Replace Cylinder Head

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  #1  
Old 05-20-13, 04:33 PM
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Replace Cylinder Head

Hi Everyone:
Glad to be part of this community. I have a dillemma. Stupid me was trying to remove the spark plug from my pressure washer and I stripped the hole. Hopefully someone can reassure me that all I need is to replace the cylinder head. I don't think the pressure washer is toast, but you knowledgeable folks would know. I'm including a photo. The pressure washer is a Generac 2700psi/Model#0Q61490. Many Thanks, Don.
 
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  #2  
Old 05-20-13, 04:39 PM
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No need to replace the head unless it's really cheap. You can buy a Heli-coil kit and use an insert. A small engine shop would probably do the same thing.
 
  #3  
Old 05-20-13, 05:34 PM
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Thank you very much Gunguy45 for getting back to me so quickly and for the help. I looked at YT videos on what you suggested and looks somewhat simple. But i'm afraid of one thing, the surface of the head hole has a small chunk out of it(see photo) and I don't think that heli coil kit addressed that. I looked around the web and it seems as though the cylinder head replacement part is about $45.00. Is a cylinder head difficult to replace on my powerwasher? Many Thanks again. Don
 
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Old 05-20-13, 06:10 PM
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Cylinder head replacement

The cylinder head shouldn't be very hard to replace. You would just take the shroud off and take the bolts off holding the head on. Be sure to replace the head gasket if you decide to replace the head itself. It will leak if you use the old gasket and the engine won't run properly. By the way, what brand is the engine?
 
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Old 05-20-13, 06:13 PM
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Motor is a "Generac OHC 196cc"
 
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Old 05-20-13, 06:16 PM
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Oops....missed the missing chunk. That's where the plug seals most likely. Yeah..replacement is a good idea.
 
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Old 05-20-13, 06:42 PM
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I was under the thought that it would cost in the range of 90-100. 45 isn't so bad.
 
  #8  
Old 05-20-13, 07:01 PM
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With a new head it will be necessary to transfer a lot of parts from the old head plus valve adjustments etc. So install a helicoil, apply JB weld to the damaged area, now get it running and see that the pump isn't shot from setting over the winter, run it for a while, then decide if it is worth replacing the head. Have a good one. Geo
 
  #9  
Old 05-21-13, 04:22 AM
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@geogrubb: Thanks for the info. I was only just using the pw last week, so the pump is fine. I had no idea that putting on the head involves so much. I thought it was set it and forget it. Do you think the jb weld would hold and work on that area? What about the shavings from the heli coil getting into the head. Wow, I really screwed this all up. Many thanks guys.
 
  #10  
Old 05-21-13, 08:58 AM
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If it were a flathead engine replacing the head would be very simple however in the pic it looks like you have a OHV engine which has all of the valve train attached to the head. Crank the engine over a few times to blow the shavings out. If the heli coil works you have saved $$$$$ if it doesn't you can then replace the head. Have a good one. Geo
 
  #11  
Old 05-21-13, 12:09 PM
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You need a specific tap, that will come with the helicoil kit. Best thing is to grease the tap which will collect all the shavings.

I'd have to wonder how much a shop would charge if you pull the head, take it to them for repair, buy a new gasket and reinstall. Or if you buy the new head and pay them to swap parts?

The kit is probably going to run $25 or so? I see knockoffs for much cheaper...but can they be trusted? And how do you ensure the plug washer sealing surface is perfectly flat if you use JB Weld?

Not saying it won't work...no small engine mechanic here...just trying to understand how it would be done.
 
  #12  
Old 05-21-13, 02:14 PM
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Well, I will be buying the head. I actually took the head off and the all the internals. It seems fairly easy. There is alot of carbon buildup all around. Should I address that, and how do I remove it. I can upload pics if necessary. Thanks guys.
 
  #13  
Old 05-21-13, 02:18 PM
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You are doing the right thing VengeFulHemi, get rid of the bad and be done with it!
 
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Old 05-21-13, 10:14 PM
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Agreed. The head is too cheap not to replace.
 
  #15  
Old 06-26-13, 05:27 AM
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Hey guys, here is an update: On 5/23 I had ordered a cylinder head from "Jacks Small Engines". When ordered that day, the rep on the phone said that they would have the parts in their warehouse to ship to me the next day. From the third day after that, everyday I would check, the date they would recieve the part to ship to me would be pushed back each and every day. Finally yesterday, I called to cancell the order and am now waiting from another who says I will have the part by monday. If I weren't the retard I was, I wouldn't be going through this to begin with. I am just a bit nervous about reassembling the valve assembly.
 
  #16  
Old 06-26-13, 09:48 AM
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Don't sweat it, they are pretty easy to change.
 
  #17  
Old 06-26-13, 02:57 PM
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Relax dude,,,,Jack's will get you your part! Everyhing will be fine......
 
  #18  
Old 07-01-13, 04:45 PM
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Got the new cylinder head today. One thing I can't figure out is which is the exhaust and intake valve and then their proper positioning? I have the pdf for the PW, but it's too large for the upload. Here are a few photo's. Many thanks to all of you.

Don
 
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Last edited by VengeFulHemi; 07-01-13 at 05:27 PM. Reason: Added photo's & text.
  #19  
Old 07-01-13, 09:17 PM
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The exhaust one is the smallest one. It's black from heat and oil cooking on it.
 
  #20  
Old 07-05-13, 05:32 AM
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In terms of preventing this from happening again, how did you tear up the threads? Did you cross thread the plug putting it back in or were the threads locked up and tore out when you took the plug out?

