New Robin Subaru Generator!

I bought a used Robin Subaru R1700i generator. I have no experience with generators. It starts right up, first pull, and seems very quiet.

My question is, when it is sitting there in either power save or non-power save mode, it revs up and down rythmically. "rrrrrrrRRRRRrrrrrRRRRRrrrrrRRRRR"

Is this normal? Its a good quality 4 stroke motor, with an inverter, if this helps.

Thanks,

Jason

[Wavery]

Originally Posted by jchmel9719

I bought a used Robin Subaru R1700i generator. I have no experience with generators. It starts right up, first pull, and seems very quiet.

My question is, when it is sitting there in either power save or non-power save mode, it revs up and down rythmically. "rrrrrrrRRRRRrrrrrRRRRRrrrrrRRRRR"

Is this normal? Its a good quality 4 stroke motor, with an inverter, if this helps.

Thanks,

Jason

If you don't have any load on it, the RPM should stay constant. In power saver mode, it should stay at a very low RPM (idle), just like when your car engine is idling. In non-power saving mode, it should stay at a constant, high RPM.

Whenever a load is applied in power saver mode, the RPM should raise just enough to meet demand then stay fairly constant. If it is in non-power saving mode, you should detect the load but the RPM should stay fairly constant.

It would be interesting to plug in a 100W light and see if that evens out the RPM under load. If it does, it may just be a non-critical electrical problem with the electronic throttle control on the inverter.

It could have a vacuum leak in the intake (under the carburetor). It could have bad or old gas in it.

If you haven't already done it, dump out the old gas and old oil. Put in synthetic motor oil and regular gas (don't use premium). If it still does it after running for about 30 minutes (to burn any residual fuel), spray some WD40 at the base of the carburetor and see if that changes the RPM. If it does, tighten the intake screws slightly (don't over-tighten them). Try the WD40 again and see if that cures it. If it doesn't, you'll have to replace the carb base gasket.

If neither of those remedy the issue, the carburetor float level may be off or the carb float may be bad. That's just a matter of removing the float bowl and adjusting the float, cleaning the needle valve and reinstalling the float bowl.

If the generator sat for a long time with old gas in it, the gas turns to varnish which does not burn. As the gas evaporates (over a long period of time), the varnish coats the float, hardens and makes the float too heavy when you put new gas in. The heavy float will sink lower in the bowl and the needle valve will allow too much gas to enter and the engine will rev as the gas spills into the intake. If the float is too heavy, it must be replaced. The varnish will not clean off.

As always,thanks!

I will do all of the above on tuesday.

I played with it a little more and if I add just a little choke, the problem corrects. So restricting airflow just a tad fixes it. I have the air cleaner off at this point. I wonder If the filter might restrict airflow enough to fix it?

[Speckul8r]

Locally, my friends and I have found that Ethanol gas causes many problems in small motors. i.e. lawnmowers, chainsaws and generators. This has even been a topic of conversation at the small engine repair shops. Everything from eating the fuel lines to causing gunk build up in the fuel tank. So we've stopped using it. There are a couple of places we can get non ethanol gas plus some of the marinas sell it, although at a greatly inflated price. Since switching over a year ago, I've had no more issues that are gas related.

[Wavery]

Originally Posted by jchmel9719

As always,thanks!

I will do all of the above on tuesday.

I played with it a little more and if I add just a little choke, the problem corrects. So restricting airflow just a tad fixes it. I have the air cleaner off at this point. I wonder If the filter might restrict airflow enough to fix it?

Did you have the air filter off the whole time that it was doing that?

If you did, it ~could be possible that the electronic throttle could be that sensitive (but I doubt it).

That's an indication of either a vacuum leak or the float level is too high (instead of too low), which would be rare but easy to fix.

If the air filter of WD40 test doesn't work, let me know and I will try to walk you though adjusting the float level.

I was just thinking.........a partially plugged fuel filter could cause that also.

A picture of the carburetor would help.

My list tomorrow:

New plug, oil, gas, clean gas filter, then run for a couple hours. If my throttle problem persists, WD-40 test.

I will update.

Thanks for the help so far.

Jason

Ok Guys, I did my list of "possible" remedies for this problem, and I know you would have helped me dig deeper, but I got frustrated and called my local small engine mechanic. He found "water in the bowl," and now it runs perfectly.

Thank you for helping me with this as far as I was willing to take it myself.