# Lack of Power in Accucraft 2-6-0



## mocrownsteam (Jan 7, 2008)

My friend has an Accucraft Nevada County Narrow Gauge 2-6-0 which runs just fine when it's not pulling any cars. The minute he puts 3 Accucraft cars behind it the loco struggles to pull them except when the boiler pressure is a full 60 lbs. When it's below that it has a real hard time.

I've checked the steam line and the reversing mechanism and I'm stumped. Any ideas?

Mike McCormack
Hudson, Massachusetts


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## highpressure (Jan 2, 2008)

Hi Mike;
Look for a partially plugged superheater line. Remove the super heater line & shove a wire up it from the front straight part.. You will find blockage at the shiny black outside area where the poker makes it the hottest. Use a brass or steel rod that fits the tubes inner ID loosely and grind a 70 degree angle on the part that goes in first. Put it in a battery drill & ream the inside of the super heater as far as you can go, a bit of WD-40 helps. We found this on one this week end at Ernie's steamup. Good luck.


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## sunny1 (Oct 13, 2008)

i also had problems with the mogul it likes to run at 60 lbs and should pull three jackson sharp cars on flat track .clogged steam lines can be a problem as well as the steam chest lines could have a blockage .you might contact cliff at accucraft


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## zubi (May 14, 2009)

The Mogul should run!! http://www.youtube.com/user/zubisan#p/u/33/HABBK2UgW3I Best, Zubi


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## JEFF RUNGE (Jan 2, 2008)

Well Zubi, I watched the mogul run "lite" for six minutes, Which Mike said his did just fine.. he want's his to pull a few cars i think?? hehe


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## zubi (May 14, 2009)

OK OK, Jeff, sorry for wasting your 6min. Well, Mike, perhaps there is something wrong with the cars?? Best, Zubi


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## JEFF RUNGE (Jan 2, 2008)

Zubi, I just kept watching, expecting to see a clip with some cars in tow... watching a live steamer running is NEVER a waste of time...


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## rbednarik (Jan 2, 2008)

In addition to checking the steam pipes for blockages, replacing the O rings on the pistons would be a good idea as well. I have found that the factory O rings tend to wear flat, and have seen some factory fresh models that have poor quality O-rings fitted. Some Silicone or Buna-N O rings should help solve most of the blowby. 

Sizing should be 10mm id x 2mm thickness


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## Jim Overland (Jan 3, 2008)

My mogul runs good but not great. Need to have the pressure up to 50 psi, so I loose some run time 
Probably the overhaul sound good 

jim


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## ETSRRCo (Aug 19, 2008)

My mogul performs great. I've pulled seven AMS cars no problem with the loco holding 40psi. ATM it isnt going anywhere cause its in pieces for repainting. One thing I noticed is that even though the cylinders are quite large on the mogul the bore is rather small. Its not much over a half inch but there is still a lot of meat on the cylinders. You could inlarge the bore of the cylinders by almost an 1/8th of an inch. This would give the locomotive more power however at the same time would slow the it down a bit. This is probably the route I'm going to go along with some valve work. Once I have it all done and back together I'll let you know how it works out.


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## sunny1 (Oct 13, 2008)

you might want to re think having your engine bored thje steam holes that feed steam in to the ciylinders come in at a angle 
so by boring it you will change the timing and alow the steam in to soon


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## Kovacjr (Jan 2, 2008)

How would the cylinder passages affect the timing as the valve ports and passages are untouched.


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## JEFF RUNGE (Jan 2, 2008)

Jason, I was about to ask the same thing, but then re-read, he is talking about opening up the steam passage which may advance the timing if the port is enlarged toward the inside of the valve chest.


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## sunny1 (Oct 13, 2008)

from what i understand the steam ports that enter the cylinders are drilled at a angle,not 90 degrees the larger the cylinder 
is bored the hole would move to a new position ether closer to front or back depending on what angle its drilled


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## livesteam5629 (Jan 2, 2008)

Call Dave Hotman. He is the expert on Accucratt engines and the official repairman. You wont regret it. 
N


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## Kovacjr (Jan 2, 2008)

Correct Jeff but reguardless where the steam enters the cylinders will never affect the timing. If the ports are the the ends or even .100 from the end of the cylinder on a angle no matter how big the bore (Dave Hottman did 7/8" on one) the timing wont change. You may need to notch the bore where the port is if the piston comes past it. 
Havent had my Mogul apart yet but going by how Accucraft makes the ports on the piston valves there is a recess in the cylinder top that is the steam channel then a drilled hole at the end into the bore.


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## JEFF RUNGE (Jan 2, 2008)

Jason, I was referring to the opening in the steam chest, not in the cylinder. That said, I was NOT thinking about this being piston valves, but rather as if was a D valve. which I guess it is not. too bad.


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## Kovacjr (Jan 2, 2008)

The valve OD and valve bore remaim untouched enlarging the cylinder bore. Even if it was a D valve the bore dia still would not affect timing.


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## FH&PB (Jan 2, 2008)

When I got mine, it would run light pretty well for about ten minutes with the burner running all out, then it was out of steam. Turned out the valve pistons were poorly matched to the valve chest and they were leaking everything the boiler could throw at them. 

I called Cliff at Accucraft, they paid to have it sent to Dave Hottman, and it came back a very strong and smooth runner. Dave put O-rings on the valve pistons, which sealed them up niceliy. This probably involved turning a seat in the pistons, so it's something best done under warranty, if the engine if fairly new. 

I'm a little dubious about how long these O-rings will last, since the valves and chest weren't designed with them in mind. But if they get torn up after 100 hours of running, it may be my heirs that have to deal with it, so I'm very happy. 

Once this little glitch was fixed, it's a great engine!


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## Kovacjr (Jan 2, 2008)

Vance, The Valve O rings should last as ling as the piston rings as the valve is grooved for the Oring at the proper tolerance to seal against the valve bore whith I think is 5mm. EVen is the bore is different you can compensate for it on the groove depth to still maintain the proper pressure on the O-Ring. Usually about 5% squeeze.


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## mocrownsteam (Jan 7, 2008)

Thanks for all the good info and ideas. Also thanks for the so-so ideas (VBG!!!). That is what is so great about this forum. Everyone chimes in to help. Looks like I have some work to do on this (forecasted stormy) Saturday while SWMBO visits here sister in Maryland. It's just me and the dog..
Mike McCormack
Hudson, Massachusetts


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## Taperpin (Jan 6, 2008)

mike , 
To diagnose wether it is vavle leakage [at the reversing valve in the centre of the frames] 
[1] put air into the boiler. 
[2] select forward or reverse 
[3] open throttle small amount, 
[4] Restrain the Drivers with fingers and let them just move if the reversing valve is leaking.you will hear a constant exhuast "Hiss" up the Stack.now it may be that a fine adjustment of the reversing valve position will stop this..in whcih case yuore home,,but if leakage is always there,the only successful cure is fitting O rings to the valve , this is acomplete cure and the rings so far have not failed on several locos we have done. 

Gordon.


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## Geoffc (Dec 27, 2007)

I have a Mogul that was running pretty poor in the begining- I followed Dave Hottman's article on "air tuning" (I believe you can find it in the archives) and now it runs like a swiss watch. I would'nt rule out a tuning issue. These should be fairly strong pullers when they are running well.


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