OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Rover Engines Rover i4500 Lawn Mower

Hey guys,

I recently picked up a quite new Rover I4500. I haven�t encountered one of these in my travels and was after a little bit of guidance before I start getting it working. Outdoorking�s documentation on these machines is pretty limited.

The whole setup is in quite reasonable condition, it will look even better after a wash.

1) I am assuming this engine is a close of a Honda but which one? I am used to working on the Sanli�s and Victa V40�s etc which are a clone of the GXV140 however I am not familiar which engine this one clones. Perhaps the GXV160? I ask this question because the valve clearances need adjusting.
2) The carby is a Huayi which I am assuming is similar to working on a ruixing carby. All copies of the Keihin I believe.
3) Compression feels quite low however I think adjustment of the valves should correct the issue.
4) I believe the blades are the same as the 19inch Honda variety. The measurements all match up correct � Would be great if somebody could confirm. 144mm * 44mm are the current blade measurements
5) The oil is really clean � if this machine has done more than 5 or 6 average mowing sessions I would be surprised.
6) The filter on the machine for some reason was very dirty. I am not sure what is going on because the machine was relatively clean overall (I suspect the airbox may not have been installed correctly. The previous owner did say he had only had it for a limited period.

Thank you

Hi Peter, to get the engine size I suggest you start with the engine type, which is cast into the crankcase. See owner manual:
http://www.ronebergcairns.com/2010onwards/general2010_5844.pdf
Valve clearances for the GXV160 are 0.006" inlet, 0.008" exhaust, which is the same as the GXV120 and GXV140, so from that point of view it doesn't matter which capacity the engine is.
The Huayi, Ruixing, and another brand I can't recall at the moment, carburetors are all close copies of the Keihin, and generally speaking the parts are interchangeable.

In my experience it takes a while for a Honda with new rings, to dirty its oil. However as you say, half-a-dozen mows of an average suburban lawn would have it discoloured, though not non-transparent. To have a dirty air cleaner in the same amount of time does sound strange - maybe it had been run more than you think, and the oil had been changed. Incidentally the owner manual I've directed you to has some detail on caring for the air cleaner. Please post a picture of the inside to show how dirty it was and where the dirt was located. Did it have the foam prefilter fitted, and was it oiled?

Well after a little investigation it appears the mower might have done a little more work than I first anticipated. Everything still seems in very good condition.
The code from the engine block is as follows: I4500212009900427.
I think at some point the filter was oiled but the pre filter was very dry when taken apart.
I have included some extra photos for the thread. I'll await your advice on which Honda engine it clones.

I am also sure this uses Honda 19 inch blades as all the measurements match up. Happy to be correct if others have more experience.

peter

Hi Peter, the blades are definitely the same as the honda blades. FYI, the blades are 124*44. When you measure a blade it's measured from the centre of the bolt hole to the tip, not end to end.
As for what it clones, GXV140 or GXV160, who knows?? they are all fairly similar from a servicing perspective. Grumpy's given you the inlet and exhaust clearances so set them, clean the carby and see what happens.
As with all choke carby's make sure the choke engages fully on start up. My experience with these is the governor plate is inferior in its design, quality and function so a little bit of adjusting and gentle manipulation may be needed to get the choke to engage at full throttle and the kill switch to activate on shutdown. It's a balancing act and you'll see what i mean, if and when it come to that.
The good part is that Rover stock, or at least can get parts for these machines unlike most of the other Chondas. i bought a sump gasket for one 2 weeks ago.
By the way, the filter looks usable, so dont ush out and replace it, they're a bit pricey for what they are. The element doesn't look oiled, just oily along the bottom on the rubber probably due to the machine being overfilled or tipped up and the oil coming through the breather and down into the assembly at some point.
Good luck and keep us posted.

