rechambered head
- Thread starter 89blaster89
- Start date
I've heard when you get your flywheel lightened that the +4 timing mod allows you to take full advantage of the lightened flywheel ! Ive never heard anything about needing the +4 timing mod for a redesigned head tho.
I don't think there's a NEED to run +4. I've read mixed reviews on this mod. I will be testing this myself come spring.
The +4 timing mod will take away slightly from the longevity of your motor, as any performance part will ... There's always a trade off. The +4 timing mod is roughly equivalent to running an aftermarket exhaust ( which most of us do anyway ) in terms of strain on the motor.
Couple interesting dyno graphs here
:Workbench - Snyder Motorsports
Shows where you gain in mid range and lose a little on top.
:Workbench - Snyder Motorsports
Shows where you gain in mid range and lose a little on top.
i dont think mods take away the life of the motor, ive been on the same topend for 7 years now with a pipe and no airlid, just gotta jet it right
A re-chambered head thats properly designed will give the air/fuel mixture a much FASTER more EFFICIENT burn,making the timing advance not needed. You could try it with +4,but I believe (I have not tried it) that you will run into detonation.
I don't understand this whole + 4 timing anyways. I get what it is an what it does but i don't get how it doesn't cause detonation. Are stock blaster timings slight retarted from factory?
I wouldn't say that the engine was retarded from the factory. Its just Yamaha left lots of room for improvement. Just like all the other engine mods that can be done to this little engine.
So kinda like the whole head deal they jus didn't do everything they could. How do u advance timing safely an do u need to run race fuel if u do to prevent detonation
Basic design was for a beginer. Basically a "detuned" motor, more so than even old enduros compared to MX. Actually be glad there's room for improvement. To bad they didn't make it so they could have a 250 GYTR kit.
And if it weren't for the damn tree huggers, we could at least stuff one of these in, DT 230 :
http://www.google.com/imgres?hl=en&...w=185&start=0&ndsp=15&ved=1t:429,r:2,s:0,i:96
http://www.google.com/imgres?hl=en&...w=185&start=0&ndsp=15&ved=1t:429,r:2,s:0,i:96
You are so right Larry!
The cone shaped combustion chamber is designed to give a slow soft burn to limit power.
The cylinder seems to be designed for a 60mm stroke but isn't, the airbox lid is designed to limit power.
And of course, the timing has a lot of "safety" built into it to avoid pre-ignition.
The goal of the rechambered head is to get a faster, more efficient burn. This is the key to power.
Since the burn is faster, you don't need as much timing advance to get it started.
Something to know about 2 stroke timing is that because of the pipe effect, it is the opposite of a 4 stroke.
The pipe acts as a supercharger, wildly increasing the cylinder pressure. Like a supercharger, it needs less timing.
So the timing advance on a 2 stroke usually stays constant on a mild motor, actually retards with rpm on a hot tuned motor.
Steve
Wow a two stroke enduro bike. This is awesome.... I want one!! Is it not legal to drive these on the roads in the states or something? Surely you can find one for sale, look like a newer model...
Blaner
Your Friendly South African Ambassador
Every single time I have run the +4 mod it has cost me a piston. Bottom line its risky. It fees good but when the going gets tough and the heat gets to much it will start to ping relentlessly and finally let go.
Ignition timing is a dangerous way to make power. Go with the rechambered head. Remarkable difference. It makes the motor burn more efficiently, thus you end up with better utilization of the fuel as it is atomized better and combusts more completely. = more power, cleaner burn
Ignition timing is a dangerous way to make power. Go with the rechambered head. Remarkable difference. It makes the motor burn more efficiently, thus you end up with better utilization of the fuel as it is atomized better and combusts more completely. = more power, cleaner burn
