Jump to content

Red Diamond not quite right

Recommended Posts

At the museum we have a Red Diamond in one of our pieces of equipment. Its not the original engine but a re-power performed

decades ago when the chassis got separated from its original engine.

A year ago we performed a tune-up - new plugs, cap, points, condenser, wires, coil etc. and it was purring like a kitten.

This winter it started miss behaving - dropping a cylinder or two. When we pulled the plugs they are fouled. We ran a compression

test and all is spot on. We again gave it a  tune-up. It ran great for a less than an hour and fouled up again.

Last time we ran it it was popping and missing. I am thinking too lean? Its also always the same plugs fouling 4, 5 & 6

Its running a Holley 2140-G carb. It seems like a carb issue ? Am I barking up the wrong tree??





Here is the beast its in. The original engine was a massive six cylinder Wisconsin D4 (1,013 cid) If you know where we can find one of those ...............?




When they re-powered it back in the 1970's they installed a  auxiliary transmission in front of the original unit which is a massive 3 speed made by Cotta.

We run the auxiliary locked in 2nd. Note the funky exhaust pipe. It was installed that way so the original exhaust cut-out in the hood could be used. That Red Diamond

is a little lost in there but it moves it along just fine.



And the original engine.







  • Like 2
Link to post
Share on other sites
  • 4 weeks later...

 I viewed one of those in person at Churchill Dam, on the Allagash River in Maine, maybe 45 years ago.

 I believe that one was fitted with skis, rather than wheels in front.

 The engine was the original, a huge beast.

 The tractor may still be there, Google earth shows a pavillion structure at the site, maybe it is under cover.

Link to post
Share on other sites
  • 1 month later...

Gasoline with ethanol will ruin any rubber gaskets in the carb. The exhaust valve seat are designed for lead in the gasoline. The exhaust seats will burn if ran for an extended length of time. When lead was taken out of gasoline, the exhaust seats had stellte seats installed in subsequent engines.


  • Like 1
Link to post
Share on other sites
  • 4 weeks later...
  • 3 weeks later...

Hi Guys its been awhile and I apologize for that. I appreciate all your responses. This week I will be heading back to the museum.

We are going to do a complete diagnostics of the ignition system - could a be a bad condenser etc. We will check.

Also looking at the intake to see if there could be a leak. (hate the idea of taking that apart!)

We have been running non-ethenol fuel for a while. Early in the winter and in early spring we can have wide temp fluctuations with it being above freezing then

dropping to below freezing in a few hours or visa versa which isn't good for a large fuel tank with not much fuel in it.

Supermechanic yes there were a number of these beasts at Churchill. The one you probably saw is now in the State Museum. I have an original engine

in my shop that came out of Churchill:

These were big six cylinder Wisconsin T-heads (5-3/4" x 7") 104 hp at 1200 rpm but massive amounts of torque. The crankcase is a 500 lb manganese bronze casting.


Link to post
Share on other sites
  • 3 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...