SlammedRanger

Doesnt sound stock. My bet is the sound you are hearing is because its high compression. Its running pretty choppy. Im gunna bet it has a cam aswell. So that would mean no more decompression as that would only be with a stock cam. Needle isnt gunna have almost any effect on starting and idling. Needle is all mid and high rpm range. Have you pulled the plug? That would tell us how its running. Rich or lean. Seemed like you had it idling for a while there with very few revs so it should give us a good picture of how its running at idle.

Crap man. Didnt even cross my mind. I surely will next time we are down that way. Although i dont think we will do Lorettas again. That was checked off my bucket list. Next year it looks like we will be doing ironman and briarcliff here in ohio again. Sadly i think my racing days are almost over. Body is breaking down bad. I was gassed after one lap.

10 minutes ago, _Wilson_™ said:

Slammed ... pardon the Quick detour....  But are you talking Loretta Lynns ?? At hurricane mills tn ? 

Yep we were there for the final round of the atv national. It was a bucket list item to ride on that track and i practiced in the 30+ C class. Also went to nashville while we were there. Decided against racing as it was way to sloppy. Had alot of rain and storms saturday morning. 

Sorry spent the whole last week at Loretta Lynns for the pro atv national. If it doesnt even pop on starting fluid you got a spark issue almost no doubt. Start with that. If there is spark i would check compression next. Maybe timing chain is just broke? With all valves closed? Can you feel a pulse out the exhaust? Maybe the starter clutch is bad and its just free spinning and not actually cranking over?

Also any china knock-off carb is a hit and miss. Some will run ok. Some wont run at all. Some will run for a short time and then randomly decide they are done. There is never any consistancy to them at all. So they are essentially impossible to tune with the "this is what others are running" method. Every single one is worlds away different.

42 pilot jet isnt gunna be enough for a 440 kit. It will be a bear to get started even with the choke with a 42. I would start with a 45 pilot. And a 180-185 main sounds close enough it should run ok. 170 is way way small. 440 kits are sketchy to begin with. Dont want to take any chance of running them lean at all. They can seize in just a few minutes of running if not jetted correctly.

Welcome aboard!

I have a 26 foot toyhauler. With the ramp on the back. I personally like the ramp. Its easy and takes up zero room. I have ramps for when i load into my truck and the worst thing about them is they are too long for the bed and its always a fight to get them in a safe place. The ramp actually doubles as a porch aswell. Put some leveling jacks on the end and it turns into a nice platform extending the living space a bit. They even make side rails and doors and steps for them if you want to get real crazy. We have never used ours that way tho. Have had 4 full size quads in it tho. One of the best purchases i have ever made honestly. Having your own bathroom and shower. And bed when your riding places is a game changer.

With airbox removed like that its possible the 180 could be pretty close. If it had the airbox i would be guessing somewhere around 170. But your getting plenty of air with the box deleted completely.

Ok so topend has been rebuilt. It has a stock head pipe. Just a slip-on white brothers pipe. Airbox is removed entirely. Open filter. Carb is stock. I would get you a 42 pilot jet and pop it in. Put mixture screw at 2 turns from light seat and i bet she fires right up. If it has a 38 pilot(stock) with those mods it wouldnt start good if at all.

Main being 180 is alittle high unless its pretty built. Usually a 180 is good for a 416cc bore and a cam with a full pipe. Post some pictures if you can. I can tell you what you got mod wise from the outside. Cant tell internal obveously.

42 pilot if its stock internals. 45 if its big bore with cam. Stock would be 38 and the 42 solves the cold blooded issue. Makes the choke not necessary to start it. Welcome to the forums!

Welcome aboard!

At a buddy's practice track. Wife took a cool slow motion video of me riding.

Enjoy😏

I would start with the easy fix. Unscrew the yellow cap the plug boot comes off lefty loosey righty tighty. Cut about 1/2 inch off and screw it back on and test again. That is the easy and most common fix. If it doesnt you got just a few options. You can test coils. It is all about resistance. You gotta have a tester that can test for resistance. But my experiance is testing them doesnt really tell you much. I have had them test bad and be good. And test good and be bad.

