Lister CS 6/1 can not reach full load

[Tijean]

In addition to AdeV's list I would add poor spray and leaking injector. That can cause knocking and roughness. Check spray pattern. I would say it be a must to check connecting rod big end bearing clearance; sometimes they do not start out right from the assembler. There are a few people here on the forum that have had these bearings go out or come loose. I dont know how many hours on your engine but if the timing is only 14 deg. advance it is a fair bit less than standard and I would want to check the condition of the injector pump tappet roller to make sure that wear there is not the cause of the timing delay.

[ronmar]

Spill timing 14 degrees BTDC is a little retarded.  19-20 BTDC is the norm, but it also can be a little tricky to measure.  19 degrees of spill timing actually equates to an injector firing around 1 degree BTDC, so if your 14 degrees is accurate, your injector is firing well after TDC...  With timing that retarded, it shouldn't be knocking. I would first look at mechanical interferences as suggested.  To add to the list, check your GIB keys.  A loose flywheel can sound like knock as the crankshaft decelerates under compression and accelerates under combustion...

The 6/1 is rated at around I believe 4.4KW.  That rating can be misleading.  That is 4.4KW of mechanical energy at the engne.  With drive and generator losses this equates to around 3.5KW of electrical load on the driven genset, which you discovered is about the max your engine can sustain...   

[doandevil]

these are the picture of my engine.........i used a dial gauge to identify the TDC and i believe there no mistake with that point. I marked on both the engine block and flywheel for timing later. Today i checked again and still hear the "knocking" noise, i was confused i don't really know where did it come from ?

I heard the sound from somewhere in cylinder head, not in the flywheel, i am sure about this.
i opened the injector and check...there was no leak. The GIB key is alrite, still very tight. today i used a clamp meter to measure the amper in the load bank and badluck it was just 3Kw now.

I am just a newbie with Lister so there are many i still don't know. Please forgive if i ask too many question.