My new M17MCHF Decontaminating Apparatus

[robertsears1]

Monday, I drove up to Norfolk, VA to pickup a M17MCHF Decontaminating Apparatus from GL, $438 all in. Two were auctioned off, mine has 1.6 hrs and the other was zero hours. Both came with the accessory kit box and one output hose. Mine had the 30' intake hose inside the box. Neither had the portable 1580 or 3000 gal water tank or the two jerry fuel cans pictured in the listing that the TMs showed and the man at GL seemed offended that I even asked about it. I also picked up a brand new H81 heater at Portsmouth but that will be another story.

The M17MCHF is a small Hotsy type unit that is self contained so it heats up the water and should get the water pressure up around 100 psi. The water heater part runs off of gas, diesel, kerosene, jet fuel, or any mixture of fuels. That makes sense. I have two MX-2 steam cleaner units but they have many interlocks that can be tricky to get working together plus you need electrical power. They burn diesel or jet fuel to heat the water and can be either supplied water with a hose or suck it out of a pond/tank.

The thing that is confusing me about my M17 is the fuel for the engine. All of the TMs except one show a different but similar engine that is 197 cc made by a company that used to be in SC (2si or Two Stroke International) and it runs on gasoline with oil premixed since these are all two stroke engines. One TM in passing showed a picture of an engine very similar to mine that is 215 cc but it has the carb on the side. Mine has the carb on top and a small tank for the mix oil that seems to inject the oil at the carb. None of the TMs talk about this part. I did find a old GL listing from 2014 for a M17MCHF modification kit that shows my exact engine and it had a separate mix oil tank. This unit is made to use a 5 gal jerry can for the engine fuel and another for the burner fuel. The fuel pickups are modified fuel caps with a yellow tag that says "Engine Fuel JP5/JP8 only" so that is basically diesel or kerosene, right? This engine has a sparkplug so it is not a diesel in the traditional sense. I know old tractors would start on gasoline and after warm switch to kerosene (distillate). I am concerned about killing a new engine. My first thought is to try to get it running on mix that we use for the chainsaws (40:1) so worse case it would have too much oil to start with. I found on here a thread from around 2014 talking about one of these (can't find it now) and he seemed to say he ran it (the engine) on diesel/kerosene mix until he blew up the heater coil (less that 10 minutes running time) since the volume of water was not enough from a garden hose. Sorry, no pics yet, still trying to figure out how to shrink them down since I got a new IPad and they are way too huge.

Robert

 

[FloridaAKM]

I have two of those units, in the same shape yours are. They are still stored as picked up, unused till the day I have time to pull them out of storage & use them. As you have read, do not starve the unit on water when you get it running, it needs lots of water to run properly instead of exploding the heater core! Good luck with yours & you need a TM on it!

 

[robertsears1]

Thanks, it came with TM 3-4230-228-10 which covers everything except the engine installed. I just got off the phone with the man that bought Cuyuna/2si engines (zdenterprises.net) and he has some parts. He said my engine was made to run on diesel or jet fuel and oil gets injected from the oil tank for the mix.

Robert

 

[robertsears1]

I ran it .6 hr today using diesel for the engine and burner. Compared to the MX-2 washer, this is much simpler to operate. I used a 30 gal trashcan as a header tank and ran the garden hose to it. The hose supply kept up fine with the demand. The engine started after about four pulls and it puts out a dense white smoke for approx 30". The smoke appeared on every restart. The burner cycled fine to keep the water around 100 C. That feature worked much better than my MX-2 since it always tries at least once to get up around 500 C if you are not paying attention! The output hose is heavy and the sprayer would switch between a spray to a stream sometimes. I used it on my backhoe which is very greasy in some spots. It would start to melt the grease but solvent is needed to get it clean. I did not try the injector but I do not see why it would not work, the book said it puts out a ratio of 80/20 or 4 to 1. Restarts are not totally easy but my shutdown procedures need work. When the burner cycles, it puts out white smoke for around 15 seconds. Better placement regarding the burner exhaust is needed since my eyes started to water. Overall, this unit is pretty simple to operate and using one of those 200 gal square tanks on a trailer would make this a useful unit. You could wash houses with it if you got a better sprayer wand and smaller hose since it only puts out around 100 psi of spray. I am still trying to figure out how to shrink down pictures to fit.

Robert

 

[Guyfang]

Put a picture of the engine in the thread. I may have a manual for the engine. Or tell me the model number/NSN.

 

[robertsears1]

Sorry for the delay Guyfang, I have been on the run lately and I could not get the picture issue figured out. The unit has run fine except the last time when it was cool and the burner did not want to light at first. I kept playing with it and it finally lit but there was excess fuel in the chamber and it got hot real fast. The temp went up toward 200 C where it normally stays around 100 C and the pressure relief valve let off some. I backed off a couple of minutes to see if it was going to blow until it cooled down but is working fine now.

 

[Guyfang]

I will take a look at my manual depot. I tossed lots when I stopped working on army equipment. no promises.