Your last generator Maintenance Run

[3930dave]

i only work on air cooled stationary units. The type of oil and viscosity vary depending on climate, however a good 5w30 synthetic covers most of the ranges according to generac tech. Personally i use Mobil 1-5w30 on all my services. And its changed out every 2 years on any unit newer than 2010 and every year on older units. These Gen units dont gets much use and build up moisture in any oil. So even if it has low hours, it gets new oil. Were talking about 1.7 quarts after all.

Units with alot of use actually have better looking oil than the low hour units.

Generac had finally introduced hydraulic valves in the lower kw units (13&16 kw). Hopefully soon in the rest. Lately ive been running compression tests on older units as a matter of general service and writing value on valve covers. Better way to keep abreast of generator condition over time. Also a good indication if valve adjust needs to be looked at.

Generac recommends valves at 25 run hours, then every 4 years ish....really depends on use. I have repaired many, many generator start and run issues over the years with simple valve lash adjustments.

I just heard Generac now has a 24kw air cooled unit available. And i thought my 22kw was cool.

The stationary units have a replaceable oil filter ... screw on... I only use OEM filters myself, but purchase 90 at a time from Generac. Napa also sells a good aftermarket unit. But buying 90 at a time i get them far cheaper than napa.

I was in an autoparts store, and overheard 2 middle aged guys debating changing the anti-freeze on a motorcycle (spend the $, or not)..... even picking out boutique fluids, that's the nice thing about small engines..... not much cash involved.

I've used plenty of Mobil 1 over the years (and Castrol, Rotella.....).... unless you get crazy with viscosity, it's pretty hard to go far wrong with any of them.

Good points about moisture....... easy to forget about that, esp. on stuff that sits idle most of the time.....

Rgds, D.

 

[PILOON]

Quote----------Good points about moisture....... easy to forget about that, esp. on stuff that sits idle most of the time.....

That's why a monthly exercising of your genny is important.
Run it 'til hot, preferably under a loaded condition. and you'll eliminate the moisture problem.

I once tore down a 'Cosco' gen set that had over 800 hrs clocked (used by a contractor) and the innards were just like new.
Problem was valve stems had worn down so much that there was no compression at all.
I simply adjusted the valves and it is still giving great reliable service.

 

[TimberXX]

solid advice as always guys. My generac 17 kw manual has oil and filter changes every 200 hours, but I am planning to change every 100 hours, again its cheap. I am surprise about the valve adjustments with so few hours. My honda GXs don't need them until 400 hours. Any issue or risk adjusting valves too often?

 

[grsthegreat]

solid advice as always guys. My generac 17 kw manual has oil and filter changes every 200 hours, but I am planning to change every 100 hours, again its cheap. I am surprise about the valve adjustments with so few hours. My honda GXs don't need them until 400 hours. Any issue or risk adjusting valves too often?

Not that i have ever heard about. Probably 70-80% of the units i check at 25 hours dont need adjustment, but warranty requires a check. Better safe than sorry

 

[daugen]

my last two Generacs, 20 and 22kw, were amazing in their lack of oil usage. I changed oil and oil filter every year with synthetic oil, and air filter every two years, the latter which looked like new. On one four day run, I saw the oil level drop about a third of the way down the stick, but still plenty. I would normally stop the unit during the day, giving wife plenty of notice, let it cool off completely and then start it back up. Found the units to be tremendously reliable.

But....I never adjusted the valves, never had confidence in my doing that, but then I don't think either unit had more than several hundred hours on them.
This is where hiring a pro every few years to do it right has to be the smart thing to do.
Interesting about change to hydraulic valves, that used to be the selling point of Kohler engines vs Vanguard/Briggs. Is Generac now using Kohler engines or did they re-engineer their own engines? I always thought the Generac engine was just a higher spec Vanguard, perhaps with better oil retention rings.

 

[grsthegreat]

my last two Generacs, 20 and 22kw, were amazing in their lack of oil usage. I changed oil and oil filter every year with synthetic oil, and air filter every two years, the latter which looked like new. On one four day run, I saw the oil level drop about a third of the way down the stick, but still plenty. I would normally stop the unit during the day, giving wife plenty of notice, let it cool off completely and then start it back up. Found the units to be tremendously reliable.

But....I never adjusted the valves, never had confidence in my doing that, but then I don't think either unit had more than several hundred hours on them.
This is where hiring a pro every few years to do it right has to be the smart thing to do.
Interesting about change to hydraulic valves, that used to be the selling point of Kohler engines vs Vanguard/Briggs. Is Generac now using Kohler engines or did they re-engineer their own engines? I always thought the Generac engine was just a higher spec Vanguard, perhaps with better oil retention rings.

Generac manufactures their own engines, complete. The new engines are their own design.

 

[3930dave]

Any issue or risk adjusting valves too often?

Excluding one buddy of mine (he can break an anvil, w/o really trying), no real downside to adjusting valve tappets.

Engine off, you manually spin the crankshaft till one set (intake or exhaust) of valves is closed/fully seated. Then using feeler gauges, you check the clearance between the valve and tappet, and adjust as needed. Tappet has a lock-down nut, that needs to be loosened if you need to adjust, then tightened once adjustment is done.

Like tying your shoes, once you do it enough, you don't even think about it, and get it perfect each time. <- That would be somebody like grs...... when I do one every fourth blue-moon, I read and re-read the engine write-up (mostly just getting familiar with the index marks for crank/cam) and slowly go through it. Once I think I'm done, I spin thru a complete cycle again, and re-check all clearances.

If you get a clearance a little off.... no big deal, just re-do. About the only thing you can really mess up, is forgetting to tighten the lock-nut down, or trying to gorilla it down too tight......

Rgds, D.

 

[grsthegreat]

Thats why i use a torque wrench.

 

[3930dave]

Thats why i use a torque wrench.

+1.

Bought my split-beam 3/8" inch/# one, the first season I had my street-bike.

My abridged description was an attempt to de-mystify the process..... once a process is understood, then the failure points tend to jump out.....

Driving one nail with a hammer should be simple.... but I'm sure I'm not the only one to hit his thumb

If you have the step by step process for positioning the valves on a given engine, it's pretty cut/dried. For someone with zero experience, gaining confidence using the feelers is one mental hurdle - mainly because it's outside the realm of day/day fine motor-skills for many folk today. First-timers can relax a bit, once they understand that being 1 thou out just means Wash/Rinse/Repeat the adjust cycle again.

My first time was a Mitsubishi car engine (needed after head repair), many years ago. I'd say the easiest way to get zero-cost/risk experience is find somebody's discard small-engine at the end of their driveway, and adjust that one up.

Like a 5 year old with a computer, it's a lot easier to jump in and play when no $ are perceived .

Rgds, D.

 

[downsizingnow48]

The last engine I adjusted valves on was a 1958 Corvette 283/270hp. That was mamy moons ago. My generators have never shown any need. Just for backup power it will be a very long time for lash to get too much. I always used to err on the loose side. A bit too tight = burned valve seat but a bit too loose = no big deal.