Need mechanics help for repair - Honda GCV160

Discussion in 'Mechanic and Repair' started by Roger, Apr 22, 2010.

  1. Roger

    Roger LawnSite Fanatic
    Messages: 5,940

    OK, let's start at the top. First, I admit a dumb mistake, so let's get that clear at the beginning. So, hanging my head in shame, tail between legs, let me get on with the problem.

    The punch line: I need help with a broken timing gear.

    A friend of mine spoke to me last Fall. He bought a pressure washer, albeit a small one, not of good quality, but thought to be adequate for his homeowner tasks. It is powered by a Honda GCV160 engine, pressure rating of about 2,500 psi, with flow of about 2.5 gpm. These specs may not be quite right, but you get the idea of the size of unit. He said the pump was broken. He asked if I thought a new pump could be found and mounted. I did some online research, and found one that was intended for a one-for-one replacement for the specific model. However, he did not make a decision about the problem.

    In early March, he asked me again what I thought. In the end, we decided for me to get the pump, and I would get it installed. He is an outstanding cabinet maker (retired for many years now), but mechanically, he doesn't do so well. The job looked pretty simple and straight forward. I ordered the pump, and, after some delay, arrived.

    Last weekend, I got his washer unit, and put it up on a table in my driveway (plywood sheet on horses). I unbolted the old pump. That meant the engine was completely loose from the unit. Three bolts fastened the pump, through the frame, and screwed into the engine base. There were no other connections (e.g. low pressure sensor). The pump is a direct drive, through a keyed shaft out of the engine. Perhaps this is how they are all done -- only one I've spent time tearing apart to some extent.

    With the engine loose, and my single-handed attempt to get the new pump positioned in the right place, get bolts through the frame, and started in the engine base, I quickly found I was short a hand or two. Many failed attempts happened, and the engine was not tied down. The inevitable happened -- the engine fell off my table (told you "dumb mistake").

    After more work, I finally got the three bolts through the pump, through the frame, and screwed into the threaded holes in the engine base. In reality, the replacement should have taken all of 20 minutes, but I wrestled with it more than one hour.

    When the engine fell off, I did a quick examination. I feared the gas tank was the most vulnerable. In checking for damage to the tank, I found none. Also, the exposed stub shaft was vulnerable, but no damage to it either. I did notice that the OVC cover on the front had a ding in it -- just cosmetic damage to the cover.

    I got it all hooked up the water, wand hose, etc, and tried to fire it up. No success in getting it started. The owners assured he he had run it late last Fall with no problem. After some doing, I found nothing wrong. The spark plug looked good, but when looking for an arc across the electrode of the plug when grounded, and pulling the cord on the engine -- no arcing across the electrode. This means no spark. Why?

    My only conclusion was a bad ignition module. Why would the drop of the engine cause a bad ignition module? I did some research, and found one online. Also, I found a local dealer with one (didn't realize there could be so many choices in modules for a very common Honda engine). Apparently, the module is somewhat unique because of the shutoff switch connected to the module. I'm not sure how the GCV160 is used on the consumer lawn mowers.

    I did an online search through parts manuals, but did not find the family number of the specific engine in question. Why? I wish I knew. I took the module number directly off the one mounted on the machine, not a parts manual.

    I found a dealer with an ignition module late this afternoon. I wanted to replace the dinged up OHC cover, so I took it off. When I opened up the cover, I quickly discovered I had more than just cosmetic damage.

    The timing gear had a piece broken off, the timing belt was off the cogged gear. When the cover got hit (on the drop off the table), the cover indentation hit the gear, causing the damage, and shoving off the belt.

    Ouch! This started out as a pretty insignificant project, and now I have a damaged engine, and am unsure how to fix.

    Obviously, I owe the owner his washer back in his garage, in working order. But, I now have a damaged engine that I'm unsure I can fix (many mechanics in the audience probably would consider this small stuff). Do I buy a replacement engine? Do I buy him a new pressure washer?

    I see two issues. How to replace the gear? And, how to get the gear timed on the timing belt properly?

    Here are some images. I may need another post to get them all included. I'm looking for some guidance on a couple of levels.

    1. Why can't I find the parts manual online? I see a family number: 3HNXS-1871AK.
    2. Is getting the old gear out difficult? I see a protrusion on the bottom, but am not sure how it is important for the gear. It is at the pivot point of the bottom gear.
    3. Is there a repair manual online to give me guidance on how to get the timing belt mounted properly with regard to synch of the crank? The gear has lobes on it for activating the valves.

    Anybody with some thoughts about helping me out of my stupidity? Thanks.





  2. Roger

    Roger LawnSite Fanatic
    Messages: 5,940

    Here are a couple of more pics. Included are the engine labels.




  3. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029


    Take a look on the engine block, There should be a flat area on the back opposite the head with the true engine numbers stamped in place something like this; GCV160A A2R,VIN# GJAEA-1000001 ....There should be no problem looking up parts with these.

    You can look up/purchase parts here;

    I have a old GCV160 at the shop, If I remember the bottom end took a dump but the top end is good. If you can find/post the numbers off your engine I'll double check part numbers on the cam gear I have, If they match you can have the gear/cover and anything else you need.

