in the right spot, it can hold the rocker arm down and keep a valve open a little bit. Then when you pull it off to check valve operation, everything is working fine, then messes up again when you put it back on. Known to cause a head-scratching moment.
 
  #54  
Old 05-10-10, 05:03 AM
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Question won't start 15.5 ohv

Hi cheese:
i Have tried to start the motor with the valve cover on and off no Differance. except that oil leak on to the muffler(ha ha ) you don't think useing the old ring will cause a problem. i will kake some pix and put a link on the web site.
 
  #55  
Old 05-10-10, 08:15 AM
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Question won't start B&S 15.5 ohv

if the dots on the cam and other on crank gear are alined
is that not top dead center.
 

Last edited by bob1908; 05-10-10 at 08:16 AM. Reason: spelling
  #56  
Old 05-11-10, 11:36 AM
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Post wont't start 15.5 ohv b&s

ok i tore the motor back down to bare block!!!
question 1 when i put the pistion in how do i need to put the gaps in the rings for example first ring or the oil ring @ 12 2 ring or middle ring @ 6 compression ring or top ring @ 12???

2 question when i aline th two dots one on the cam and one on th crank gear is that tdc????

i hope i can get this motor running again any body with some idea you are welcome to leave a post
[img]100_0997[img]
 

Last edited by bob1908; 05-11-10 at 12:06 PM. Reason: adding info
  #57  
Old 05-11-10, 03:58 PM
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Angry won't start B&S 15.5 ohv

going out to try to start this darn motor
 
  #58  
Old 05-11-10, 09:46 PM
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No, as I recall, the engine is not at TDC when the dots are lined up. The sump cover must be installed, then rotate the engine with a pencil or straw in the spark plug hole until the piston comes all the way to the top on the compression stroke, not exhaust stroke. When it hits the very top, this is TDC. Continue to rotate it clockwise (when viewed from above the flywheel) until the piston has gone back down 1/4". This is where you set the valves.
 
  #59  
Old 05-12-10, 07:44 AM
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Question wont't start 15.5 ohv b&s

well it is btdc when the dots are alined it still won't start it is getting gas ,fire and has compression i not undestanding why it won't start i dump some gas in to the carb and it spit in to the muffler but didn't start. any ideas leave a post im @ a lost
 
  #60  
Old 05-12-10, 09:52 PM
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So I assume you set the engine to the proper spot and checked the valve clearances? What exactly did you do, and what pieces did you remove. This should be simple and I think you're missing one of the basics.
 
  #61  
Old 05-13-10, 05:27 AM
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Question wont't start 15.5 ohv b&s

I took the pistion out the crank out the head off the counter weight off(anti vib weight) oil slinger out tappits push rods for the valves out. I took it down to the block. regreased it and put back together. Reset the valves intake .003 to .005 i used .004 ex .005 to .007 i used .006. The motor turns over lkie it should has compression enough to blow a plug out i had it started but not screwed all the way in. I also change the coil/mag and installed another new spark plug.

yesturday i was messing with it and dumped some gas down the carb turned the motor over and move the throtle from choke to low speed real fast back and forth and the motor spit and pop into the muffler and if i kept running the starter it would every once inawile pop in the carb.
 

Last edited by bob1908; 05-13-10 at 05:46 AM. Reason: adding more info
  #62  
Old 05-13-10, 05:56 PM
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Question wont't start 15.5 ohv b&s

YouTube - 100_1029.mov


a link showing inside of motor video
 
  #63  
Old 05-13-10, 07:22 PM
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The popping in the carb can only be a few things.

-Improper spark plug firing due to sheared flywheel key, bad plug and/or coil, pinched or otherwise shorting kill wire. Could you have put the coil on upside down? Could the coil kill wire be pinched behind the starter? I've seen that a few times and it causes the problem you've described.

-Incorrect valve timing as set by the timing marks on the crankshaft and camshaft, or misadjustment, sticking valve, burned valve, or bad valve seat. (doubtful of valve seat problems if it has good compression).

The answer to the problem is listed here, I just can't tell you which one it is without being there to check it myself.
 
  #64  
Old 05-14-10, 05:36 AM
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Question wont't start 15.5 ohv b&s

hi all
i removed the coil and put a new one on. made sure i mounted it cylnder side down. i disco the kill wire chk the coil was puttout fire two differante ways 1 with my hand (darn that hurt) and the outher with a sparkplug that was grounded. the valves are moving, i didn't messure the Travail of the rocker arms. i chk the key in fly wheel yesturday it was good.
 
  #65  
Old 05-19-10, 05:19 AM
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Smile running 15,5 ohv

thanks again cheese and everyone who left a post after spending 20.00 on keys igot an heavy duty key and every thing is great thanks again and yes i was wrong it was a key
 
  #66  
Old 05-19-10, 10:40 PM
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Good, glad you got it. One more thing... the key needs to be a standard briggs key, not a heavy duty steel key. The reason for this is if the engine comes to s sudden stop, you need the key to shear. If you have a heavy duty steel key in there, it can ruin the crankshaft or even worse, crack the flywheel and cause it to explode (heavy cast iron flywheel rotating 3600 rounds per minute...think grenade). If the key sheared, it is because either you greased/oiled the crankshaft where it mounts (it should be clean, free of grease, and dry), or you didn't tighten the flywheel nut/bolt properly.
 
  #67  
Old 05-27-10, 06:10 AM
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i replace the key withab&S YESTURDAY i havent ran the motor till then thanks cheese
 
  #68  
Old 05-27-10, 09:29 AM
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Good job! Glad we were able to help!
 
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