The Jack's Small Engines Forum - Join Our Online Community
Reply to post

Helpful ReplyHot!BS 33R877_002 G1 hard crank, difficult to overcome compression

Page: 12 > Showing page 1 of 2
Author
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
2020/06/20 17:06:50 (permalink)
0

BS 33R877_002 G1 hard crank, difficult to overcome compression

2014 Craftsman (Husq built) Mower running fine until 2 weeks ago.  I went to start it and it would only turn a rev or so until it hit compression, then stop.  I figured battery so put it on a charger and eventually got the mower started with great difficulty.  Runs totally fine and mows great.  It isn't flooding and has recently had  new needle valve and bowl gasket and o-rings.
 
I have read a lot about this and learned that the valves need to be adjusted properly for the compression relief to work. I checked them 1/4" down from TDC and they were just a tad loose.  I set them both to .004 as per the local shop recommendation.  I did get it to start with a battery hot off the charger, but it still struggles to overcome compression.
 
I still have some confusion as to exactly which compression relief method this engine uses.  If it is just the cam lobe profile bumping open a valve a tad that adjustment should have taken care of it... unless maybe the cam lobe is worn badly, I suppose.  Is that how the compression relief works on this one or are there any other components that might need attention?  Or maybe the starter is failing??
 
Mower runs great once it is started.
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/20 17:30:51 (permalink)
0
OK, I just found a youtube video where a guy had the exact same scenario and he replaced the camshaft.  I saw the compression relief component, a extra spring loaded lobe on the cam.  His was broken off.  I suspect that is what's happening here.  What a PITA to have to pull the motor for that.  Oh well.  Such is life.
AVB
Super Member
  • Total Posts : 1878
  • Scores: 77
  • Reward points: 0
  • Joined: 2017/06/21 16:35:48
  • Location: Elora, TN
  • Status: online
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/21 08:52:11 (permalink) ☄ Helpfulby raylo 2020/06/21 11:02:30
0
Yes the 793880 camshaft is bad about breaking the ACR. But you can check for this problem opening up the engine any more then the valve cover. Just check by looking for the slight movement of the intake valve rocker arm as you approach TDC compression stroke. No movement then yes the ACR is broken. The ACR uses a D shape rod to slightly open the intake valve. Once the engine is running this ACR swings out and becomes non effective.
 
You will need the camshaft, crankcase gasket, and an oil seal if you open the crankcase.
 
But that shop gave bad info on the valve adjustment so got the exhaust valve clearance a little tight.
 
Intake Valve .003-.005 in (.08-.13 mm)
Exhaust Valve .005-.007 in (.13-.18 mm)
post edited by AVB - 2020/06/21 08:53:37
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/21 11:11:59 (permalink)
0
Thanks for the tip.  It is the cam...  coming up to and over TDC on compression the intake valve does not crack open.  In fact the valve remains fully shut and the clearance remains at .004 where I set it.
 
With a "hot" battery fresh off the charger the mower will start.  It just needs to get past that first compression block.  My friends say that this has probably gone on for years attributed to a weak battery.  They have had to charge them frequently and even replaced at least twice.  In fact before learning about this issue I replaced the battery for them again. With most vehicles and engines 99% of the time it is the battery.  I guess I am learning new stuff with these B&S engines.  
 
BTW, I also reset the exhaust IAW your specs.
post edited by raylo - 2020/06/21 11:16:40
Roy
Moderator
  • Total Posts : 1203
  • Scores: 23
  • Reward points: 1
  • Joined: 2016/07/27 22:51:23
  • Location: British Columbia
  • Status: online
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/21 11:20:52 (permalink)
0
That was a common failure with the Intek singles, the replacement cam is an improved design.
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/22 18:31:56 (permalink)
0
Took it apart today and indeed the cam compression release had failed.  I found a few pieces so far... the big curved articulating piece, the small end piece that broke off of it, and the spring.  I will look at the new cam tomorrow when it comes to see if there might be more stuff to fish out of the crankcase.  Otherwise the engine looked very good internally.  Super clean.
 
Here is a pic:
 
 
 
 
 
 
post edited by raylo - 2020/06/22 18:34:12

Attached Image(s)

AVB
Super Member
  • Total Posts : 1878
  • Scores: 77
  • Reward points: 0
  • Joined: 2017/06/21 16:35:48
  • Location: Elora, TN
  • Status: online
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 09:43:15 (permalink)
0
Roy
That was a common failure with the Intek singles, the replacement cam is an improved design.

