OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions on Other Engines A different Chonda - Automatic 118cc

Hi Guys,
On Saturday afternoon I picked up something very different from the recycle centre. The mower came with a catcher and appeared to only have a fault with the throttle cable which was easily rectified once I bought it home and made a couple of adjustments. The mower starts really easily however doesn�t idle really well however I suspect with a thorough carby clean and valve adjustment the mower will run reasonably well. At full speed the engine runs spot on.
As I haven�t worked on one of these before I was curious which Honda it copies. I am thinking it might be the Honda GCV135 or similar however I am not 100% sure. I just wanted to get the correct valve clearances and read over the right manual to start with.
For everyone�s reference the mower appears to be reasonably robust for a budget mower - better than the Sanli Lawn Beetle�s I have previously worked on however I guess only time will tell.
My experience with Chonda�s to date shows they are reasonably robust and personally I don�t mind mowing with them at all.
One thing that did concern me was the mower was reasonably low on oil � perhaps at half capacity however the oil in the engine was very clean. Note � the mower does not smoke at all, I gave it a good run for 20 minutes or so today after topping up the oil of course.
My understanding with the Honda�s and Chonda�s is the oil level should be checked without screwing the dipstick into position unlike a briggs which must be screwed in to check the oil � It would be great if somebody could confirm.
As usual any comments would be appreciated.
Jaffa J

I picked up 2 of these this weekend just gone, it seems the engine speed on mine is fixed, with no control, the throttle cable is for choke, run and stop positions only. I would suggest its based around a gxv120 as the gcv engines ran an overhead cam.


I wanted to change the fuel on the better one of the 2 I got thinking I would just run it out then replenish, on less than half a tank the engine ran for almost 1.5 hours, while it was hot I also dropped the oil.

They arent a bad engine, shame about the rubbish blade on the good one I got (the other had replaceable blades) and the tiny catcher.... I am pretty sure these were the ones bigW sold for $129, worst case, I sell mine for a carton of beer, then its paid for a good afternoon!

Yes as with hondas, you check the oil without screwing in the dipstick, chances are somone has changed the oil without paying attention to this, therefore they thought it was full

Yep, like Joe said, they are based on the GXV120 and sold under a few different names in some of the bigger dept. stores. Aldi and Masters also sold them under different names. Valve clearance are: Inlet 0.15 +/- 0.02mm ( 0.006 +/- 0.001in ), Exhaust 0.20 +/- 0.02mm ( 0.008 +/- 0.001in )

Thanks Guys, I appreciate the comments. I always like working on something different what I normally find.

Well I gave the carb a good clean, it was full of stale fuel. I also Re roped the starter as the end was frayed and now the mower really runs well.

MrMcKay - you were spot on about the fixed speed, now mine isnt hunting in the low throttle speed position, it is just the same speed until the engine is moved to the stop position. That is slightly strange as the other Chonda's I have worked on before have always had a decent idle.

Secondly mine doesnt have a blade bar, it has to seperate blades on a small long oval type blade disk.

The only problem I had was trying to adjust the valves as the clearance was really low and for the life of me I couldnt loosen the valve bolts like I normally do with 2 seperate spanners. Any tips would be appreciated. I like to make sure the valves are adjusted spot on before moving it on even though its actually running really nicely.

I was thinking the nuts might have some form of loctite or similar on them although no others I have found have been difficult to loosen and adjust.

Jaffa.

Jaffa, remember that the locknut must be loosened with a ring spanner. Trying to use an open end spanner just spoils the nut. This is a good general rule to remember: open enders are special tools for cases where there isn't room for a ring.

It is possible that the lock nuts were over-tightened at the factory, and have not been adjusted since. Never tighten a tappet lock nut to a high torque: it wears and stretches the pitch of the thread, and that makes it nearly impossible to adjust the tappet clearance accurately afterwards. It does not take very much torque to lock them, unless the thread is already out of pitch from the previous tenant's efforts.

You should not be surprised when a chonda runs just as well as a Honda (which means better than any side valve engine): they all do, unless there is something wrong with them.

Thanks Grumpy,

I was most definately using a ring spanner however the nut just would not budge and I was afraid of damaging the pushrods/ valve stem. Is a little heat appropriate in this instance or not? Perhaps another trick.