When you put the new one in just turn it in finger tight until it seats against the head. Then finish it with a wrench.

Also use an anti seize compound on the threads. Saves a lot of grief taking them out in the future.
 
  #21  
Old 07-05-13, 09:26 AM
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Ok, I recieved the cylinder, put the internals back together, and are awaiting head gasket and cover gasket. Now here is the next issue: I need the valve clearence specs and generac does not provide them to the average consumer. I called a power equipment place by me here and they said that they don't have that info. Now i'm stuck. If anyone here can possibly get me the bolt torque specs for the cylinder head and thevalve clearence specs for the valves, I would be truly greatful. Here is the PW info:

Generac 2700 psi(it's a generac engine)

196cc

Model#: 0061490

Sn# 6287274

Many thanks to all of you for your valuable help.

Don
 
  #22  
Old 07-05-13, 09:29 AM
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@marbobj: All I was doing was slowly backing out the plug and it started off fine, then snagged all of a sudden, then tried to slowly reseat it and started to bind up on me. Then that was the demise of it all.
 
  #23  
Old 07-05-13, 11:07 AM
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Use anti seize on the threads, but I suspect the plug was overtorqued and pulled the threads out of shape.
 
  #24  
Old 07-05-13, 01:46 PM
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There are also torque specs for the head bolts as well as a pattern. When I replaced the head on my Tecumseh flathead this spring, torqued each bolt to 200" lbs in increments of 50"lbs starting at 50. There was also a pattern that I followed while torquing that I found in the engine's service manual (it was a star based pattern) So it was 4 rounds of torquing, 50, 100, 150, 200.

Engine fired right up and has been fine since. Be sure to remove any remnants of the old gasket before installing the new one.
 
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Old 07-05-13, 06:46 PM
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I don't know the specs on the valves for that engine, but on almost all OHV small engines, .005" is a safe setting for both valves.
 
  #26  
Old 07-25-13, 07:20 PM
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A shout out to all you thoughtful people who assisted me to make this repair to my PW. It seems to be working well. Started it up after bolting on the head, adjusted the valves to .05, drained&fill with fresh earl(purposely misspelled), some fuel, choke-pull and CONTACT!!! You guys are cool! There is just one thing that concerns me just a bit. While bolting on the head, I first did 130in, then I had it set for 160in but the bolts started started to get so tight that I didn't want to chance snapping a bolt head. So my torque wrench never clicked. Am I going to see problems soon with this? Again, many many thanks to all of you.

Don
 
  #27  
Old 07-25-13, 08:23 PM
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Glad it's running!

160 in lbs isn't that much really. I wonder if something is wrong with the wrench. Try it on a bolt somewhere else on a trailer hitch or something so that you can feel how much it takes to make it click.
 
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Old 07-26-13, 03:08 AM
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What can happen if the bolts are not tight enough? Thanks.
 
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Old 07-26-13, 06:22 AM
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It will blow out a head gasket.
 
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Old 07-26-13, 07:10 AM
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But there are problems with over-torquing, too. You can strip the threads or, on the smaller bolts, break them.
 
  #31  
Old 07-26-13, 05:33 PM
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Well, ran into two issues today. I tried to retorque the bolts and busted the thread and head off of one(luckily lowes had an exact match on them),whewwwww. Then I had to go away for the day, so I asked my neighbor to spray som wd40 I had in the garage to help penetrate the busted bolt. The friggin dope used my blaster spray lubricant and he said a tiny bit got into the cylinder. I am going to use a left handed drill bit tomarrow to try and remove the leftover bolt, but is there a concern about a bit of the spray lubr getting into the cylinder? Many thanks to all of you.

Don
 
  #32  
Old 07-26-13, 08:46 PM
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It won't hurt it,,,,the spray that is.
 
  #33  
Old 07-26-13, 09:45 PM
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Looking up your model number, I show the head bolt torque to be 140 inch pounds. Where do you get the 160"lb value from?
 
  #34  
Old 07-29-13, 06:35 PM
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@mowerdude: Hey buddy, thanks sooo much for that info. I feel better now.
 
  #35  
Old 07-29-13, 06:57 PM
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@cheese: A thousand pardons for the delay, tons of bull going on in this house. Dumb*ss me(all my fault) just confused myself because I was looking on briggs website to get an average on in lbs and saw 160in lbs. So I wasn't paying attention when torquing and inadvertently dialed in 160ft lbs. It was getting nice and tight and I figured no harm no foul. So what felt like the click of the torque, was actually the snap of the bolt halfway into the mounting hole. So I went to harbor freight and got me a corded drill and a set of left handed bits. So today I used a punch for the pilot, and slowly reversed the bit and whamooo! The broken bolt came out with just the bit resting on the surface of the bolt. Snugged it up to 140in lbs(11.666ft lbs on my wrench). Leveled the oil, gased it up, and it started and ran perfectly. Shut it down for a few hours while I cleand off the tools and put away. Now I went to start it up, I couldn't pull the darn cord, and now is leaking gas and it wont start. I had forgotten, I did adjust the valves to .05. So now I have solve all problems only to have another surface. I can say that the leak does not seem to be coming from directly under the bowl, but I can't seem to see where it is. I'm almost at the finish line here. You dudes are the best. Thanks sooo much for all of your help.

Don
 
  #36  
Old 07-29-13, 08:33 PM
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Sounds like a bit of trash got stuck in between the inlet needle and seat in the carb. Might have to pull the needle out, flush the carb and seat and clean the needle.
 
  #37  
Old 07-29-13, 08:49 PM
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You are very welcome VengeFulHemi,,,,,,,,,you'll get this thing licked.
 
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