[ericstromberg]

So I am in the process of cleaning the carb and resealing the intake manifold on my 420. I have a few questions I hope someone can answer.

Onanparts.com is on a fishing trip until Sept. 2. Any back up recommendations? I have found some parts at some welding supply companies (Onan p220 used in a lot of Miller welders), but I'd just as soon give the business to someone here on the forums or affiliated with them.

I removed the idle mixture adjustment screw to soak and clean the carb, but I haven't found any mention of an initial setting when I replace it. The manual I have refers to the EPA version with the plastic head and preset from factory BS. Can someone give me a ballpark # of turns out from seated to give me a starting point?

While not fuel related, I also have some starting issues. Sometimes, the starter just clicks, but doesn't spin. It may do this a few times before it engages and turns the motor over. Is this likely a starter issue or en electrical issue? I know that the ignition voltage goes through a bunch of safety switches on its way to the solenoid. Am I just getting too much of a current drop to throw the bendix out fully sometimes?

Thanks for the help!

 

[bob421]

Eric,

Give Boomer a shout, he has most parts, very reasonable and he knows Onan's.


[email protected]


Bob P

 

[boomers_influence]

bob
thank you.
eric did send me a p.m..
boomer

 

[wmgeorge]

Clicks and won't pull the starter in is not a safety issue, do a search for "starting improvement kit" it adds a relay and some minor wiring changes.

 

[chuckv]

Eric,

Like Bill says the starter improvement kit should help with the accumulated voltage drops of the long series circuit of safety switches and two passes through the key switch that the solenoid power takes in the factory wiring layout, seen here:

If the key switch is original to the tractor, you should replace it as well. Also check the mating plug contacts for signs of heat or corrosion damage that can cause added voltage drop.

Here is what gets changed schematically when you add the relay of the 'improvement kit" and as you can see it uses the relay contacts to directly power the solenoid terminal "S" when the control voltage on the #700 purple wire is hot (key in the START position.)

Chuck

 

[wmgeorge]

And PS, those relays are nothing real special, you can get them at any good auto parts store. No don't ask for the John Deere relay, I forget the part number but its something like a 30 amp rated, normally open 12 volt DC relay. As I recall they are $7 - $10 or so. Might even have the same terminal numbers as above.

 

[chuckv]

Bill,

Yes the terminal numbers are standardized in the 12 volt/automotive industry. These are called Bosch style relays and available most anywhere. I buy them from Surplus Center when I have other things on order so I don't pay separate shipping -- theirs is under $4 each with socket and wire pigtails attached. Caution though, the wire colors are NOT THE SAME as the Deere kit so watch the numbers when you get it connected.
http://www.surpluscenter.com/Electrical/Relays-Contactors-Solenoids/DC-Relays-Contactors-Solenoids/12-VDC-SPDT-40-AMP-RELAY-WITH-SOCKET-BASE-11-3222.axd

If you are not using the Deere kit ($30 or so...) you need to find the splices and terminals to make the connections. Here is the Deere kit that is pre-wired:

Chuck

 

[ericstromberg]

I ordered the starter kit yesterday. Looking forward to getting this 420 back to good running form. Started to put the carb back together last night and pulled the intake manifold apart and cleaned it. Still need to drill out the rivets. I ordered a tube of Hondabond to make the gasket in between the halves, it's a high temperature oil/fuel resistant sealant/gasket maker. Thanks for the help and advice, guys!

 

[knottyrope]

my 420 will do the clicks only and its always been for me corrosion on the battery terminals or my frame ground was a bit rusty.

battery terminals even looking clean can deceive you as lead corrosion is clear. use a knife to scrape it shiny

 

[ericstromberg]

Well, I got my parts from Boomer (thanks for the extremely quick service!) and got the intake manifold sealed up last night using Hondabond. I drilled the pins/rivets (mine had what seemed like rivet heads, but the other side was cast into the manifold) and replaced with socket head cap screws and rubber stopper lock nuts. Tonight, I'll put the intake and carburetor back on this beast and see how she runs. Once I have her running smoothly, the next step is to tackle the hydro. Surges and creeps. I'm hoping that the surging was due to engine surging and that the creep can be adjusted out in the linkage, otherwise I will probably have to replace some parts in the linkage. I'll be starting a new thread on the hydro work, so feel free to pop in and offer advice. I really appreciate all the help I've gotten on this forum and over on MTF. Great group of folks.

 

[ericstromberg]

I found this relay and wiring on Amazon. Will this work? I figured I can do my other tractors as well. It looks like this relay can be done in a normally open or normally closed configuration.

http://smile.amazon.com/Relay-Harness-Bosch-Style-40AMP-HRNS/dp/B005HFYE1O/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1408987349&sr=1-1-catcorr&keywords=12+VDC+Waterproof+Relay+SPDT+30%2F40A#productDetails

 

[chuckv]

Eric,

Yes that is the standard configuration for a SPDT 12 volt relay (single-pole, double throw -- another way of saying the wiper contact has both a 'normally closed' and a 'normally open' terminal that it switches between depending on if the coil is energized or not...)

Chuck

 

[ericstromberg]

Put the intake and carburetor back on. Took a few turns to refill the fuel bowl, but she started right up. Purrs through the whole throttle range, these Onans have a nice sound.
I ordered some relays on Amazon to do the starter assist, but in putting everything back together, I noticed the main ground is anchored to the side dash tower with the side shield screw. Seems like this wouldn't be very good to ground to. What are your 318/420s grounded to? My 200 series tractors are grounded to the engine, but it seems I need a longer cable for that.
Hopefully, I can get it out and drive it a little tomorrow to assess the hydro.