I've been trying to think of externally-visible differences between the GXV140 and GXV160, and haven't come up with much. However, if you can see the carburetor insulator, that could help. The GXV140 has a thin insulator, almost the same as the GXV120. The GXV160 has a large square intake port, and consequently uses a thick insulator to make the shape transition from the small round carburetor to the large square port. It looks like this:


When it comes to getting the machine to work well, the base engine is generally just about as good as the genuine Honda, except for the PCV valve disk which is likely to be garbage but is easily replaced with a Honda one (though you do have to remove the flywheel to do it). The bolt-on bits of the engine are a mixed bag: the carburetors are generally good copies and will probably be satisfactory. The air cleaner and governor plate were not really copied from the Honda ones, and might be anything from just OK to absolutely awful. In the case of the governor plate though, I think you'll find you can bolt on a genuine Honda one from a junk engine. It will only take 5 minutes and is probably the biggest improvement you can possibly make in that amount of time.

In summary, on what I've seen so far, you can make a chonda just about as good as a Honda with very little work, simply by fitting Honda bits in the few places where the chonda bits are of poor design or quality. The base engine seems to last about as well as a genuine Honda. I think I'll be using them myself if I live long enough to wear out my genuine Hondas.

Thanks for the pointers Grumpy and Theo,

The mower has now had a standard once over and its running really well. It needs a good workout to get rid of the excess oil from the exhaust and surrounding areas as I suspect its been tipped over for an extended period. I suspect after 10 minutes or so the oil smoke will clear up like most mowers that haven�t been running for a while. The carb was gummed up. The emulsifier took a fair while to clean as the little holes were blocked with crud.

After some adjustments in the linkages it is a one pull start from cold. I have noticed this engine has a much better low idle compared to the other chonda�s I have worked on like the Sanli�s and Victa V40�s. I am little confused why the valve clearances are next to nothing when I pick up the mowers. After I adjust the valves as you indicated they all run really nicely. My research on the issue seems to confirm OHV engines need to be adjusted once every 12 months � is this wrong? It seems a little often for general residential use mowers that are only worth a couple of hundred bucks brand new.

Grumpy,

I have some photos for you to look at. I didn�t take the gaskets and spacer off as I didn�t want to break the gaskets (made that mistake last time). I have also included some photos of the linkages that might help others in the future

Lastly, what is the go with oiling the pre filter (should I be oiling it or not?) The Sanli�s seem to die quickly when you oil the filter.

I�m open to suggestions as always. I am going to take it for a good run on the weekend and make double sure its ok before it goes to a new home.

Peter, the valve clearances need to be as Honda prescribed. If they are less, the valves will leak some or all of the time, and leaking valves erode and leak more. The reason for annual adjustment is the number of wearing surfaces in a pushrod valve train, and the relative flimsiness of the parts concerned, compared with a simple side-valve valve train. Excessive valve clearance is a bad idea, though not as bad as insufficient clearance. Aside from noise and an increased wear rate due to the recurrent impacts as the valves open, the decompressor can't work if the exhaust valve clearance is substantially more than it should be. The main disadvantage of pushrod engines compared with side valve ones, is their need for more regular, and more expert, maintenance. They reward us for that extra maintenance of course, by running much better and using much less fuel.

If they are not leaking air through the insulator gaskets, and the carburetors are clean, pushrod Hondas should be able to idle fairly nicely down to about 1,500 rpm. To make them idle slower than that you would need to have variable ignition timing, which Honda puts on the postie bikes but not on the mower engines. One of the reasons for that omission is cost, but it is also important that Honda does not want the mower engines to be run slowly, because of heat soak-back. When an engine has been running hard under load for a longish time, it gets up to maximum safe operating temperature, and when you take the load off it, it does not cool down instantly. If you reduce the fan speed immediately after taking the load off the engine, the temperatures will actually rise quite substantially, due to the thermal inertia of the parts involved. Consequently it is important that a mower's operator cannot suddenly reduce its speed to an extent that almost eliminates the flow of cooling air from the fan. Of course this problem is almost non-existent with water-cooled engines, but mower engines are air cooled for reasons of weight and cost. So, Honda tells you to set the idle speed of GXV120 and GXV140 engines at about 2,000 rpm, although they will idle well at much lower speeds.

