Monday, May 19, 2014

Smarter Tools 2000W Propane Conversion


I have been wanting to have generator I could take camping or use in a power outage, but I hate to have a gasoline can in my auto and I hate having to store gallons of gas in my garage – a hazard in case of fire and a something that degrades over time.
I’d heard about tri-fuel conversions and that seemed to made sense. I already carried propane with me when camping and it is easily available in most camping areas. Plus, its storage life if much longer compared to gasoline. On top if that, I do have natural gas at my home, which has never gone out and is available in a power outage.
I settled on a 2000w because as ~45 pounds this was as big as I wanted to lug along. I really wanted a Yamaha or Honda, but their prices are twice what their clones are and I didn’t plan to use the inverter very often.
 
I started with a Ramsond unit at $400, but it leaked oil and was much louder than the Hondas that it clones, so I sent it back. I found great reviews for the Smarter Tools 2000W that Costco sells for $600 (there is also a 2000i unit they sell at some stores). It has a genuine Yamaha MZ-80 engine in it; the rest is built in China.
 
It goes on sale about once a year and I bought it at $550 – about $400 cheaper than the lowest price I found on the Yamaha and it did come with the Costco 100% satisfaction guarantee. I ran it on gasoline for two hours (don’t forget oil) and found that it started easy and if it was any noisier than the Yamaha or Honda, I couldn’t tell.
Ordered the Motor Snorkel conversion kit from US Carburetion for about $200, gathered my connecting hoses and pipe fittings and gave it shot. I am, at best, only modestly handy and have never tried anything like this before.
The front plate is initially hard to remove; so hard I was first worried about breaking it, so I actually lightly lubed the connection points with a bit of silicon lube; it helped.
 
I disconnected the bolt to the lower right of the air cleaner and took off the air cleaner plate. As it turns out, you don’t need to take the plate off (except that it may make the air intake assembly just a little more flexible to work with) and there must be an additional bolt on the rear of the air cleaner you can’t access from the open side. Opening the rear side seems to be a chore, so I decided to see if I could flex the part far enough away from the gasket at the carb to add the snorkel without removing it. Yes, it works, be careful.
There are two bolts to take off the gasket assembly. The front bolt was easy; the back bolt was a pain to get to. Very little room to work with. A standard 1/4 socket was too short, a deep socket too long. I daisy chained together a flexible connection (see pic). But you may find some other combination that will work.
 
When I pulled back the gasket frame there was a wide, black, rubber gasket and a very thin gasket between the cleaner neck and the carb. A post on the US Carb forum informed me NOT to remove the larger rubber gasket, as that was a part of the tube that goes to the air cleaner. I would have missed that if I had not asked.
I also noted, with great concern, that the MotorSnorkel face was shaped very differently that the face of the carb inlet (see pic). That seemed wrong, but US Carb said it was right. I did put the very thin gasket back on (after these pictures), between the snorkel and the carb face, because I was worried about a tight seal (and I had the room).
 
 
 
The snorkel did fit the carb hole and bolts and I carefully tightened it down. Instructions say to tighten it snugly…but what exactly is that? I know you can’t exactly torque wrench it. So, you can see how tightly I tightened it by the distance of the bolt end in the nut. I basically tightened it until it stopped at a modest amount of pressure.
 
The next problem was running the hose out of the case. I planned to install the regulator on the removable plate, so it was easiest to run it out on that plate. In the lower right corner there is a small triangle where there is no soundproofing material on the cover plate and that seemed an obvious place to drill for a hose exit. I decided NOT to use the 1” grommet supplied with the kit (too big) and simply drilled a hole large enough for the hose. I know I will need to inspect this occasionally for wear.
 



I decided to install the demand regulator on the removable plate. The front of the inverter has the controls and the regulator would be in the way there. The rear is the exhaust and that seemed like a really bad idea. To attach on the far side I was have to dismantle the whole case and then it would be next to the starter pull. Really, the main reason I chose the removable door is that I can cheaply replace that part if it breaks, if I screw it up, or if I want to remove everything and sell or return the unit. I know it will be a bit of a pain when I do oil changes.

Let me say that BEFORE I mounted the regulator I installed and tightened the pipe connections I would need on it. I figured it would put less strain on the mounting connection points (only two and mounted to plastic) and I think it was a good idea.

 

I didn’t like the mounting hardware that comes with the conversion kit. The bolts fit loosely in the mounting holes on the regulator and were simply not has ‘beefy’ as I like. So I bought 5/16 bolts, along with nuts, washers, fender washers, and lock washers. The standouts that came with the kit were too small for these bolts and nothing was readily available, so I simply used several nuts and washers to stand off the regulator to the proper distance. I used fender washers on each side of the case and plan to add a rubber fender washer between the metal washer and the case at some point (probably un-needed).

 Inside

 
  
I attached all the hoses to a #5 propane tank and regulator, cleared the hose of air, clipped it into the quick connect on the demand regulator and started pulling. It did take me a while to get it started, but that may have been a function of clearing air out of the hoses, not having the load-block adjustment right, or giving either too much or too little propane with the primer. I did, for a while, think something was wrong or not working.

I did eventually find that about three seconds of priming and 3-4 pulls of the starter will get things going. I will say, on gasoline to would start on one pull. Not a big deal.

 

But it runs well and – as near as I can tell – runs about as quietly as the Yamaha or Honda (this was important to me). The attached video was without the Smart Throttle feature engaged and it runs more quietly with it on, but it is also running without a load. I’m very happy with the results. We’ll see how it lasts over time.
 
 

I am planning one more modification. The demand generator sticks out a long way from the side of the generator. I seems like it’s going to be a bit of a pain for storage and transport. So, if I can find some sort of quick connect that will run from where the hose connects to the load block outlet, I’ll reverse the direction of the mounting bolt hardware, so that I can remove it by loosening two nuts. That way I can quickly and easily remove the demand regulator for transport. It least, that’s the theory.

Thanks for reading. I hope this helps someone thinking about the same project.