Registered: 1431961605 Posts: 2
Reply with quote
This was a conversion I did a few years ago, that worked perfectly up to early this year. It is an aluminum adapter conversion on an AllPower APGG4000, with GX200 clone.
It used to start on second pull after a long prime, everytime. Then it became increasingly difficult to start, but eventually would. We had an extended outage this past March and I ran the genny for 3 days. I had to do an oil change and the unit just would not start after I was done. I had suspected valve lash, so I did an adjustment (many adjustments) and it finally seemed back to normal. After not testing for a few months and now that it is cold, I am having difficulty. It is hard to start and run on NG, but not gasoline. If I adjust the A/F from load block, I can get it going, but it is unstable. After shutdown, I am back to the hard to start condition. I have to re-adjust the load block bolt. I also noticed that the two vents on the sides no longer cut off gas flow when I plug them with my fingers. This used to be the case. I also always had to start with choke open and run open. I also noticed that the engine did not change speed with choke open or closed. The gas supply I am using is for a gas powered pool heater. Very oversized for this application and worked flawlessly up to early this year, I am starting to think that the KN regulator is not working properly. Your input is appreciated.
Registered: 1303240403 Posts: 732
Reply with quote
It really sounds more like a weak spark to me. It takes a much stronger spark on natural gas than it does with gasoline (and starting fluid). When you press the primer button it forces the regulator open and allows fuel into the carburetor. So it should start even if the regulator was bad if you have good spark and are not flooding the engine with to much fuel. I would also try no prime and then keep increasing the amount of prime by 1 second and see if it will ever start. As far as the spark it is controlled by the TCI and Magneto. There is a magnet on the magneto that is prone to rusting. If it does have rust on it that can weaken the spark. I generally take a wire brush and any kind of rust removing spray and clean that magnet. If the magnet is clean then it could be the TCI getting weak. You can try a hotter spark plug than the stock one to combat this if you do not want to replace the TCI (regapping the new plug to .020" as you mentioned can help a bit too). There isn't much to the KN regulator that can go bad unless the diaphragm gets a hole in it but then it will not work at all because the diaphragm will then not collapse and allow the regulator to open. If you would like to send your KN regulator in to us we can test it and see if it is bad or not. __________________ Thank You Senior Technician USCarburetion, Inc.