Your engine does not have the thick carburetor insulator of the GXV160. I cannot see the intake port, so I can't tell whether it is square (GXV160), D-shaped (GXV140) or round (GXV120). However we can't be sure a chonda manufacturer won't have deviated from Honda's base engine design, though I haven't heard of that happening up to now.

Chondas seem to always have their own idiosyncratic air cleaner designs, probably for reasons of visual differentiation of their engines. The usual rule for paper-element air cleaners is that you do not oil the paper element, but you do oil the foam pre-filter. However there are such things as oiled paper elements, and dry pre-filters, for reasons best known to their designers. Essentially, you can't reliably and repeatedly clean an oiled paper filter, though I've done it successfully to a dry paper element that became completely oil-fouled on a worn, smoky engine. It sometimes works on good-quality filters, but it also weakens the structure of the paper element - hence I do it but don't recommend it. So far as foam pre-filters are concerned, the effect of oiling depends on the density of the foam. The rather low density urethane foam used in Briggs foam filters, and most Honda pre-filters, will not remove very much dirt from the incoming air unless it is oiled. If you just want it to filter twigs and chook feathers, don't oil it. You will, of course, then have to replace the paper filter fairly often because it will become fouled with various wet and dry contaminants, and only dry dust can be removed from it. If you oil the foam prefilter, it will stop nearly all of the dust, and even more of the oily exhaust, and you will wash it whenever it appears dirty, then put it back into service. The paper filter will last more or less forever if you do that. Being a cheapskate, I prefer that system myself. On the other hand if you are cursed with a higher-density foam pre-filter and you oil it, you may find that your engine cannot get access to much air, and it will run as if the choke were closed all the time. The solution is to procure a proper dry paper filter with a detachable low-density foam pre-filter, oil the prefilter, and clean the pre-filter as often as necessary. Of course you also inspect the paper filter each time, and blow it out from the inside with low pressure air if it gets grubby.

Grumpy, the explanation on the adjustment of valve clearances is exactly what I was after so thanks for taking the time to explain it in detail.

I always replace the gaskets if they are damaged however for some reason this engine just appeared to have a much smoother low idle compared to other clone engines. It may be something to do with the carby being a Huayi and not the usual Ruixing but I can�t be sure. The configuration of both carbys appear to be a close copy of the Klein Honda uses. The only bad point of these copy carbies I can find it getting the emulsifier out. I usually soak it for a while as they are really easy to damage if you try and force it out. I have wrecked one and learnt my lesson before so hopefully it won�t happen again.

The insulator gasket was definitely a � D Shape� internally so I am assuming this will be the clone of the GXV 140 rather than the 160 which follows on similar to the Sanli�s, Gardeners Choice, Victa V40�s etc model range.

I have oiled the pre filter only as you instructed. The original filter I have left in place as per Bigted�s recommendation. I did however give it a thorough clean.

Lastly as with all mowers I haven�t work on before I like to take them for a run in the long grass to see how they perform. For some reason I had higher expectations of this mower compared to the Sanli and Gardeners Choice but it was no better. The engine really struggled under moderate (knee high grass) load however it did get the job done. The fact the grass was a little wet didn�t help. The mower starts on first pull both hot and cold has no smoke whatsoever now so that�s a plus. It did take a little while for the excess oil to burn out of the exhaust chamber buts its right now. Performance wise it will suit your average household well but it is definitely no workhorse.

The plastic carburetor insulator on the GXV160 and the chonda clones of it, is quite distinctive. Here is a picture of the chonda 163 cc engine (same as GXV160 - this particular one is branded Rato) on my Ryobi pressure washer:


I've put a red oval around the carburetor insulator. It is 15 mm thick, and has a larger flange on the carburetor mounting side. The GXV120 and GXV140 insulators are only about 6 mm thick, so you can identify a GXV160 clone from a couple of metres away.

