SlammedRanger

Hey now! I resemble that remark! LoL

Post a picture. I will tell you which one its from. Welcome to the forums! Sounds to me like it has a dyno jet kit. Those jets go on a totally different scale.

Some pictures my wife took. Daughters first race! Super proud dad! Only one out there on a honda!

Few videos my dad took of the fair motocross race this year. Had a rough 1st moto. Not as rough as the guy that lost half his finger. But i started 4th. Made a pass for 3rd. A buddy of mine spun out and i was in 2nd. They red flag the race just after we pass the finish line. We had no idea. We kept wheels on ground through caution flags and right when we got out of yellow my buddy punted me. Entirely on accident. He stopped and i came out with just some bruised ribs. 2nd moto i got 3rd. Alittle gun shy after the dirt sample lol.

Sounds good! We have a download for the fsm on here. Its on the drop down tab at the top corner. Service manuals.

Almost sounds like something is binding on that clutch main shaft. I would still start with the easy stuff here and check the shift drum end bolt though. Thats where my head goes first and its simple to just remove the side cover and check it out. Pictures help alot with getting these thing sorted also. So anything you can snap pictures of will help us out bud! We will get you through this deal. Just hope its not in the cases. I have split many but its just not a fun task for anyone lol.

Welcome to the forums! Sounds to me like the shift detent at the end of the shift drum came loose and is out of alignment. This would make shifting really random just like you are talking about. This can be checked by removing just a side cover. Doesnt require splitting cases. The detent looks like a star has a single pin that fits in a small hole in the shift drum housing. There are valleys that a wheel on an arm with spring tension hold in place. It has a 10mm bolt down the center that requires red locktite on it. Have seen them come loose many times.

Sounds like a few things. You will want to put a 42 pilot jet in it. Probably running a stock 38 with the mixture at 2.5. Your goal is the 1.5-2 area. And anything above 3 is telling you to up the pilot jet a few sizes. I would also suggest dropping the clip on the needle one slot. When you start having off idle bog its usually not getting enough fuel. AKA lean bog.

Sounds like a good possibility! Keep me posted if you need anything!

You said drive sprocket moves. So you must have removed the chain already? If not the 1/4 inch forward and reverse would indicate it is in gear. Unless the chain is removed and you can spin the drive sprocket freely. You will have some slop back and forth even when in gear. It wont like lock solid.

I would bet the rear axle carrier bearings are bad. Put the quad up on a jack stand and grab the rear tire and see if it has alot of up and down play.

Sounds turbo related to me. Seems like the only thing on the truck that would be spinning that fast at that low of an rpm. Those tiny economy turbo's spool at a really low rpm. Could also be why it seems to just stop abruptly sometimes. Something is in there catching and stopping it.

Heres a couple pictures. Gotta upload the videos to youtube and they will be up.

Happy fathers day to all the fathers out there! Got a proud dad moment gunna happen in about an hour! Taking my daughter to her first kids track to turn some laps on her trx90. Gunna see how she does and fingers crossed she loves it like i do! LoL im sure videos will be taken so i will post them up later!

Glad you got it sorted! Always glad to help out! I would suggest against using gasket maker on the center case gasket. If it leaks down road its a long road to fixing it from that point. Also since the 400ex is designed to have a gasket it is required for proper spacing in the transmission gears and shafts. Some quads use gasket maker from the factory and are designed to not have a gasket and in that case it would be 100% ok. But sadly not in this case. I have used hondabond on side covers in a pinch and had no problem. My .02

I would bet that is your culprit right there. That gear is probably on backwards. Like i said before. The manual does nothing to help you with gear direction. I have found the diagrams show it wrong and make it look like they go the wrong way.

Yes the washers are more like shims in this purpose. They keep the gears from hitting anything they shouldnt. But most important is to narrow down which shaft is binding up. That will be the one we need to pay the most attention to.

When you bolt it together can you still move the shaft that the sprocket goes on in and out? It should move in and out about a 1/16th inch. Not much but some. If its not moving at all its binding and that would indicate that shaft is the one in question. Honestly would be the easiest option. The other shafts are harder to get to to see if they have no in and out play. All the shafts will have a small amount of deflection. If it has none that is the problem area. Could be any shim being too thick. And we are talking very small tolerances. So you will need a caliper to measure them. The manual will have these thicknesses somewhere hidden. If we need to go down that path i will help you. But hopefully its just the main shaft. That makes life easier.

Sport quad guy clocking in! LoL. Ok so transmissions are very tough. Need to be precise. And one shim thats too thick in the wrong place makes a world of difference. Also the service manual does you no favors. Alot of the gears on the pictures look backwards. It is very hard to tell from there pictures which side the bevel goes on and which side the flat side goes on. You gotta make sure those are all bevel facing the sliding gear. So it would be gear bevel 》sliding gear(the one with big teeth on both sides) 《gear bevel. Pictures make this look confusing.

Yeah i know they sell them for a 400ex and 450r stem. But it would be a real long shot on if they are the same thread and size. Kinda doubt it being that lonestar is gunna use a standard bolt and thread. Honda ones will for sure be metric.

Bofore using loctite i would get a nylock nut. My lonestar steering stem came with one and i still put the cotter pin in for good measure. But the nylock nut should make it stay put and still be able to be removed down the road.

Yep those would do it. The only scary part of changing them is those collector bolts can be very stuck. And can even snap sometimes. So changing those is always a last resort.