89 Lt250r

[Yamaha1]

Im currently getting my 89 lt250r port and polished , head milled .30, and bore over. Im also adding a 38mm mikuni carb and i am running fmf pipes.
How much of a power increase should i be expecting from milled head , p&p, bore, and bigger carb?
Also how should i go about jetting this?

 

[jus_me]

As far as the jetting the only thing I can say is to plug chop and see where you stand. Also you may want to try a lt250r forum if there is one. Then list your set up and if someone has the same or similar they may be able to give you a good starting point.

With the porting, if it is done correctly and depending how aggressive the porting you will certainly feel some power increase. As far as having the head milled is this to correct the squish? If you are shaving the head just to shave it you can run into some problems. You may also need to run a higher octane fuel (higher compression).. For the .30 overbore there is no noticeable difference in power gains.

The ltr's have some nice bottom end, a nicely modded lt250r will keep up with some shee's...

 

[MercMenace]

The ltr's have some nice bottom end, a nicely modded lt250r will keep up with some shee's...

Stock with a fat guy riding it. LOL!

 

[Yamaha1]

As far as the jetting the only thing I can say is to plug chop and see where you stand. Also you may want to try a lt250r forum if there is one. Then list your set up and if someone has the same or similar they may be able to give you a good starting point.

With the porting, if it is done correctly and depending how aggressive the porting you will certainly feel some power increase. As far as having the head milled is this to correct the squish? If you are shaving the head just to shave it you can run into some problems. You may also need to run a higher octane fuel (higher compression).. For the .30 overbore there is no noticeable difference in power gains.

The ltr's have some nice bottom end, a nicely modded lt250r will keep up with some shee's...

How will I not gain anything off the milled head? High compression means more horsepower correct? Also ive beat banshees with just an fmf pipe and air box removal.

 

[Blaaster]

There was no mention of no gains with a milled head as far as I can see.

You may gain some power from the increased compression.

What was meant was, if it is just milled and the squish not set you may run into detonation problems.

The better way is to have the head rechambered and the squish set.

 

[2strokerdie]

Check out suzukiquadracerhq, there's all kinds of good info on the quadracer's there. Those guys have a wealth of knowledge about the Zuki 'so just like the guys do the blaster's here. I have an lt myself and absolutely love the power that thing makes. They supposedly make right around 30hp stock so I'd say a good port and polish with the squish set and decent pipe that you 'd b around 40-45 maybe more.

 

[Yamaha1]

Check out suzukiquadracerhq, there's all kinds of good info on the quadracer's there. Those guys have a wealth of knowledge about the Zuki 'so just like the guys do the blaster's here. I have an lt myself and absolutely love the power that thing makes. They supposedly make right around 30hp stock so I'd say a good port and polish with the squish set and decent pipe that you 'd b around 40-45 maybe more.

I will check it out. Thanks man and yes they do have great power

 

[jus_me]

Yes that is what I meant when I was referring to having it shaved... Heck,,,,, just setting to squish correctly can gain you some untapped HP .. Be sure to run the proper fuel if/when you change the head and or comp.