My Budget motor #15

foreverfaster

foreverfaster

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What is a true budget motor anyway?? My$$ are not the same as yours.. so i guess i'll answer my own question as... build what i CHOOSE to afford..

Just for fun, i'm going to track my Budget build here on this page for all to see... happy to hear suggestions along the way as well.

GOAL is to build a model 15 that looks like an animal.. (SA class)

So far parts collected and money spent.

$100. Model 15 complete motor. w/ RT1 head
$100 Briggs LO206 complete motor ( no chain guard, no clutch)





motor is shot, you can hear as you roll it over that either the rod cap end is broke or a bolt has come loose. have not popped the seals yet..
 
Building a 15 really isn't for the budget minded. Lots of mods needed to do it right. Your RT-1 head is not a simple bolt on because of differences in the oiling system. Of course we do not know what your budget will allow or what kind of performance you desire.
 
Chipg56 said:
Building a 15 really isn't for the budget minded. Lots of mods needed to do it right. Your RT-1 head is not a simple bolt on because of differences in the oiling system. Of course we do not know what your budget will allow or what kind of performance you desire.
Click to expand...

it came right off the equipment with the RT1 head already on it.. going to give it the budget effort :)
 
Yz450f complete....$700 + $10.00 in metal and time for motor mount, and $100 for piston, rings and timing chain... stock 45-50hp
Yz250f complete...$500 + $10.00 in metal and time for motor mount, and $100 for piston, rings and timing chain... stock 30-35hp
Yz125 complete... $300 + $10.00 in metal and time for motor mount, and $100 for piston, rings and reeds... stock 30-35hp...

all left with stock tranny...
gears are #50 steel... turned down $10 a piece 22-26T
 
Here is my suggestion for a budget model 15 build.
Use the stock piston, which is plated for use with the aluminum bore.
Use a billet rod for an animal. The wrist pin hole will need bored or reamed to fit model 15 piston.
Use stock crank, either from animal or model 15.
Either 308 or mod 1 dyno cam, or even wf cam.
World formula head, or stock model 15 head, mild port job, stock size valves for true budget build.
Yes, the oiling slot is really close with the 3 inch bore.
JB weld could help, best option would be to weld shut, but defeats budget options.
Or you could gamble with being able to get by as is.
Compression will be lower with the dish piston, so may be possible.

Valve springs and retainers compatible with cam.
Stock rockers, better pushrods.
Wf carb may be a little small, but should have good torque.
I'm sure there are other budget carbs, personal preference is a tillotson.
Animal flywheel and mag. Pvl if budget allows, but not required.
Try to turn 7500 to 8000.
Should make better power than wf even with lower compression.
 
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