Getting Roxie Back on the Road

[Blur911]

Time for a short update. I found out why the compressor wasn't building any pressure, the piston ring was smeared and busted. I tried contacting the company, Hadley, but no reply and no kits in stock anywhere, so I have a VIAIR on order.

I wanted to change the oil, but found the filler hose was busted. Got a new one.

Filled her with Mobil1 Truck and SUV synthetic oil, should be decent stuff.

I also installed a new universal windshield washer tank and pump, kinda small, but looks ok. This is the point where I found out the switch is busted and needs to be replaced.

 

[Matt Colie]

Burl,
I do not believe that it will do any harm. Lube oils today are so very much better than they were not too long (in my terms) ago. Time was that I would never have used a 5W - Anything because of an issue called "Shear Down" that cause lube oils to loose some viscosity with use. From the reports I get from Blackstone I am not seeing evidence of this.
So, if someone says 5W30 is too light for a 455 coach, just smile and say "I'll take my chances".
Matt

 

[Blur911]

Burl,
I do not believe that it will do any harm. Lube oils today are so very much better than they were not too long (in my terms) ago. Time was that I would never have used a 5W - Anything because of an issue called "Shear Down" that cause lube oils to loose some viscosity with use. From the reports I get from Blackstone I am not seeing evidence of this.
So, if someone says 5W30 is too light for a 455 coach, just smile and say "I'll take my chances".
Matt

Yeah, I have no qualms about the oil, it's all good stuff. So 5W30 is applicable, I'll keep the 20W50 for air-cooled.
I'll keep an eye on levels if I ever get her out of the backyard, I'm old enough to remember when engines burned oil, it's just a matter of the rate.
I guess some new engines come with 0W20, not a good idea, it's all about CAFE ratings and engine longevity is secondary.

 

[Blur911]

I'm definitely upgrading the compressor with this thing.
Now I need a new mount, I could just weld on some 1" angle and drill 4 holes, or I could make a bolt-on plate with spacers. Opinions?

 

[Matt Colie]

Burl,
That should work out just fine.
If it is a 76, the compressor is in the rear. Why not just screw it down to that shelf?
That is what others have done.
Out 73 has the pump in the front. I have a local metal supplier and I am just going to get a 100X400 piece of 3mm aluminum to bolt over the old mount and call that done (once I get the heavier wires in place).
Matt

 

[Blur911]

Burl,
That should work out just fine.
If it is a 76, the compressor is in the rear. Why not just screw it down to that shelf?
That is what others have done.
Out 73 has the pump in the front. I have a local metal supplier and I am just going to get a 100X400 piece of 3mm aluminum to bolt over the old mount and call that done (once I get the heavier wires in place).
Matt

Because nothing is stock on mine, it's up front too. I'll mount it to the same bracket, but it's longer and needs modification, hence either a plate, or welded on angle at either end

 

[Blur911]

I'm making a plate to bolt the new compressor to. I was going to mount it with 5/16" bolts, then realized I have a lack of standard nuts and bolts, everything else I have is metric and I have lots of that.
So, should I keep Roxie standard, or use the 8mm bolts I have in my hand?
Also, should I also put rubber washers under the stand-offs for additional vibration/noise isolation?

 

[pvfjr]

So, should I keep Roxie standard, or use the 8mm bolts I have in my hand?

That's a predicament for sure. I'm always tempted to use what's on hand and save the trip to the hardware store, but I think I'd make an exception for this. You won't find any metric stuff on my GMC, since I prefer to carry fewer tools. I've got other vehicles with standard engines with metric bodies, and I find it quite annoying to always be forced into carrying both sets of tools. With storage space at a premium, I try to keep the tool set pared down as much as possible.

 

[Blur911]

Compressor is in and working. I'll fire up the old beast in a bit and see if the high pressure switch works ok, I have no idea what it's set for.

Fuse and relay on the other side.

 

[Blur911]

I have put the quest for window rubber on the back burner. Driver's side rear window had migrated rearward and the rubber was out and there was a large gap.

So, after letting it sit in the sun all morning, I took a soft-faced hammer and a piece of wood and whapped it back into place . Looks ok now, I'll tackle the rubber shrinkage problem later, priorities.

 

[Blur911]

Next up, driver's side airbag looked a little scary.

So, newer one went in. Job wasn't too hard, all the nuts moved ok.

