All posts by dstech

Fourtrax 300

I just got my first atv for free from a friend. It hasn’t ran for a year. I had it running on half choke for a few days so decided to take it down my land. Got to the bottom and magically any power would kill it. Wonderful. Managed to get it back up the hill with my truck. So I bought a new carb and a starter (have to smack it to get it to turn over 75% of the time)

Anyway, I’m wanting some more low end and mid range power. I did ride this atv before it sat for a year and was running right and thought it needed some more grunt.

I’ve searched and decided the FO-4 muffler would be a good add on for power everywhere on the power band. I’m wondering, what cams are available? I saw the 88 but it is only top end power. I’m not looking to go fast on trails, and I don’t really want to take it mudding that much. If I do get in mud it’s no more than 2-3 inches deep (just the way my land is).

An additional question would be, if I just wen’t with the muffler and a k&n filter, what jet size would i need to run? No one has seemed to put this information out there. I saw #168 but wasn’t sure of all his mods. I’m new to carbs and watched a 30 minute video about how to take this carb apart and clean it, put it back together and tune it while idling. That’s the extent of my knowledge.

Thanks :yeahbaby01:

Fourtrax 300

I just got my first atv for free from a friend. It hasn’t ran for a year. I had it running on half choke for a few days so decided to take it down my land. Got to the bottom and magically any power would kill it. Wonderful. Managed to get it back up the hill with my truck. So I bought a new carb and a starter (have to smack it to get it to turn over 75% of the time)

Anyway, I’m wanting some more low end and mid range power. I did ride this atv before it sat for a year and was running right and thought it needed some more grunt.

I’ve searched and decided the FO-4 muffler would be a good add on for power everywhere on the power band. I’m wondering, what cams are available? I saw the 88 but it is only top end power. I’m not looking to go fast on trails, and I don’t really want to take it mudding that much. If I do get in mud it’s no more than 2-3 inches deep (just the way my land is).

An additional question would be, if I just wen’t with the muffler and a k&n filter, what jet size would i need to run? No one has seemed to put this information out there. I saw #168 but wasn’t sure of all his mods. I’m new to carbs and watched a 30 minute video about how to take this carb apart and clean it, put it back together and tune it while idling. That’s the extent of my knowledge.

Thanks :yeahbaby01:

Picked up a defender

I bought the base model (no DPS) with The convenience package. Its $500 more and gives you the tool box on the dash and the unlockable rear diff so i can turn on turf mode. $12,700 OTD.

Attachment 44505

I added a few goodies.
Winch, very easy to install, all plug and play and just a few bolts.

Roof
Windshield
Rear window
3 way mode switch
And i swapped out stock 25" stock tires.
I put on ITP Mud Lite XTR.

Attachment 44513

So the first thing i did was put it to work.
Im working on a future riding arena for my wife. Attachment 44481

Attachment 44489
Attachment 44497

I will have to say, this thing pulls like a tractor.

TRX500 bad fuel

I worked on a friends 2007 TRX500FM7 yesterday , the bike is super clean and only has 240 miles , was garage kept , BUT , it sat for 3 years with fuel in it , what a mess , the float valve was so jammed in the seat that I thought I wasn’t going to get it out , it took needle nose vise grips and a lot of pulling , the petcock was so clogged up no fuel was going thru it and you can’t turn the knob , I found a screen inside the fuel hose right at the carb (there is a pic of it ) , it doesn’t show up in the parts print , take a look at the fuel that came out the tank in a clean 5 gallon bucket ——–

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2002 500HO Carb Jetting sizes

Hello, new to the forum. Just picked up this ATV and looking to have it run a little stronger. I’ve been reading several threads here on this issue but I haven’t found exactly what I’m looking for?
I’m installing a K&N air filter and want to bump up the jets to maximize performance. I noticed that without an air filter and cover, it bogs under full throttle. Can someone recommend the max jet sizes to accommodate the (hopeful) increase in air with the K&N? I wasn’t planning on changing the exhaust (I’ve been reading that some here say performance is negligible?), however, if someone has a noticeable performance increase package; air, jets, exhaust, – I’d love to get that info.
Thanks in advance!

BL