[Dave04da]

Just picked up this '99 400ex for 1,200 bucks to ride with my son on his trx90. It seems to be well taken care of for a '99. I adj. the valves, chain and carb. Changed the spark plug, oil and set the rear shock at its max stiffness. This is my first sport bike, and I must say its a lot of fun and pretty quick for what it is. I included a few pics. of mine and my sons.

 

[LedFTed]

Welcome, looks nice..
i noticed something in the garage, black, interesting...

 

[SlammedRanger]

Very nice quad. And nice trans am. We just finished building my brothers ls1. Cam, long tubes. And first run down the track was a 12.6. Got more in it just needs bigger injectors. Duty cycle is maxed out on the stock ones. Welcome to the forums!

 

[Dave04da]

Thanks guys. Yea, thats a '99 as well. It's a Firehawk Trans Am, I did a cam, pp the heads, ls6 intake, LT headers. 3.91 gears, ect. She runs pretty good. My best 1/4 mile was a 12.6 as well at 115 mph. Street tires and babying out of the hole (trying to make the 10 bolt last as long as possible) I don't track it much at all. Just have fun on th street.

 

[SlammedRanger]

That thing is clean! It looks just like my brothers first one. This one he has now is his 3rd. His first one was pretty gnarly it was running 11s. Had a 150 shot. Gears. Drag radials. Stall. Long tubes. And a texas speed intake. Hes trying to get this one to a 11.9 n/a. We did gear it and stall it aswell. Forgot about that. I think with drag radials and bigger injectors we will have him 12.1 maybe 12 flat but hes determined for that 11.9 lol

 

[Dave04da]

Sounds sick! Its amazing how well the ls1 responds to mods. Its a great engine.

 

[Dave04da]

The 400ex has 22" tires on the back. I am mostly going to use it for trail riding. Do you guys think I should go with a 14t sproket? Or do you recommend something else?

 

[SlammedRanger]

Yeah he spun a rod bearing on this motor is why we rebuilt it. Had the crank polished. Did arp rod bolts since those are a weak link on these motors. Most of them werent even torqued anymore when we pulled it apart. We had the heads worked and upgraded valve springs and did a trunion upgrade on the rocker arms. It was a fun winter project. He blames stretched rod bolts. I blame the 300 foot burnout mark out front of his house lol. But on subject of your 400ex. 22inch rear tires are a bit much. Unless your trying to follow 4x4 quads through there ruts there will be no need for that type of ground clearance. All the trail quads run 20s in back and 21 or 22 in front. Anything smaller is mx racing sizes. A 14 tooth front sprocket will give you more torque and bottom end power but you will lose topend and top speed. Depends on the type of trails you ride honestly. I run a 13/38 setup on mine for mx racing and the trails i ride are tight and not high speed at all so its fine for them aswell.