racing engine setup tips for 4 stroke motorcycle

[galbert]

helloo.. im just askin some idea on how to aquire additional power to honda xrm 125 for drag race... actualy we were on a race and have our motorcycle updgraded, but we still need more power or any idea to aquire 12 seconds for 400m track?

[totalmotorcycle]

Can you tell us what you have done/upgraded/updated already on the Honda XRM125?

Mike

[ceemes]

Can you tell us what you have done/upgraded/updated already on the Honda XRM125?

Mike

Yeah, otherwise the only suggestion I would make is to strap a couple of JETO bottles to the rear of the bike.....instant acceleration.

[galbert]

Can you tell us what you have done/upgraded/updated already on the Honda XRM125?

Mike

Yeah, otherwise the only suggestion I would make is to strap a couple of JETO bottles to the rear of the bike.....instant acceleration.

Can you tell us what you have done/upgraded/updated already on the Honda XRM125?

Mike

Can you tell us what you have done/upgraded/updated already on the Honda XRM125?

Mike

hello,! yeah its funny... actualy, we have complete racing gears, racing cams, stroker, advanced timing standard flywheel, top cylinder head for higher compression....standard carbs with big main jet, and little bit bigger airflow, porting vavles fit to the carb manifold, battery drive racing cdi, etc... but its still hard to get 13s run for 400 m....??

[HYPERR]

any idea to aquire 12 seconds for 400m track?

Bored and stroked 140cc ringer.

EDIT: Wait did you say 400m??? The only way that bike is going to do 12 seconds in the 1/4 mile is if it fell off a cliff.

[galbert]

yes, it is very possible, 400m in just 12s. because we have already achieve 13s in 400m...we're trying to make it 12s. I think you are not a racer my friend, or any motorcyclist, this topic is not suitable for you sorry my friend...

[HYPERR]

yes, it is very possible, 400m in just 12s. because we have already achieve 13s in 400m...we're trying to make it 12s. I think you are not a racer my friend, or any motorcyclist, this topic is not suitable for you sorry my friend...

The best guys around here are running low 13s with terminal speed of around 100 mph. I'm not positive but the lowest I've ever heard around in the Northeast US is just dipping under 13. That's very rare for a buck and a quarter(125). Even the 250s mostly run in the low 13s.

When you talk about 12 seconds, you are talking about a whole different world. 1 second is an eternity in the drag racing world. Do you realize what kind of terminal speed you need to turn to run a 12 second ET?

You are also talking about a 4 stroke engine that was originally meant to power a scooter type transportation. Air cooled single cam 2 valve to boot. We are talking about an engine that makes 10 HP stock tops. If anything, I am amazed that you can even get them to run a 13 second zero yon(quarter mile) with that engine.

As for the insults, I am just going to dismiss it as a product of the language barrier.

[Wrider]

Here's a list of what I can think of.
Higher compression piston with race gas.
Lighter bike, especially drivetrain components like the chain, sprocket, wheel, tire.
Lighter rider, on a 125 the rider weight makes a HUGE difference.
Turbo
Nitrous
Lighter cams/valves/springs for a higher RPM limit.
Big-bore

Oh and the most important part of all, respecting established members of forums with racing experience where you're asking advice from.
He is right, a 125 running a 12s 1/4 is insane, and quite honestly Hyperr, even gravity only gives you so much acceleration... haha

[HYPERR]

Big-bore

That's what I said originally but that would make it a ringer.

But then again, how are they gonna know.

[Wrider]

Not sure what you mean by a ringer?