400EX questions - Honda ATV Forum
Honda TRX Discussions for the Honda TRX, 90, 250, 300, 400, 450, 700

 9Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 73 (permalink) Old 03-26-2019, 11:28 PM Thread Starter
Member
 
Austin92's Avatar
 
Join Date: Mar 2019
Posts: 61
Liked: 6 times
400EX questions

I’ve owned my 2000 400EX about a month now. Got it bone stock with only issues (I thought) was leaking carb and toasted rear axle bearings. I’m still not familiar with good brands and ones to stay always from. I ordered a complete carb for 48$ and complete axle bearing carrier for 35$ off eBay.

I also ordered an uni filter, hmf performance full exhaust and a DynoJet kit+42 piliot jet.

With everything installed I was very happy with it except gearing so I dropped from 15/38 to 14/39 with a new gold oring chain, all from primary drive. I knew they are cheap but I wanted to test the gearing before I dropped cash on nice gears.

Problems:

Hmf’s head pipe is a different shape and my clutch cable was laying on it so I went and got some of those spark plug heat sleeve things for it but it’s still making the cable stick after a hard ride and cool down.

With the new carb, I put in the DynoJet needle to same length as stock. 170 main, 42 piliot, and about 2.5 turns out on the idle screw. It won’t start with out choke and even after warm has a weird idle. Sometimes it idles high, other times it barely idles and dies, usually high then starts to drop until it dies. It doesn’t pop through the exhaust on deceleration but I noticed about the first 1” of the head pipe starting to turn orange when riding at night. It doesn’t bog or blow black smoke so I think I’m pretty close on the jetting

And here’s the big one that I’m all butthurt about lol. I rode for about 2 hours Saturday, moderately hard on it and it did great, no issues. Sunday I took it to my dads, he went first and babied it 1st through 3rd. Came back, shut it off, we talked for a few minutes. I got on, started fine and I ripped on it 1st-3rd, when I let off he said it shot a flame out the exhaust and a few seconds later it died when idling. When I started it back up, it sounded like it had something rattling/slapping in the engine, not the trans for sure. It was low on power and every time it made that slapping sound, maybe timing chain?, it would miss, catch it’s self and repeat. Throttle made it worse. Full on oil, no metal on the dipstick, not hot. Drove the truck to it and pushed it up the ramps.... when I got home I checked the valves, they weren’t loose so I pulled the cover, no rocker arm damage, cam looks good but I’m not sure how the timing chain should look/feel. I was thinking about ordering a stage one hotcams since I’m already that deep and it includes a chain but I don’t want to rip the clutch cover off if I don’t have to.

Sorry for the long post, I’ve been procrastinating making an account here
Austin92 is offline  
Sponsored Links
Advertisement
 
post #2 of 73 (permalink) Old 03-28-2019, 09:48 PM Thread Starter
Member
 
Austin92's Avatar
 
Join Date: Mar 2019
Posts: 61
Liked: 6 times
Take it thereís not many 400EX guys on here? Lol


Sent from my iPhone using Tapatalk
Austin92 is offline  
post #3 of 73 (permalink) Old 03-29-2019, 06:47 AM
Super Moderator
Supporting Member
 
SlammedRanger's Avatar
 
Join Date: Feb 2010
Location: Norwalk,OH
Posts: 4,168
Liked: 1195 times
Garage
Sorry bud. I over looked this one. Im gunna have to read your whole post though and i cant do that at work. I will get back to you with an answer later.

07 416ex
To many mods to list in signature(ran out of space lol)


Check out garage for full list
SlammedRanger is online now  
Sponsored Links
Advertisement
 
post #4 of 73 (permalink) Old 03-29-2019, 06:01 PM
Super Moderator
Supporting Member
 
SlammedRanger's Avatar
 
Join Date: Feb 2010
Location: Norwalk,OH
Posts: 4,168
Liked: 1195 times
Garage
Answer to question number one. Stay away from cheap carbs. You want to only use the oem carbs on these quads. The aftermarket ones will generally have all kinds of issues. They are better used as a paper weight. You will be much much better off buying a moose or shindy carb rebuild kit and rebuild the oem one. Bearing carriers dont really matter the brand. They all wont hold up real well. I have a lonestar carrier and i run national bearings in it i get from the autoparts store. They are the same bearings as an a/c clutch bearing on a car or truck. I also buy special triple lip seals with spring garders from a local electric motor place. They are far better then even the factory seals that came in it.

Dyno jet kits are junk. Another paper weight scenario. You can jet with oem jets and do just as good or better and spend 1/3 the price.

Primary drive is actually not bad. I have been running there sprockets for quite a while. I just recently upgraded to a RK z-ring chain. But i had 2 full seasons of riding and racing on the original o-ring primary drive chain.

More than likely the reason your clutch cable is resting on the head pipe is because you are missing the cable holder that should be a metal loop that should be held on by the front motor mount bolt. Should look like this.

Look at this on eBay
https://rover.ebay.com/rover/0/0/0?m...2F173576551709

The rattling noise is very concerning. Expecially with the loss of power. The timing chain slapping will have no effect on power. Unless it skipped time. Which at that point more damage is almost un avoidable. Kinda sounds like a rod bearing let loose to me. That would cause lack of power and a noise. You also wont get metal shavings on the dip stick. Not unless you have all the oil full of metal which wouldnt really ever happen. To see that you would have to drain the oil. Hope this helps!
XplicitRacing6 likes this.

07 416ex
To many mods to list in signature(ran out of space lol)


Check out garage for full list
SlammedRanger is online now  
post #5 of 73 (permalink) Old 03-29-2019, 07:09 PM Thread Starter
Member
 
Austin92's Avatar
 
Join Date: Mar 2019
Posts: 61
Liked: 6 times
Itís ok, I was thinking if there werenít many guys into the same quads I like, Iíd try like trx forum. I do appreciate the info.

