Carburetor Problems

[DeadBattery 6]

Recently got a big bore 440 kit for my trx400ex with a stage 2 hot cam, and I threw a amazon carburetor on there, everything else should be right, I gave it to one of my brothers buddy's and he said he was able to get it running, and I'm guessing he threw a different carb on there, because the guy said he could get it running with putting gas into the manifold, I haven't tried that yet but when I do get out to my old property then I'll try that, but I need some help with what jetting I should be running, I've mostly seen people running around a 180 and a 42, I think I have something like a 170 and a 42, and wondering if it's the carburetor itself or the jetting, since ive heard amazon carbs aren't it, and I don't have the old one, and I don't want to spend 200-400 dollars on an oem carburetor.

[SlammedRanger 1,556]

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.

[SlammedRanger 1,556]

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.

[DeadBattery 6]

Is there any company that sells an aftermarket carburetor that works good, that isn't expensive as the oem one, and I'll try a 45 or whatever jets I have, and use a 180 like you suggested, cause I have to wait for it to be delivered which will probably be this Friday or around there, and can I just buy an all balls rebuild kit if it is a bad carb?

Edited August 7, 2023 by DeadBattery

[DeadBattery 6]

Because I'm trying to spend as little money as possible until I get it running, and when I get it running, since it's pretty much a project. And this is totally unrelated, but the black crush gasket between the cylinder and the crankshaft looks like it's melted or something, I will try and take a picture next time I go out there, until I get some storage space in my garage.

[DeadBattery 6]

I put a 45 and a 180 in, it didn't start, but I sprayed starter fluid and still didn't even fire, so I'll check spark, but if it has good spark, what should I up it to, I only have a 180, but I have up to maybe a 55 give or take, which I doubt I would have to go that high.

[SlammedRanger 1,556]

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?

[_Wilson_™ 6,567]

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

Edited August 15, 2023 by _Wilson_™

[SlammedRanger 1,556]

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. 

[_Wilson_™ 6,567]

Dang! Wishe I'd known..... I used to haul grain over to waverly....the grainery is right next to the river.... Heck ya... lots of rain...I'm glad no we seem to be getting a real, just hope all those who need a good rain get it soon..... Let me know next time your down this way... It's not all that far to waverly... For a drive to meet a good friend. 

[SlammedRanger 1,556]

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.

[DeadBattery 6]

On 8/14/2023 at 7:19 PM, SlammedRanger said:

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?

I'm having a guess that it's the carb, since I sprayed starting fluid into the carb while turning it over and it popped, but idk if I would have to buy an oem, or a rebuild kit, sorry for the late response, I've been busy with other stuff. But everything else should be good since I've replaced most of the components since I've gotten the bike.

[DeadBattery 6]

And the battery was dead, so it didn't have enough power to actually turn it over, so that's why it didn't even pop.

[jeepwm69 7,611]

14 hours ago, DeadBattery said:

And the battery was dead, so it didn't have enough power to actually turn it over, so that's why it didn't even pop.

 

Username....CHECK.

[DeadBattery 6]

I ended buying one off ebay it was an oem one, or so it was stated, it looks like it has all the keihin logos on it, and says it's for a trx400ex and looks identical to it, but I couldn't read the numbers on it, so I'm hoping it's the right one, cause it was 165 which if it is the oem one or works then it's a huge steal, since ive seen some go for 200 bad condition all the way to 400 brand new, since I went to a shop the other day and they are saying that it would cost like 800 bucks which is insanely high, but it should get here on Friday the upcoming week, and I already bought am all balls rebuild kit for it.

[DeadBattery 6]

I got the carb, and it turns out the dude decided to break one of the jets, and I tried hitting it, but it's aluminum, so it's gonna break every 2 hits, and I was wondering what's the safest way to go about this, should I drill it out or what.

[SlammedRanger 1,556]

Jets are brass. Very very soft and easy to strip. Your best bet will be a small easy out. Twist it down into the hole and hope for the best. This very rarely ends well. Such a soft material its really really tough to not snap it or split it.

[DeadBattery 6]

Alright, I'll stop by harbor freight today and see if they have them, and what do you mean twist it into the hole, do I pick the the bit that fits the tightest and drill into the hole itself and then back it out?

[DeadBattery 6]

Can I just use regular drill bits, since the streets are flooded since the hurricane.

[SlammedRanger 1,556]

You need to get an easy out. You gotta turn it in reverse to get it out. If you use a normal drill bit it will just tighten it more. The easy outs will screw in but in the direction to remove it. The chances of you being able to drill it out by hand without a drill press is almost zero. You gotta keep it perfectly straight. And if your off by even a tiny bit it will be scrap metal. Not to mention all the brass shavings will be a nightmare to get out of it.

[DeadBattery 6]

Alright, my friend is getting some this Friday, and I'll probably work on it Saturday morning or Friday afternoon, I'll tell you what happens when I do it.

[DeadBattery 6]

I just bought them myself, but they're not left handed ones, so what should I do now.

[DeadBattery 6]

Nvm I got it out, I'll probably put it on my bike tomorrow after cleaning it out, and I'll tell you what happens.