The article documents replacement of the engine on a Deutscher 650 Chipper Shredder. The original engine was a Briggs & Stratton Intek 206 single cylinder four stroke petrol engine which has accumulated 200 hours over 10 years use.
During that time, it had regular oil changes, air filter changes, new carburetor seat and air filter gasket, as well as frequent cleaning with compressed air to ensure the air cooling was fully effective. It passed a leak down test of valves and rings at 200h, then valve clearances were checked and were spot on… no adjustment needed. (Note that the engine was never run on Ethanol fuel.)
Additionally there is ongoing belt maintenance (adjustment and replacement) and blade sharpening / balancing.
Replacement parts were expensive, the seat alone from eBay was over $20, spark plug over $20, the air filter gasket was over $40. Air filter sets were quite cheap on Aliexpress.
It gave good service, and was reliable. Approaching 200h, a decision was made to replace the engine with a Chonda to minimise the risk of failures (like plastic camshaft gears, lobes, compression relief).
Basic fit up
Above is the Deutsher 650 Chipper Shredder.
These small engines tend to copy mounting bolt sizes, shaft sizes, and even overall size to be compatible with other brands for marketing reasons.
IIRC this chipper was available with either B&S or Honda engines, but the Honda was unavailable at the time, so reluctantly I chose the B&S product.
Above, the replacement engine is an Edison (Baumr-AG) 7HP (5.1kW) 210cc engine (similar to Honda GX200) that fitted the chipper chassis’s existing mounting holes, $159 inc shipping. New 304 M8 bolts, washers and nyloc nuts were used. The recoil starter was rotated for convenient starting (why don’t they pack a spare sticker for the recoil start for attachment after rotation).
Above, with the safety cover removed for pics, the shaft and hole pattern were compatible with the B&S, but the holes in the crankcase cover with threaded M8, so two M8 bolts were required for the belt guides shown here.
The pulley was removed with a 5t hydraulic puller, it did not come off easily so it really warranted a puller. Replacement on a clean lightly oiled shaft was easy (using the 5/16UNF threaded hole in the end of the shaft and a threaded rod and nut to push the pulley on).
At 33h
At 33h the valve cover was removed, head bolt tension checked, valve clearances adjusted, and crankcase bolt tensions checked. The only thing notable was that both valve clearances were 0.05mm too low. Exhaust valve clearance is important not just to normal engine operation, but critical to compression relief.
Above is a peek through the oil filler hole at the cam gear. It is obviously a metal cam gear. The oil that can be seen is about 3h after its second oil change, it is quite clean and the sump appears quite clean.
There are a few kinds of metal camshafts available on Aliexpress, all with metal gear are all-metal (no plastic in lobes or compression relief). The following is an example, about $40 inc shipping on Aliexpress.
Improvements
Some changes were made to check / improve the engine for better life / easier maintenance.
Above, the exhaust nuts were removed and reinstalled with anti-seize.
The fuel hose had been cut too short and was precariously attached to the end of the nipple. It was replaced to prevent it falling off and spilling fuel on a hot engine.
Above, an inexpensive hour meter was installed.
Continuing problems
The fuel cap leaks when the chipper is laid over for maintenance.
In conclusion
At 30+ hours, the engine has been reliable, responds better to load than the B&S, and looks promising. It looks to be a good quality engine.
Chonda parts are readily available on Aliexpress, and quite low cost, eg 5 complete sets of Honda GX120/160/200 engine gaskets cost $20 inc shipping.
The B&S engine was in good working order and sold on Gumtree for almost the cost of the new Chonda.