Note the mower is running really well - the valves are just too tight according to spec.

I'll mention something that I think, and hope, you already know: you always have a ring spanner holding the adjustment nut from rotating, when you are undoing the lock nut with another ring spanner. Use long ring spanners if you've got them, not short ones. In this case, as always when the locknut has been overtightened, you should remove the pushrod before you apply a lot of torque, so it can't get damaged no matter how hard you work on those two spanners, and writhe and curse while you do it. (Just push the valve down with your thumb and rotate the rocker away from it, then lift out the pushrod.) I can't believe you won't be able to get it off that way, even if you give yourself a hernia in the process. If you still can't move it despite breaking the handles off your longest ring spanners, you may have to use heat, but that is a very strong measure: the whole situation is wet with oil, there's plenty more oil in the sump once a fire starts, and then the fuel tank will blow. Please come back and discuss it in detail before you pick up a torch: if it can't be done safely, it shouldn't be done at all. Personally I can't believe it can't be done pretty easily with long rings and the pushrod removed.

Point taken Grumpy, I was only thinking of heat as a last resort, Of Course all petrol and oil will need to be drained if we go down this path.
I will use your revised method above and I suspect with some patience it will come off. Will let you know how it goes in the morning.

Thanks as usual.

I'll propose a refinement, Peter. I would use a six-point socket spanner on the small nut. Six point spanners can deliver far more torque than 12 point ones without damaging the nut. Of course if you have a set of six point ring spanners, you should use them on both nuts.

Grumpy,
Followed your instructions and it worked perfectly. I ended up using a ring spanner (only 12 pt) and a socket on top and it worked perfecty. It took a little fiddling to get the clearances right however they are pretty close to spot on now. The pull start is much smoother than before the valves where adjusted.

The mower starts first pull and runs very smoothly. I gave it a good run last night (no smoke whatsoever) so its ready for a new home. Well most likely a small townhouse to ensure the small thing isnt too overworked. I have included a final photo below, note the very small catcher. I was pretty lucky to find it undamaged.

The chonda base engine is capable of running as well and as long as a Honda, Peter. I make no comment on the mower, though: chondas can be found on some pretty awful bases, I don't know if yours is at the better or worse end of the range.

The main reason to never overtighten a valve-adjustment locknut, is that you stretch the thread out of pitch, and it then becomes extremely difficult to adjust the clearances accurately, because right at the point where you want the adjustment to be, the thread suddenly goes out of pitch. Of course the out of pitch condition exists in both nuts as well as the central screw. When I was a kid all cars that I came in contact with had manually adjusted valve clearance (hydraulic lifters came much later) and the cars I worked on were always pretty old and had been treated pretty badly. I ended up thinking that adjusting valve clearance was a really difficult job. Of course it isn't, when you work on a well made engine that hasn't been abused. In the current case, the abuse probably happened in the factory.

In reality though, life can be more complicated than that. I once towed a caravan around Australia with a brand new diesel 4WD. I ran it around the local mountains first, just long enough to have a first service from the dealer before I left. When I got to Darwin it needed an oil change, so I crawled under and applied a cheap 3/8" drive socket to the drain plug. No success: just ripped the points off the socket, at probably 80 lb ft of applied torque. Mildly miffed, I bought a good quality long-handled ring spanner from a speed shop and tried again. No joy: spanner was fine, but I just couldn't pull hard enough. We are probably talking 100 lb ft or so. Determined to succeed, I applied a double-compound lever system, using various crow bars I had, and really swung on the end of the final lever. It came loose with a horrendous bang, and I changed the oil. When I got home I went to see the dealer's service manager about the matter - it was a cast aluminium sump, and it seemed like a miracle that it had survived the drain plug being done up to more than 200 lb ft. The service manager looked slightly embarrassed, and told me that a few days before my car was serviced, he had noticed that the sump plug on his identical diesel 4WD was leaking, and he had ripped the service tech's arms off and beaten him about the head and shoulders with the wet ends. Then my car came in for service. Guess what the service tech did to my car, as a sort of protest?

I'll close this thread.