I purchased a Holzforma G395XP chainsaw, it is a Chinese clone of the now discontinued Husqvarna 395XP It is a relatively old technology carburetted engine without stratified intake and without introducing electronic auto tune, a 30 year old design.
Some of the fasteners used to hold the top cowl down were noodled and would only work with a plain slotted screwdriver. They were replaced with hex button head screws.
In the light of experience with Holzforma / Farmertec G372XT chainsaw – early evaluation, a decision was made to preemptively vacuum and pressure test the G395XP saw.
It failed the vacuum test, not really badly, bad badly enough to warrant repair.
On removing the clutch etc to visibly examine the PTO side seal, the outer lip was not properly sitting on the shaft, the seal need to be driven in 1.0 to 1.5mm further. Given that the seals in the G372XT failed early due to one of both of low quality seal material and dry installation, the seal was removed and replaced. It was actually ok, not burnt, not worn, but had not properly engaged the shaft.
The flywheel was removed and the seal inspected, same problem but worse… the seal need to be driven about 2mm to properly engage the shaft. For the reasons given above, the seal was removed and a new one fitted.
A vacuum and pressure test was performed after 10min of operation with the new seals. There is a very slow leak of both vacuum and pressure, so slow as not to be concerning. It is substantially improved over the original hardly used crankshaft seals which were probably just not driven in sufficiently.
However, reassembling the muffler resulted in the M6 bolt thread stripping at just 6Nm (Husqvarna specified torque is 10-12Nm, hinting grade 8.8 fasteners), hinting low grade bolts on the Holzforma. A bad design where the expensive part (the bolt) fails before the nut.
They were replaced with Husqvarna bolts, and new nuts.
Lessons learned
Some small problems, though the air leak (bad crankcase seal fitting) could quite quickly cause a hot seizure which would probably write the saw off.
I own two Holzforma saws, and both failed a crankcase vacuum test. I would probably not buy one again, but if I did, I would perform a crankcase vacuum and pressure test.
I would be reluctant to torque any fasteners to more than 50% of Husqvarna’s recommendation.
Evaluation post repairs
The saw starts easily, as easily as any big saw. After adjustment to service manual settings, idle is stable, WOT is stable. It is a heavy but powerful saw with it seems a moderately wide power band. Running on 50:1 Amsoil Sabre and Ethanol free ULP, it is fairly low smoke, not as clean as strato engines, but pretty good.