I'm looking at purchasing the Altima 131 fat bastard engine and putting it in my '05 big dog chopper curious if this will fit ?

[05BDMchopper]

Okay smart guys
I'm looking for real answers here
I'm looking at a Altima 131 fat bastard. Does anyone here have experience installing this into a '05 big dog chopper frame and mating it to a synchronized left side belt drive and also on what carburetor to put on it

 

[DynoDave]

Do you mean Ultima?
This is an Altima;

 

[Mickmorris]

Well if you are buying the Ultima Engine, I believe Ultima will cut you a deal on the R1 carb for that engine. Welcome from Florida btw! Hope you find the help you need here!

 

[05BDMchopper]

Do you mean Ultima?
This is an Altima;
View attachment 80944

Nice catch I guess I should have re-read my post , got to love modern technology and voice recording text through your phone

 

[knothead]

It should fit....the ultima 131 is only going to be 1/4 taller motor...117 thats on your bike is a 4 3/8" stroke and the ultima 131 is 4 5/8" stroke.... you may have to fab a top motor mount if your mount doesnt have a slot machined in it so you can adjust the height to mount the coil cover....either way isnt a problem to make....if your motor is still on the frame take a look and see if you can stand another 1/4 taller motor....i believe you will be good

To the carb question all the 131 engines i have looked at come with carb.....ultima r1 carb

 

[05BDMchopper]

It should fit....the ultima 131 is only going to be 1/4 taller motor...117 thats on your bike is a 4 3/8" stroke and the ultima 131 is 4 5/8" stroke.... you may have to fab a top motor mount if your mount doesnt have a slot machined in it so you can adjust the height to mount the coil cover....either way isnt a problem to make....if your motor is still on the frame take a look and see if you can stand another 1/4 taller motor....i believe you will be good

To the carb question all the 131 engines i have looked at come with carb.....ultima r1 carb

Thank you , I see now that it will come with a carb , are the out put shafts the same ? I'm assuming they are

 

[05BDMchopper]

Thank you , I see now that it will come with a carb , are the out put shafts the same ? I'm assuming they are

Sorry , additional ? What exhaust can I run ? I like full duel or does 2 into 1 have advantages

 

[Mickmorris]

I have always liked duals. Just a personal preference. I sure like the ones knothead put on Frankenstein. I just bought some new short shooter drag pipes but thinking of sending them back. They weren’t exactly what I was looking for. Who knows may just put them on to see if they grow on me. I can’t think of any advantage to 2 into 1.

 

[Drdave427]

I have always liked duals. Just a personal preference. I sure like the ones knothead put on Frankenstein. I just bought some new short shooter drag pipes but thinking of sending them back. They weren’t exactly what I was looking for. Who knows may just put them on to see if they grow on me. I can’t think of any advantage to 2 into 1. View attachment 80948

Other than having 1 FAT PIPE — not sure of any performance difference though

 

[05BDMchopper]

Yeah I like duels , that way I can put my finger over the end and make sure the compression is equal on both cylinders. I'm assuming the output shafts are the same to hook to my primary belt drive ?

 

[Mickmorris]

Yeah I like duels , that way I can put my finger over the end and make sure the compression is equal on both cylinders. I'm assuming the output shafts are the same to hook to my primary belt drive ?

Yes I do believe that to be correct. If you are purchasing directly from Ultima they should be able to confirm that.

 

[05BDMchopper]

Thank you , I will check as I order
Much appreciated info

 

[knothead]

Thank you , I see now that it will come with a carb , are the out put shafts the same ? I'm assuming they are

If your talking about the crank shaft then yes your compensator will go on

 

[knothead]

To what MickMorris was talking about on exhaust i ordered the laf ambush exhaust from accesorieshd.com....they are 339.13 tax and shipped....they sell them on ebay also....

 

[05BDMchopper]

I'll look at these , thank you

 

[FrankBDPS]

Call John Sachs. He is into those motors.

 

[1 B.M.F.]

Go with a mukini smooth bore carb. easy adjust and you can make that engine purr, or lope. Purrrrrrrrr or lope lope lope lope.

 

[john sachs]

Go with a mukini smooth bore carb. easy adjust and you can make that engine purr, or lope. Purrrrrrrrr or lope lope lope lope.

48 mm. Mikuni.
John

 

[Mikeinjersey]

Yeah I like duels , that way I can put my finger over the end and make sure the compression is equal on both cylinders. I'm assuming the output shafts are the same to hook to my primary belt drive ?

Welcome from NJ
IF that's how you check compression " YOU ARE THE MAN"

 

[05BDMchopper]

48 mm. Mikuni.
John

Thank you , I'm going with the R1 carb it comes with for now. If I have problems I'll go 48 mm Mikuni , I'm looking forward to this 131 swap project

Welcome from NJ
IF that's how you check compression " YOU ARE THE MAN"

I actually lost part of a ring on my 117 s&s and I could tell it was the back cylinder by less snap on that exhaust pipe and you can smell your fingers and tell if they're both running properly with the mixture