Re: Onan generator difficult to start - electrician suggested a fix -

Porter McRoberts

As a side note on the long runs from the starting battery to generator and engine and the house batteries to the bow thruster, don’t overlook the resistance of simple wire terminal corrosion. The terminals loose their rich coppery hue over time, and the surface area for conductivity diminishes. We all know the amp carrying capacity is a function of cross-sectional area of the wire. It’s all for nothing if the terminals aren’t in ship shape. 
Recently, hunting down the cause for a sluggish to no-start start on our Onan in fiji I simply Emory burnished the all the myriad terminals from start battery to the Onan, through the solenoids to the starter motor. What an amazing difference. From the click click of an underpowered starter to a firm start. With just attention to clean terminals and then some Corosion x.  We Then later also rebuilt the starter for 70$!! and it’s kicked like a mule ever since.   

The corrosion was  minimal to the eye, but mattered immensely. A good lesson for me.

Porter McRoberts 
S/V IBIS A54-152
WhatsApp:+1 754 265 2206

On Apr 12, 2022, at 6:29 PM, Chris Paul via <chris__paul@...> wrote:

Hi JP,
Thanks for your reply.
I think you are right. I will check the battery.
The main engine starts easily, so I thought it was the generator's problem.
I was not aware that the generator requires more cranking power. 

Hi Mark,
Thanks for your reply.
If I started the generator yesterday then it would start reasonably easily today.
If I did not start either engine for a week then the generator would struggle and sometimes not spin fast enough to start.
My method to start the generator was to start the Yanmar first.

So I am assuming the generator should start easily with a "good" battery and extra cables should not be required. 

Regards, Chris Paul (0427788800)

On Tuesday, 12 April 2022, 04:42:40 pm NZST, Germain Jean-Pierre <jp.germain45@...> wrote:

Both the main engine and the Onan are started from the same battery. Hence the note in the owner manual paraphrased as “ if the start battery is low, start the main engine”. 

Because the compression ratio of the genset is much higher than the Volvo or Yanmar. Look at the power output of the battery; it may be suspect. 


Jean-Pierre Germain, X owner ofEleuthera, SM 007. 

On 11/04/2022, at 21:08, Chris Paul via <chris__paul@...> wrote:

I have owned Glazig SM352 for about a year.

The Onan has always been much more difficult to start than the Yanmar.
This is particularly so if the starting battery has not been used for some time.
Do other SM owners have this problem?

Recently I spoke to an electrician and he suggested I connect the Onan to the Yanmar with 35mm starter cable.
This essentially doubles the starter cable size (for both engines) without opening the engine room seal. 
I am interested in the thoughts of other Amelians.

Chris Paul
SV Glazig
Currently in the bay of Islands, NZ

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