Question Roy. Have you already seen the new 84005207 camshaft that replaces the 793880? This is the new part supposedly according my 06/15/2020 price file update. This new number hasn't made to my other vendors yet. Otherwise I haven't seen any noticeable changes to camshaft in the last 5 yrs.
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 10:23:01 (permalink)
0
Darn, the replacement cam I have coming is the 793880.  No wonder it is on sale.  I did a search for the new part # and don't see it offered anywhere.  Are we sure that part # is correct?  It has 2 more digits than the old one.  This seems like one of those things that should be a recall... not safety of course, but out of appreciation for customers.  They may save some money on parts but bad will is very hard to recover.
post edited by raylo - 2020/06/23 11:29:17
AVB
Super Member
  • Total Posts : 1878
  • Scores: 77
  • Reward points: 0
  • Joined: 2017/06/21 16:35:48
  • Location: Elora, TN
  • Status: online
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 10:52:07 (permalink)
0
Yes I am sure. It is from my Power Distributor's price file that I load on my system monthly.
 
The part you got coming is what they will ship until the current stock is deleted. I just got in three of the 793880 from them last week.
Matter of fact the PN I posted actually replaces all of the following camshafts. Note "B1" is the Prefix I use here so it must be dropped for actual Briggs PN.

raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 11:22:37 (permalink)
0
LOL... this is why I will never personally buy a piece of equipment (junk) with a B&S engine.  When you have to R&R an engine repeatedly for a defective part that pretty much makes it a consumable... and then they hold back the upgraded version something just ain't right.  Can't make this stuff up.
 
IMO, this thing should really be a recall... or at the very least B&S should offer the new camshaft immediately and at a discount.  They may save some $$ selling off the inventory of old defective parts, but that won't buy them any good will from customers which is worth a whole lot more.
post edited by raylo - 2020/06/23 11:41:00
AVB
Super Member
  • Total Posts : 1878
  • Scores: 77
  • Reward points: 0
  • Joined: 2017/06/21 16:35:48
  • Location: Elora, TN
  • Status: online
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 11:51:23 (permalink)
0
You ought to look some of the other brands with all their superseded parts. I got well over 200,000 part number that have gone NLA.
 
I think this Briggs part is just being sourced from another supplier of the part. Most likely a Chinese supplier that meet Briggs specs.
 
One thing you got remember is that Briggs makes thousands of these engines every year and the only engines that I see is the ones that failed.
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 12:52:05 (permalink)
0
Oh yes, I understand about superseded parts for just about anything complex that is manufactured.  But all parts aren't equal.  What bothers me about this that it seems to break at a very high frequency (I bet B&S will never share their data) AND requires engine R&R to repair.  This mower and another one were primarily used by a couple of women who aren't very mechanical and they threw some good $$ for batteries that weren't really bad. They have a newer Kohler powered Husq mower that replaced another B&S powered craftsman that blew its engine, possibly caused by the Nikki carb flooding issue.  They have these things in for annual service but all they seem to get is oil, filters, belts, and a quick look over... and the ladies never told the shop about the hard starting.  It does seem like this one did have the valves checked or adjusted at one time or another... but the shop neglected to use a gasket on the valve cover and just glued it on.  That was a PITA to get off and clean up.  Luckily I am at least able to do this repair for them which will save several hundred $.  Maybe this crappy new cam will last until we are ready for another new mower.  I have seen reports where they last only a week for some folks.... and a couple/few years for the lucky ones.
 
 
 
Roy
Moderator
  • Total Posts : 1203
  • Scores: 23
  • Reward points: 1
  • Joined: 2016/07/27 22:51:23
  • Location: British Columbia
  • Status: online
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 13:10:45 (permalink)
0
The 793880 should be out of the system, it was superceded before I retired over 5 years ago. Somebody is not moving much stock maybe you need to find another dealer. I am wondering if they are flogging cheap aftermarket parts under OEM numbers, I have seen that happen. Regarding the adhesive, Briggs does not supply a gasket for the newer engines. I hate the stuff too, try prying a Kohler Courage or Honda GC apart.
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 13:10:59 (permalink)
0
Do you guys happen to have the torque spec and tightening pattern for this 3R877_0002 G1?  Searching for this info is painful.  Otherwise I am just going to have to wing it. I am guessing about 15 lb-ft.
 
post edited by raylo - 2020/06/23 13:13:44
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 13:15:53 (permalink)
0
Roy, do you know where can I get the new part?  I searched and didn't find it.  Does Jack have it??  I can send the one I have coming back to Amazon easy enough.  Or... Hard to believe anyone is still selling 5 year old inventory so maybe the new one just comes when you order by the old number?  That would make my day.  We'll see later today when it comes.  
 