    I'll have to look into timing this thing, I've only done one and it was a few years back so I don't recall how I did it (ole age)..... :rolleyes:
  4. morgaj1

    morgaj1 LawnSite Senior Member
    Messages: 318

    See that's what I like about this forum, guys liek Restrorob.
  5. Roger

    Roger LawnSite Fanatic
    Messages: 5,940

    Thanks for the response, Restrorob, ...

    I thought I looked it over pretty well, thinking something should be on the engine, not just the shroud. I will look again. Perhaps my eyes were crossed from the frustration of doing a stupid thing -- not the first time, won't be the last.

    Yes, the designation you offered as an example is exactly what I saw in the online places I looked.
  6. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029


    If you remove the recoil assembly and raise the flywheel cover up there will be a pad just to the left of where the decal is, That's where they hid the numbers.

    If you can't find the three letter type number as I couldn't on this one I have, Post the other number and I'll call my supplier and get them.

    I've got the coil/cam gear/valve cover and a good timing belt if needed....
  7. Roger

    Roger LawnSite Fanatic
    Messages: 5,940

    Restrorob, .. thanks for that information. However, I spent much time looking for the numbers. I finally found them, on the vertical plane. I was looking on the horizontal surfaces. Also, the aluminum had a white powder over the surface, and it took some rubbing to get them to come clean.

    I have posted a couple of pics below so that others can easily learn where to look if the need arises.

    After I got the number, I spent time online to learn more. This engine is an N5AF, and is widely used on pressure washers and log splitters. If I understand the way arrange their information, it is a pre-1997 engine. The number of variations on the GCV160 is beyond comprehension!

    I did find a place with a new engine, and was tempted to place an order and be on the safe side. But, ... my gut tells me that somehow I can get this thing fixed, albeit weekender skills. After looking closely, and knowing this is the same kind of arrangement, and materials, I am amazed that my GCV190 on my Honda HRX217 is still running!

    I took the numbers down, and headed for a dealer. After much time at the counter, I learned they had none of the parts. I wanted the dinged up cover, and the lobed gear pulley. I also wanted the clutch plates for the BBC on my HRX217 as well, but didn't have them either.

    I was really distressed because getting this fixed was on my list for today. Next week is a very heavy mowing schedule, and the weather is iffy for Monday. So, today, ... this was it. I called two other dealers, no parts in stock.

    I came home and ordered all the parts for the GCV160 and HRX217 from (Outdoor Network, LLC). So, thanks for your offer, but I will wait for the order to come from FL. The HRX217 clutch parts are not needed -- just feel the clutch isn't coming to grip like it used to and the adjustment is at the end of the line.

    While I was changing oil in my HRX217 tonight, I tried to take off the numbers of the GCV190 engine on that machine. While the numbers on the GCV160 became pretty clear after some rubbing, the 190 numbers were nearly impossible to read. I ended up with a running a lead pencil over the markings, making the numbers/letters more clear. Also, I shot a digital pic from a slight angle, in order to get some use of shadows to make them appear better. You can see the engraved numbers/letters on the 160 -- pretty clear, once one knows where to look (ha, ha), and gets the surface clean.

    I am still at a loss on how to get the shaft out in order to replace the gear. I see the shaft penetrate the lower part of the case, with apparently an O-ring seal. The shaft is not tight in the holes, rather rotates pretty easily. I see the top from the pivot point above the gear. Maybe it just pulls out with some force, ... not sure. The top protruding out the bottom is odd shaped, about 1/4" long, but with half of the shaft milled away. I see nothing mechanical holding the shaft in place.

    Yes, I still don't know how to time it either with the new gear.

    I did spend some time looking for online service manuals, but did not find anything. Well, ... not quite right. I did find one for a $34/yr subscription fee for downloads. I'll keep looking.



  8. mowerknower

    mowerknower LawnSite Senior Member
    Messages: 766

    I will take a shot at explaining this, its kinda tough to explain, a lot easier to show. You will need to split the crankcase to time it properly. There are 2 lines on the cam gear, they both need to be just visable and parallel with the case (for this part you just need to have the valve cover off, there is also a mark on the crank shaft that lines up with a mark on the block. when everything is lines up pop on the belt and you are good to go. Like I said, its tough to explain but easy to show. If the timing belt is still on you should be able to replace the gear without splitting the case, just line up the marks as stated above then mark the belt and gear with a crayon, and put the same mark on the new gear. Remove the old gear keeping tension on the belt so it doesnt move on the crank gear, then pop the new gear in lining up the marks. (I have done this once and it saved a lot of time).
    BTW the came gear shaft just slide out once the OVC cover is pulled off,
  9. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029


    Here's a PDF owner's/service manual, The bottom of page 3.4 explains/shows how to set timing.

    The cam gear pin must be positioned with the cut-out facing up so the tang on the valve cover can hold it in place.
  10. Roger

    Roger LawnSite Fanatic
    Messages: 5,940

    mower ... and Restr... -- thanks very much for your additional input. These posts help clear up my immediate questions.

    After looking more closely at the cover, I see a small flap on the bottom edge. It must key up the the bottom of the timing gear shaft, so that it does not drop down, or turn. I will not try to extract the shaft until the new timing gear has arrived.

    Restro ... the link to the manual, albeit more languages than I can use, is the good information I was needing. Also, mower... your comments will be helpful when the time comes. I'm sure it will make more sense when fitting the new gear in place, and I see the markings.

    I'll keep you posted on progress after the parts arrive. Thanks again -- great help here!

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