- Joined
- Nov 6, 2008
- Messages
- 502
so what does identify this as a combat i was just saying what a combat spec should be , its obviously been modified with single carb and 850 style breather but as we know by the serial no they cant be 850 cases
Jim what do you reckon from the pic I posted a few posts back?
JimC said:Jim what do you reckon from the pic I posted a few posts back?
Combat
chris plant said:so what does identify this as a combat
RedEvo said:I'll hunt for the 'C' tomorrow
L.A.B. said:RedEvo said:I'll hunt for the 'C' tomorrow
If there's no 'C', see if there's an 'RH' number stamped near the right hand rocker cover?
RedEvo said:Whipped the tank and head steady off and found the 'C'. So it's a Combat. Not sure if that's good or bad
JimC said:I've run my Combat both with and without the cylinder base decompression spacer. No problems either way. Used 93 octane fuel and Boyer MK III ignition.
L.A.B. said:And how is Aboyne these days? As I haven't been there since the early '70s.
RedEvo said:I've discovered it's got MkIII Micro Digital ignition
RedEvo said:What fuel should I use with the bike and should I be using some sort of additive?
RedEvo said:it's perfect Commando country (apart from the deer :shock: ).
L.A.B. said:RedEvo said:I've discovered it's got MkIII Micro Digital ignition
I think you have either got a Boyer "Micro Mk3" analogue (Black box) ignition, or a Boyer "Micro Digital" ignition (Red box) as I've never heard of a Boyer "MkIII Micro Digital"?
http://www.boyerbransden.com/products.html
RedEvo said:I'm wondering about this because the last time I rode the bike I was very aware of pinking.
illf8ed said:Hi Dave,
Your photo is definitely a combat engine - narrow space between the head lowest fin and cylinder top fin. It already has the breather modification that I did. That fixture on the back of the timing cover is the "combat breather", just moved from low on the left crankcase. Scratch my comment about not doing that mod...you already have it.
Combat heads have a "C" stamped in the center of the head under the head steady if at all (some had no stamp). Also nearly all 750 Commandos coming to the US with 201xxx were combats as we Americans had a need for speed. You Brits didn't get the good stuff right away as it was shipped to the where the money was.
David
L.A.B. said:RedEvo said:I'm wondering about this because the last time I rode the bike I was very aware of pinking.
That's probably a lot to do with running high (10:1?) compression with low octane fuel?
The Micro Digital advance could suit it better, but it's difficult to say. There are also more modern ignition systems available these days, such the digital Tri-Spark 'Classic Twin' and Pazon Sure Fire (analogue) and Smart Fire) digital systems, plus the new Boyer MkIV which I know nothing about so far.
illf8ed said:That fixture on the back of the timing cover is the "combat breather", just moved from low on the left crankcase.