Roy
The 793880 should be out of the system, it was superceded before I retired over 5 years ago. Somebody is not moving much stock maybe you need to find another dealer. I am wondering if they are flogging cheap aftermarket parts under OEM numbers, I have seen that happen. Regarding the adhesive, Briggs does not supply a gasket for the newer engines. I hate the stuff too, try prying a Kohler Courage or Honda GC apart.


 
post edited by raylo - 2020/06/23 13:24:24
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 13:40:24 (permalink)
0
Well, LOL... it came.  And I am going to send it back if you guys can point me to someone selling the upgraded part.  Look at this label... this particular cam was made 7 years before the mower it would be going on!  I was hoping to wrap this up today, but oh, well.
 
post edited by raylo - 2020/06/23 13:42:14

Attached Image(s)

AVB
Super Member
  • Total Posts : 1878
  • Scores: 77
  • Reward points: 0
  • Joined: 2017/06/21 16:35:48
  • Location: Elora, TN
  • Status: online
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 13:55:18 (permalink) ☄ Helpfulby raylo 2020/06/23 14:01:36
0
raylo
Do you guys happen to have the torque spec and tightening pattern for this 3R877_0002 G1?  Searching for this info is painful.  Otherwise I am just going to have to wing it. I am guessing about 15 lb-ft.



220 in-lbs (18.3 ft-lbs). Just note that right at the edge of stripping the threads. I one screw to start trying to strip at 215 in-lbs.
 The torque sequence in the service manual.
https://drive.google.com/file/d/0B-g4TpKUJnh7WXBmMnJ2akI4S0E/view?usp=sharing
 
AVB
Super Member
  • Total Posts : 1878
  • Scores: 77
  • Reward points: 0
  • Joined: 2017/06/21 16:35:48
  • Location: Elora, TN
  • Status: online
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 13:58:53 (permalink)
0
Roy
The 793880 should be out of the system, it was superseded before I retired over 5 years ago. Somebody is not moving much stock maybe you need to find another dealer. I am wondering if they are flogging cheap aftermarket parts under OEM numbers, I have seen that happen. Regarding the adhesive, Briggs does not supply a gasket for the newer engines. I hate the stuff too, try prying a Kohler Courage or Honda GC apart.

Believe it or not the Briggs US distribution warehouses is still sending out the 793880 camshafts. My distributor here dropships orders directly from Briggs.
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 14:01:02 (permalink)
0
Too bad Roy got me going on this, else I'd be finishing up fat dumb and happy.  Maybe I'll call Briggs.  Should be good for a laugh.
 
AVB
Roy
The 793880 should be out of the system, it was superseded before I retired over 5 years ago. Somebody is not moving much stock maybe you need to find another dealer. I am wondering if they are flogging cheap aftermarket parts under OEM numbers, I have seen that happen. Regarding the adhesive, Briggs does not supply a gasket for the newer engines. I hate the stuff too, try prying a Kohler Courage or Honda GC apart.

Believe it or not the Briggs US distribution warehouses is still sending out the 793880 camshafts. My distributor here dropships orders directly from Briggs.




post edited by raylo - 2020/06/23 14:02:43
raylo
Junior Member
  • Total Posts : 25
  • Scores: 0
  • Reward points: 0
  • Joined: 2020/06/08 09:44:09
  • Status: offline
Re: BS 33R877_002 G1 hard crank, difficult to overcome compression 2020/06/23 14:10:25 (permalink)
0
 
 
Thanks for the manual link and tip.  I'll keep it on the light side of the spec and use blue Loctite.
 
AVB
 
220 in-lbs (18.3 ft-lbs). Just note that right at the edge of stripping the threads. I one screw to start trying to strip at 215 in-lbs.
 The torque sequence in the service manual.
https://drive.google.com/file/d/0B-g4TpKUJnh7WXBmMnJ2akI4S0E/view?usp=sharing
 


AVB
raylo
Do you guys happen to have the torque spec and tightening pattern for this 3R877_0002 G1?  Searching for this info is painful.  Otherwise I am just going to have to wing it. I am guessing about 15 lb-ft.



220 in-lbs (18.3 ft-lbs). Just note that right at the edge of stripping the threads. I one screw to start trying to strip at 215 in-lbs.
 The torque sequence in the service manual.
https://drive.google.com/file/d/0B-g4TpKUJnh7WXBmMnJ2akI4S0E/view?usp=sharing
 





Page: 12 > Showing page 1 of 2
Jump to:
Copyright © 1994 - 2016 Jacks Small Engine & Generator Service, LLC