Hi,
I have been using new generator since last three months. it is JASCO DB-3800 3.2KW 8HP.
Two or three weeks ago I got a problem. once in a while it takes hiccups momentarily for less than a second and then comes back to normal. This happens on load, without load, on petrol, on gas, when engine is recently started or any time it can occur.
Yesterday I opened its head to clear doubts. I found it carbonized all inside. exhaust valve seat was not shiny as it should be and its stem was also little carbonized under valve head (side nearer to piston) it was little sticking in valve guide. May be due to this valve is not properly seating and leaking.
I cleaned it thoroughly all inside parts, piston top etc. and gave little lapping and polishing on exhaust valve.
My question is what could be the reasons, only in three months it became so carbonized that started sticky exhaust valve?
I am maintaining it well. oil change on time etc. air filter cleaned two times in three months. every 15 days oil change ( approx 80hrs of usage) Oil: caltex havoline CNG.
What is the best oil for my genset ?
somebody recommends to use castrol gtx which is little thick and suitable for gensets
What is the best way to clean up/service head and piston carbonized? is there a cleaner solvent/de-greaser for head service so it does not gets scratched ?
specially the area under valve seat going to exhaust (and on intake valve going to carburator side) is very hard to reach for cleaning.
Also suggest the tappet gaps for my unit on CNG
originally I found exhaust 0.04mm and intake 2mm which i think was not OK so I adjusted them to exhause 0.15mm and intake 0.10mm are they fine?
please reply