The generator produce onely 73 volts ac on the 120 volts plug and 146 volts ac on the 220 volts plug . what could be causing this problem

First, I'm not a Coleman Tech.
* First check the generator for a wire(s) output description. This will confirm what each wire is producing and where it should be connected to.
* The specs will also give you an idea of what to expect from a particular generator. (Don't expect 220Volts from a 120 Volt small generator.. Hence the 120 VAC generator will only have 3 wires instead of 4 wires for a 220-240 Volt generator. DC/AC generator will have 5-6 wires.)
* In general, on/off switch on the electrical part of the generator (the actual electric source) is on once the engine is up and running. Electricity is being produced at this time. The on/off switch is usually the main electrical breaker that is rated for the full output of the generator. This is very similar to your house breakers except for a modification of the hook up terminals used to wire in this safety component. Like most breakers there is an input(s) then output(s). Usually the input lines will be black, white, with an additional green wire that is also connected to the frame of the generator. These three wires will hook up to one side of the breaker or the "Line In" side or "L1,L2" The other side of the breaker should have been hooked up directly to the 1 or 2 duplex (120VAC) outlet panel.
* on larger generators that produce 120/240 VAC 1PH (two 120 volt AC outputs with alternative 220-240 volt AC) There will be an additional wire that may be the same or different color IE; 2 Blacks, Reds, or Blues. This is hooked up in similar fashion to the breaker except there will be an additional section to the breaker or even two single breakers stuck together with a bar across both switches. (again similar to a 220 VAC breaker used in a house panel.) The extra wire will go to the 2nd section of the breaker. The other side or "output" of the breaker will be wired directly to a set of Duplex outlets (a pair or 4 outlets) AND a 4 pronged 120/240 1PH outlet "Twist Lock" style. (though you may find specialized outlets for single purpose generators.)
* Larger generators may also have a DC (12 or 24 VDC) wire which is of a different color from the AC wires. Expect it to be Black, Red, or White. (Black or white is probably the negative with the Red as positive.) If you do have DC wires then it's more than likely the AC wires are of different colors to avoid getting the DC mixed up with the AC side.
* Final; check your warranty. Have your vendor or MFR perform a service and annual maintenance check which is a good idea as they can change out your air and fuel filters. Check and clean the spark plug. Make sure everything is working properly. The peace of mind is worth it.
Aloha, ukeboy57

as 240 volts is single phase , it will not be possible to reduce the power by cutting across a neutral wire ( 240 volt power out and 240 volt neutral return That is ac power ) to do what you want to do you will need a 3 phase generator so that you can jump across a phase to get lower power

Have you tried flashing your generator? Sometimes the magnets in the generator loose their polarity. Google and YouTube "flashing a generator"
HFLASHING the GEN

Sometimes the magnets lose their polarity. This worked on my brothers $1200 gen. Its worth a try. Good luck!
Check all wires/connections first, Then try this-
(Remove spark plug wire first!)
To flash the field on a small home use generator, get an ext. cord & cut off the female end of it & strip the wires & connect the wires to a 12 volt car or lawn tractor battery, & plug the male end of the cord, into the 120 A.C. side of the generator.

Make SURE that the black wire which is POS/HOT on an A.C. cord, gets connected to the RED/POS. side of the auto battery, & the white wire on A.C. cord gets connected to the BLK./NEG. side of the battery. If the ext. cord wires are not black & white, then the smaller prong of the plug is the POS./HOT

Plug the other end of the ext. cord into the generators 120 volt side (**remove spark plug wire**) & pull the starter cord 4-5 times, then remove the ext. cord, reconnect the spark plug wire, start the unit & plug something of 120 A.C. volts in to see if it works. Then let it run for about a half hour with 2 - 150 watt lights to help re-generate the unit.


Read more:http://www.doityourself.com/forum/outdoor-gasoline-power-equipment-small-engines/188605-recharging-generator-field.html#ixzz29QwjlAOWere's one way-

You cannot, speed is propertional to voltage on these, as they have capacitor voltage regulation. Do not use this for powering home appliances, it is common to see this design and not a problem. If you add load and it will decrease but so will the frequency

Inverter Generator Benefits

• The EU3000 series generators are inverter generators. The generator features an alternator, which produced high-voltage, multi-phase AC power. This power is converted to DC power and then converted back to AC. This process is controlled by a microprocessor and is necessary to provide stable, consistent power capable of running equipment sensitive to power surges. This type of generator provides higher fuel efficiency and lower operational noise ratings in a lighter model than home and work generators produced by Honda.
  

EU3000i Handi Specifications

• The Honda EU3000i Handi is a 3,000-watt inverter generator that features wheels, folding handle and a recessed convenience light. The engine is a Honda GX160, which features a 163-cc displacement. The AC output is 120 volts, with an average rating of 2,600 watts and a maximum production of 3,000 watts. There are three receptacles to include a 20A, 125-volt duplex and a 30A, 125-volt locking plug. The DC output is 12 volts and 100 watts. The EU3000i can hold 1.56 gallons of unleaded fuel, which will provide consumers with 3.6 hours of run time at 25 percent load for 7.7 hours.
  

performance chips of BMW.

Hello, First figure out what the load per leg is on your generator. Are you using the 240 Volts because this is two 120 AC volts legs and they are 120 degrees out of phase with each other.

You will need to figure what the power factor is for each phase on this generator. To figure the power/wattage by using ohm's law. Voltage times Current will give you Watts. Example: If the generator is generator 240 volts the maximum current available is about 23 amps. The maximum current for 120 volts will 46 amps. Therefore, the maximum current per 120 volt circuit is 23 amps for one circuit and 23 amps for the second 120 circuit..

I would try replacing the circuit breaker with the same amperage breaker. Also, watch what the generator load is per circuit. You can install current meter for each circuit. This will give a good indication of which circuit is pulling more load than the other circuit. GB...stewbison

Please understand that the generator produces power from fuel with an engine wheras the invertor is one which genrerates power from a stored battery using the principle of frequency switching a DC source to induct and produce AC.
Now you can have an uninterupted power supply setting with the invertor backed up by the generator so that when the battery voltage goes down you can start and charge the invertor and also supply the extra energy .
the ratings of both must also be considered.

First of all it is possible that the is no power going into the inverter,trace the input source to see if the connection from the generator is ok. check the fuse if it is broken if not, the contactor or switching relay in the inverter is bad

as a general rule ,only if your ac was a window unit. aka a 120 volt unit . all other acs use 240 volt. a 120 leg and a 120 2nd leg to equal 240, so there is really no common. what kills acs with a generator is the lack of watts and starting torque. an ac (3 ton) and up needs a generator of 10000 watts minimum to handle starting trque. they also need a hard start kit to boost starting voltage.for god sake someone reply and tell me what a good job i am doing!!!!!!!as in grade the response to your question.

no!   It will be ruined if you try that.