Incidentally this engine has a Ruixing carburetor. The engine works perfectly, as I would expect considering it has only run 2 hours.

At this point I don't know whether your mower has a GXV120 or GXV140 chonda. The way to tell the difference, if you have the carburetor off, is to look at the intake port, not the gasket. The standard gaskets Honda sells are D shaped for both engines.

The insulator is definitely not 15 mm thick. It was 5-6mm by my measurement

The intake port was a D shape � well a mirrored D shape when you look at it. I hope that makes sense.

Well from a technical perspective this mower is running spot on now and with some care it should last a few more years.


Nice pressure washer. Do you like the petrol ones? I have an electric unit and it�s a little temperamental at the best of times, it doesn�t like to turn on and I was thinking about upgrading to a petrol one. Just not sure which one to buy given the multitude of chonda�s on the market. Cant really justify purchasing a genuine Honda unit!

The D shaped intake port means it is a GXV140 clone, which means it is 5.0 advertised horsepower. That should be enough to knock down tall grass very easily, so I suspect you were suffering from clogged grass chute when you did your trial cutting test. The GXV160 is only 5.5 advertised horsepower, not much different. As I think I've said previously, the base engines of the chondas seem to work and last as well as the Hondas they are copied from, if you put aside a couple of minor short-cuts the copiers have taken.

I find the petrol pressure washer a bit of a hassle, because I use it rarely so I drain the fuel after every use. However at 5.5 hp and 2,400 psi, it is in a different league from any of the electric ones that I've seen. The petrol ones are different machines to use, compared with the small electric ones, because the engine keeps running whether you are squirting water or not. This means it has a high-volume bypass built in, to keep the water in the pump from boiling immediately whenever you release the squirt-lever. It also has a secondary safety system: if you leave it running without squirting for several minutes, it will do an emergency dump of hot water from the pump onto the ground, to keep it from cavitating and destroying the pump. It's kind of an industrial-strength machine rather than something you wash the car with. It sure can remove 40 year old crusted black mould from a concrete driveway though, if you don't mind getting plastered with back-blast. I've also found it has a near-miraculous effect on old industrial-type carpet tiles that have gone brownish with trodden-in dirt over a period of years. Once again though, you get seriously coated in crud when you do it.

Like most purchases of machinery, I only bought the washer because it was cheap. The previous tenant bought it and immediately tried to use it for hydraulic mining on a building site. He put the water intake hose in a mud puddle and started squirting a clay cliff, so the pump would pick up the run-off and pump it at the cliff again. Of course the pump intake filter blocked immediately. He tinkered with it a bit then put it on ebay saying that the pump was a total loss but someone could remove the engine and put it on a lawnmower. Opening bid was $25, and I was the only bidder. The spark plug insulator was still glaring white like a glacier - must have run 10 minutes or less I think. It took just a few minutes to clean the pump filter, clean out the nozzle that he'd been shoving into the clay cliff, and then do a new-engine tune up.

Thanks Grumpy. I cant justify buying a new petrol washer so I'll try and find one that needs some work. Hopefully I find one at the local junkshop one day.

The rover performed much better in the long grass when it was dryer. Hasnt rained in a few days here so much better for testing mowers. Its gone to a new home now and should be right for at least another couple of years.

Thanks for your help (including Bigted) in getting this one off to a new home.

Thread can probably be closed

Thanks for that update, Peter. So far as the pressure washer is concerned I suggest you avoid buying one that is cheap because it has pump problems - if it has scoring it won't be fixable, and if it needs parts they may not be affordable.

I haven't had anything to do with modern Rover frames, but the old locally-made ones were quite good. That chonda engine should last better than a Briggs, provided it gets any small repairs needed along the way. Incidentally an Outdoorking member, roebuck, has accumulated more experience with repairing chonda engines than anyone else I know, and is likely to be able to help if you run into strange variations in the design of chonda parts. He even has experience in obtaining spare parts for them.