SlammedRanger

Yes stock guides work perfectly fine. The chain actually fits tight between the side walls and i have been running one in my quad for 5 years with 2 rebuilds for power upgrades between. Have checked guides both times for any wear and they are like new. As for the crank wrist pin having a roller bearing. I think years ago gt thunder and poweroll were doing that upgrade. But all stock and aftermarket cranks and rods for this quad made today do not. Just a brass bushing. It is a constantly oiled bushing though so as long as the oil hole up the rod doesnt clog up it should have no issues from that area. Most used quads sold today have been rode hard and put up wet. And ran out of oil many many times. Luckily this particular quad can handle that for a good long while before getting real bad.

LoL. Yeah i have just about everything you can put on a 400ex from a 450. All my brakes front and rear are all 450r. The master cylinders and everything. Im running a yfz450r carb. My nerf bars are designed for a 450r. Axle and swing arm are 450r. My hood is 450r. I have a custom subframe that is made to work with 450r grab bars. The list goes on and on haha

Nope they dont have measurements or spec's anywhere. If you go to the crf450r timing chain you will never need another one. Believe me it will be the last timing chain it will ever need. But if you are dead set on measurements i would measure the new one you get and compare them.

No car a/c's have what is called an accumulator. Probably spelled that wrong lol. But the theory behind that is when the rpm's are spinning super fast it doesnt just get like super crazy cold a/c. Since the compressor on a car is directly effected by engine rpm. A txv is an adjustable metering device. It meters the liquid refrigerant back into the condenser to turn back to a vapor.

There are two types of metering devices. So when the refrigerant turns from a gas to a liquid it is metered through a small orifice. There are fixed metering devices called a "piston" or there are "txv" metering devices that are adaptable. So they will be able to make up for under or over charge systems alittle bit. And they can actually adjust when it is required for more or less cooling capacity. So if you have a txv in theory if it required it to open all the way sayinf it was really really hot and humid if it was undercharged it could then freeze up trying to keep up with the exessive heat and humidity.

I would bet my last dollar the crank is completely fine. The blue on the rod is 100% normal. If there was no up and down play in the big end it would be good to go. Your knocking i would almost guarantee was a stretched timing chain. While you are doing this rebuild i suggest doing the crf450r timing chain upgrade. Requires no modification but is alot stronger then the factory chain. If you have any questions feel free to hit me up! I have alot of custom mods done to my quad aswell. But not that type of custom lol

Sorry guys. Was at disney world with the family all last week. Just got home yesterday and have been in recovery mode lol. Ice on the indoor (evap) coil can be caused by just a few things. Low refrigerant charge/ excessively clogged air filter or air flow restriction of any kind/ or it can happen of the condensate drain clogs. I have had condensate drains clog and un-clog themselves before. But i would bet you are getting lower on refrigerant charge. If you have a txv metering device on your system it is possible to continue to work again for short periods of time or until it gets really hot and humid again and not be able to keep up. My .02

Around where i am it will cost 25 bucks a bolt? I know other places its different. But i used head brings a whole laundry list of other possible problems doesnt it? Never looked at utility quad head prices but sport quad heads are around 200 dollars used. Seems aggressive to me?

I would take it to a machine shop. Those bolts are a harder material then the cast aluminum the cylinder head and jug are made of and your drill will walk off and end up crooked. Any machine shop will use a drill press and center it perfectly. Drill and tap it to the next size and put a heli coil in it. My .02

Welcome aboard!

Welcome aboard!

I stay signed in all the time aswell. But anytime i clear cookies and history on my phone it logs me off and i have to sign back on. Has happened since day one and its been every single time. Only issue i have had from time to time is the site freezes and i cant scroll. But that has happened on multiple other sites and is always fixed with a cookie and history clear.

Ill be the first to say if i had a huntsman spider fall on my lap while driving it wouldnt be the crash that killed me. It would be the heart attack that happened before the crash. Glad you got it sorted! Have fun out shooting!

Oh gotcha. Yeah thats what i would do for sure. All balls is a china kit and they are well known for cutting corners in manufacturing. There seals and jets i would think will be close enough to work fine. But the float and anything else i would avoid for sure! Float level can effect alot of things. And doesnt always run out the carb or the overflow tube. Just a very minor adjustment can result in very rich or very lean condition.

Welcome aboard! What kind of rebuild kit did you use? I have found alot of the cheaper kits are good to use everything but the float. And it certainly sounds like a float level issue to me. My .02

Ran k&n for years. Properly maintained with all the right cleaners and oils. Followed directions to the T. Would take a white towel and wipe out the intake tube (passed the filter) before the carb. Would come out brown or black depending on the riding condistions. Went to uni. I use oxyclean laundry detergent in the sink to clean it. Use the proper foam oil. Have had clean white rags ever since. The k&n is slowly (and i say slowly because it will take a long time) sandblasting your combustion chamber. I have 3 uni filters total. And i will change them mid ride if i absulutely need to. But i just keep them oiled and ready in a zip lock bag. My .02

I always use brake parts cleaner on motor internals. Gears and case halves and things. It will evaporate 100%. And if i plan to let any of it sit i will hit it with a light coat of wd40 to keep the surface rust monster away. Always works good for me.

Im trying to figure out how its not running on the rev limiter? Unless you did one of those cdi boxes that removes the limiter. Wide open throttle for 2miles would be banging the limiter the whole entire way. I will say from experiance the 400ex motor built right will handle anything. Stock form with out a limiter the valves are floating hard and it wont last very long before your pulling a piston with a valve sticking out of it from the engine. My .02

Heck yeah buddy! I have zero idea about 3D printing aswell. Sounds like a blast to learn it! Im sure with your computer ability you will be making all sorts of crazy things in no time!

Man when you start talking multiple gears on one shaft i am lost. I will say if you go smaller on the engine it increases torque and lowers top speed. Its the opposite on the axle. The bigger you go on the axle the more torque and less top speed. Changing on the axle also changes your mechanical advantage over the tires. Which will adjust your traction as it will want to spin the tires easier. Where changing the gear on the engine side it isnt as noticable.

Welcome to the forums! Seems someone beat me to moving your thread to the proper section. Im sure someone will be along to help you shortly. Im a sport quad guy so my utility quad knowledge is limited.

The xr650 is designed very similar to the xr400. Which is the same engine as the 400ex. I would bet the ticking is the auto decompression. The reason its in the first 20 seconds is it works on engine rpm. Uses centripital force to drop into its groove and stop ticking. I would bet if you rev it and hold the idle high for a few seconds you would hear a click and it would stop. That would confirm it 100%

I agree 100% about the drill bits. I have a good machinist set

I guess i just know when to back out the tap to clear the shavings? I have never in my life come even close to breaking a tap off in a hole? If the tool is used correctly it should take almost no force to tap any hole. And by correctly i mean use the size drill bit that is stamped on the tap itself. Anyone using the wrong size drill bit cant blame the tool for breaking. Honestly the machinist drill bit set is more important than the tap and die set. IMO

I will tell you bud. I have an old chraftsman standard set. A pittsburgh metric set from harbor freight. And my buddy has a snap-on set in his tool box in my garage i can use anytime. If you picked a few pieces out of each set and switched them around there is no way you could ever tell. They are all 100% identical. And unless your using them everyday all day long the chances of you breaking one or having any problems is slim to none. 2 if them have a lifetime guarantee on them. The chraftsman kit is atleast 30 years old. None of them have a broken piece anywhere in them.