Well the general rule of thumb is anything 100 or over will run. Maybe not perfect. But it should pop off. If starting fluid didnt get it to fire you most likely have a spark issue. Pull the plug and put it back in the boot and hold it against the side of the engine and look for a fat blue nice spark. If its orange or tiny there is your problem right there. I do suggest having a fire extinguisher on hand and ready. Just incase the engine has gas on the top of the piston and comes pushing out the top and it could ignite. At that point we can look into spark components.

On 5/31/2023 at 5:11 PM, DeadBattery said:

Yeah I wasn't sure, the jets had keihin on them too, but yeah I'll try to find a store near me that has jets, I'll try and run a 50-55 and I have a 170 already in the carb, but I'll try going up on the jets. But I think it might be the timing honestly, or it's just not enough compression, since i sprayed starter fluid in the intake manifold, and still wouldn't start, I heard niche is unreliable, but I don't think they would be so bad that you can't even get your engine started only after two starts.

If the jets had the K on them its a very good chance that is the oem carb. China carbs dont come with jets with the K on them or atleast not that i have seen. Niche is cheap. But i had a buddy that we put the piston and jug from a niche kit on his quad and it ran no problem at all for about 3 years. Now the concern would be if they sent you the wrong size piston or something. Not matched for the bore size maybe? We mic'd everything and ours was close. We did end up running a hone through the jug a few times as it was a tiny bit too tight for our liking. But would have ran im sure no problem.

Yep keihin would have been the oem carb more than likely. But even that isnt a guarantee anymore. China carbs have been selling with keihin and mikuni castings on them now. The only way to know for sure now is to go off the part numbers on the side if the carb body.

@DeadBattery i us jetsRus. They will have everything you need. If you had the oem carb i could tell you exactly what jets it has. But china carbs can be all over the place. You will have to remove the jets and take pictures.

Ok lobes facing down was right. Did you confirm the piston was all the way up? 4 stroke engine so you will see the |T at bottom dead and top dead center. If piston wasnt up at top you would have it timed 180 out. But it would have never ran at all that way. When its timed 180 out it will pop every single revolution and not start period. Not a bad idea to confirm 100% but if it ran i would bet its not that. My bet is the jetting is whats causing you trouble. I was running a 45 pilot when my quad was only a 416 with a cam. It wouldnt even run on a 42 no matter how hard i tried. Just like your having happen.

SlammedRanger checking in lol. Ok so since rebuild it started with a valve tick. Then stopped. You said it was timed a few teeth off. Thats very scary. These are interference engines. Meaning valves will hit piston very very easily. (Few teeth off). You may have gotten lucky with that. 110 psi compression is also scary low. But valves being adjusted too tight could cause that. Also could be a bent valve. Were gunna hope for the best on that aswell. When you timed it did you have the cam lobes facing up or down with piston at top dead center? (On the |T mark on the flywheel.) The carb is also jetted not even close. Your gunna be a 45 pilot jet minimum. Possibly a 48. And somewhere in the 180-190 range on main jets. With the 440 kit. Did you ever confirm where the metal inside the engine came from? Thats scary aswell. Usually metal shavings on these engines are crank failure.

Is the new starter doing the same identical thing? You can try taking the battery and putting jumper cables on it and touch a ground and a positive to the side post on the starter. If it turns over smooth then you only have wiring, the solenoid, and the start switch in between the two. I would personally never run 87 in any atv or dirtbike. 93 is minimum. Probably even says that in the factory service manual. How high of compression you plan to go will decide what fuel you use. (10:1-11:1) 93. (12:1-13:1) 100 or 110

After alot of research and saving my side cash i picked up a little pitbike to rip around the yard on and race the daughter on her trx90. Even tho it looks like a honda crf110 now. It is actually a 2022 thumpstar tsx125. Not a dirtbike guy and it shows. Daughter on her 90 can almost beat me around the yard haha.

Thats awesome THH! We all really appreciate that for sure! 1 more of many reasons this place is so great!

Sounds good! Keep us posted! We are always happy to help!