 

[Blur911]

Original Onan needle is on the right, new one doesn't even fit in the hole. Kit cost me $37USD and probably the same amount to get here. Should have just bought the gasket I needed.

So do I have an oddball carb...or is it the wrong kit?
It says K1-LMB on the bag.

 

[boybach]

So, after letting it sit in the sun all morning, I took a soft-faced hammer and a piece of wood and whapped it back into place . Looks ok now, I'll tackle the rubber shrinkage problem later, priorities.

I'd open up the gap again, squirt in some good quality polyurethane and knock it back in place. Then forget it. Fixed.

 

[Blur911]

I installed the carb on the Onan and tried to get it started, that's when I found out there was no spark. Traced it to points that were never set up correctly, it could never have ran as the points never closed. Adjusted by mirror, filed a little, now I had spark.

Couldn't even get a sputter out of it until I held the choke off and took off the air filter hose. Then the occasional sputter, got better, but died as soon as I let go the starter switch. Finally I hot wired +12 to the coil and it stayed running, not perfect, but running ok.
So I guess a relay isn't pulling in, or making contact, or something similar, will check tomorrow. Glad it runs though.

 

[Matt Colie]

Burl,
This is why most of use have installed a flywheel triggered Pertronix. If you do, set up an extra 2° because the push rod set was soo bad that Onan had to retard that far just to be safe.
The control boards are know to be an issue. There is a good replacement available from someplace.
Matt

 

[boybach]

Congrats on sparking her up. We all had issues at first, but a bit of tinkering and you'll have her running smoothly for sure.

The way the choke works is interesting. It goes on when the engine is cranking, then as soon as she fires up it immediately pulls off.

Keep going!

Larry

 

[Blur911]

Burl,
This is why most of use have installed a flywheel triggered Pertronix. If you do, set up an extra 2° because the push rod set was soo bad that Onan had to retard that far just to be safe.
The control boards are know to be an issue. There is a good replacement available from someplace.
Matt

Pertronix upgrade is on the list, but for now trying to get what I got going. Will change the oil and filter and check out the electrical ASAP. Also have to find a new air-filter and inspect/replace the intake hose
BTW, what's the chosen oil flavour for the Onan? I have a filter.

 

[tmsnyder]

Burl,
This is why most of use have installed a flywheel triggered Pertronix. If you do, set up an extra 2° because the push rod set was soo bad that Onan had to retard that far just to be safe.
The control boards are know to be an issue. There is a good replacement available from someplace.
Matt

That still won't give any spark control, it's fixed at something terrible like 15* . This is why there's so much unburned gas in the exhaust on these genny's, at rallies it's been described as unbearably fumey in the campground when there are several GMCs running their generators all at once.

I bet these would run great on a Speeduino fuel injection system with spark and fuel control. That would be the way to go. It's on my list of things to do, however my list only seems to grow over time, never decreases. But that may be normal from what I've heard.

 

[RF_Burns]

That still won't give any spark control, it's fixed at something terrible like 15* . This is why there's so much unburned gas in the exhaust on these genny's, at rallies it's been described as unbearably fumey in the campground when there are several GMCs running their generators all at once.

I bet these would run great on a Speeduino fuel injection system with spark and fuel control. That would be the way to go. It's on my list of things to do, however my list only seems to grow over time, never decreases. But that may be normal from what I've heard.

Check out this guys Youtube channel. He puts a couple different small single cylinder engines into a small car and see's how fast he can get the car to go. At some point he adds EFI from a kit, then updates to Speeduino. It's very entertaining.

Wally added EFI to his Onan.

 

[Matt Colie]

That still won't give any spark control, it's fixed at something terrible like 15* . This is why there's so much unburned gas in the exhaust on these genny's, at rallies it's been described as unbearably fumey in the campground when there are several GMCs running their generators all at once.

Todd,
There is apparently something you don't know about engine controls.
Constant speed engines like generators do not need any advance curve at all. Even with the varying loads, there is no requirement for changing the ignition timing.
And yes, the guy we had in from Onan told us that the push rod ignition was so unstable that durability required that they retard the timing about 2° from MBT to stay safe. So, if you are going to flywheel trigger, you can put that 2° back in and the unit will run better for it.
Now all we need is a good CDI to kick those plugs. I'm hoping to use one off a moped.
Matt