Honda TRX250R Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
63 Posts
Discussion Starter #1 (Edited)
Guys, my 1983 CR250R hotsaw build is coming near to completion ready for testing starting out with stock cylinder porting.
I bought a brand new 2003 CR250R FMF gold series fatty pipe for $170US & free shipping. Felt it would be a great pipe to hack up in testing to eventually build a custom hand built cone pipe after I get porting etc to tune.
My dilemma is the 2003 CR250R is a case reed versus my 1983 cylinder reed. I will have my porting around what the 2003 is at approximately 190°/130°.
But a adjustable length header and stinger may be needed for the differences in crankcase and cylinder reed assemblies. So the case reed distance should be shorter to the outlet flange then the cylinder reed cage? If that's the case I should lengthen the header for my cylinder reed cage?
 

·
Registered
Joined
·
13,182 Posts
"But a adjustable length header and stinger may be needed for the differences in crankcase and cylinder reed assemblies. So the case reed distance should be shorter to the outlet flange then the cylinder reed cage? If that's the case I should lengthen the header for my cylinder reed cage?"

I would not.... this is a slippery slope. Theory is fine, real world is a lot different. If it was my saw; I would start equal lengths, on the long side for each, and adjust on a bench Dyno under a real-world load. The only real way to answer your question correctly.

Carlos
 

·
Registered
Joined
·
63 Posts
Discussion Starter #4
Thanks for the reply Carlos,
The FMF pipe is just temporary while I test and run in the engine. I'm working on a blue print drawn up of a slip style joint for the header .
I think 2 inch adjustment would be plenty to dial it in as I go along with testing and then cylinder and head modifications later on


During run in of the piston rings and bearings the saw will always be under load making many short rpm controlled cut runs through a 16 to 20 inch diameter log.
The only way to get used to the saw, testing for efficiency and ergonomics and durability.
I'll be busy as I'm building two hotsaws side by side at the same time.
Finishing touch will be a custom hand built pipes.
Already got the YZ125 pipe welded up ready for mounting.
64546
 
1 - 4 of 4 Posts
Top