Iím on oilburners.net and I know my way around those trucks very well and can point new comers in the right direction on stuff like you said on the carbs and jets. Now Iím the new comer here lol.

I didnít know my hmf exhaust was going to come with jets. They are hex like the stock where the DynoJet kit is round with the adaptor. Would the hmf jets be better? My 42 pilot is Honda though. The cheap carb was just to keep gas off the quad and garage floor, I do have intentions of rebuilding the oe one.

My quad does have the little loop for the clutch cable but the hmf head pipe is bent different than stock. Iíll have to get a pic for you later

I think I found what was making all that noise last night when I pulled the clutch cover off last night. and it wonít let me post a picture.... I think itís piece of a piston skirt and when I drained the oil it smell like gas. So with that said, 416, 426, or 440? Lol

I also wanted to post a picture of my cam. It has a ďHĒ stamped in it and I was wondering if it was for Honda or hotcams. I donít ďthinkĒ I see the decompression valve

Thanks again for the help


Sent from my iPhone using Tapatalk
Austin92 is offline  
post #6 of 73 (permalink) Old 03-29-2019, 07:50 PM
Super Moderator
Supporting Member
 
SlammedRanger's Avatar
 
Join Date: Feb 2010
Location: Norwalk,OH
Posts: 4,168
Liked: 1195 times
Garage
No worries. There arent alot of 400ex guys here. But plenty enough to stick around. I would stay away from the 440 unless you are planning on alot of extra cooling mods. I like my 416 and its plenty competitive with 450s on the track. Straight drags not so much. But the reliability is hard to beat. The dyno jet to the oem jets arent really gunna make a difference one to the other. But the sizes on them are in a completely different scale. There are certain upgrades you will want to do to keep the big bore reliable. Gt thunder hd studs, crf450 timing chain, and cometic mls head gasket. That will get things started in a reliable direction.

07 416ex
To many mods to list in signature(ran out of space lol)


Check out garage for full list
SlammedRanger is online now  
post #7 of 73 (permalink) Old 03-30-2019, 02:30 AM Thread Starter
Member
 
Austin92's Avatar
 
Join Date: Mar 2019
Posts: 61
Liked: 6 times
Wouldnít mind doing some cooling mods. Considered the cfm oil tank, fan on stock cooler and adding another cooler. Planned on everything you mentioned except getting head studs from arp.

I tore in a little deeper tonight. Piston is fine but I found a small piece that was bouncing around the cylinder and couldnít get out. There is a mountain of chewed up cast aluminum under the oil pump pick up screen. There are blued heat marks on the crank next to the rod bearings, input shaft of the trans, and plates in the clutch.

REALLY didnít want to even get as deep as the timing chain, found that piece I thought was piston skirt and REALLY didnít want to do a complete top end, and now Iím ready to scrap it or spend 3k to build a monster 400EX...

I feel like everything I touch blows up. I donít abuse things and Iíd like to believe Iím not an idiot. Maybe itís bad luck.... lol


Sent from my iPhone using Tapatalk
Austin92 is offline  
post #8 of 73 (permalink) Old 03-30-2019, 12:34 PM
Super Moderator
Supporting Member
 
SlammedRanger's Avatar
 
Join Date: Feb 2010
Location: Norwalk,OH
Posts: 4,168
Liked: 1195 times
Garage
Oh its without a doubt bad luck. I beat the crap out of my quad everytime its started. Arp studs are expensive. And they dont really fix the problem. Just an fyi. The studs dont stretch. They pull the threads out of the jug. Gt thunders go deeper and use a bigger diameter stud. Arp just gives you a stud made of stronger metal. Hang in there bud. If you do the little extra work and money you will have a bullet proof quad.

07 416ex
To many mods to list in signature(ran out of space lol)


Check out garage for full list
SlammedRanger is online now  
post #9 of 73 (permalink) Old 03-30-2019, 12:40 PM
Super Moderator
Supporting Member
 
SlammedRanger's Avatar
 
Join Date: Feb 2010
Location: Norwalk,OH
Posts: 4,168
Liked: 1195 times
Garage
Also the heat coloring on the crank big end is normal. You will want to grab the rod and feel for any and i mean any up and down play. Grab hard and feel real real carefully. If there is any up and down play just change the crank now.

07 416ex
To many mods to list in signature(ran out of space lol)


Check out garage for full list
SlammedRanger is online now  
post #10 of 73 (permalink) Old 03-30-2019, 03:10 PM Thread Starter
Member
 
Austin92's Avatar
 
Join Date: Mar 2019
Posts: 61
Liked: 6 times
I have a magnetic dial indicator. Whatís the allowed run out for the rod bearing? So with those gt thunder studs, can that be done at home or is it a machine shop only deal?


Sent from my iPhone using Tapatalk
Austin92 is offline  
Reply

  Lower Navigation
Go Back   Honda ATV Forum > Honda Model Specific Discussions > Honda TRX

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda ATV Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in













Similar Threads
Thread Thread Starter Forum Replies Last Post
Xr400 gaskets on a 400ex, questions.. TorqueDaddy Repair & Maintenance 9 04-27-2017 10:02 PM
400ex questions about idle Mauriced9 Honda TRX 3 12-11-2016 07:19 AM
2001 400ex Modification Questions LittleRicky426 Honda TRX 1 07-26-2016 12:01 AM
05 400ex top end build questions ryans72ventura Performance Modifications 6 01-06-2016 09:14 PM
400ex piston questions official3d Performance Modifications 5 12-18-2015 12:21 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome