Popa Fry 62 Posted July 1, 2022 I had found the exact prices from both ... 1/2 price from PSN now i hope i can find the cause before i lose another CDI .. If the stator is putting out ( i know this is AC current) and the Regulator is doing its job and can be checked at the battery at 14.5 / 14.2 ....is it possible for the Stator to be putting out to much current into the system or does everything go thru the regulator ???? worried i have not found the problem .. I know this question sounds redundant it runs so Good until i lose spark !!! Share this post Link to post Share on other sites
Fishfiles 20,145 Posted July 1, 2022 I am not the one to answer your , what happens if there is too much AC voltage question , @shadetree , @retro or @Melatv could tell us --- personally I don't think it could over produce AC current , but not sure totally different animal but -- I have had my 300 putting out too much DC volt , it would blow the fuse as soon as it was rev'ed up , as long as you did not go high rpms it would sit there and run , it was the regulator that was bad in that case I would hope your original CDI was bad , you replaced it with a chinese knock off that did not last , so a new cdi is going to fix the problem Share this post Link to post Share on other sites
Popa Fry 62 Posted July 1, 2022 Sir I appreciate any information you can provide I am an Engineer by trade and I worked for my father in a Garage for 12 years so i have some basic knowledge .... that said this is relative new to me i found and old Polaris 500 that wouldn't shut off and rewired it new CDI New Voltage.. Rebuilt carb cleaned it up and got an offer i could not refuse ..... bought trx300fw.. carb kit rework rear brakes including axel and it is running very well.... it is for sale when i get this 400 FIXED...... THANK YOU ALL SO MUCH for your help i found a way to test the CDI on line for shorts not sure that proves it is good ??? the original appears to be good Confusing right....wait until Tuesday get new CDI and try it out...rebuilding this complete was a challenge but the way ir runs is satisfying if i can only keep a spark lol Share this post Link to post Share on other sites
Fishfiles 20,145 Posted July 1, 2022 please share that cdi test link. My story is a lot like yours I had a Polaris 500 Sportsman giving to me once. Lots of work and money into it. Ride twice and work on it once kind of ATV. The starter bendix blew and took out the $550 dollar stator. Ricky Stator helped me out on that one. Traded it for a 450. Spent too much time and money on it. But I’m afraid of it. Don’t want to break it so I seldom ride it. Got into 300s. Best one Honda ever built with 4 wheels. 1 Share this post Link to post Share on other sites
Popa Fry 62 Posted July 2, 2022 This is the best i can do: in google typed in is there any to test a CDI unit for Foreman TRX400fw ( listed below on page ) How do I know if my CDI box is bad? this is a YouTube Share this post Link to post Share on other sites
Fishfiles 20,145 Posted July 2, 2022 Here are a couple of videos that came up using your method of search Share this post Link to post Share on other sites
Popa Fry 62 Posted July 2, 2022 The first one is what i used....this test checks for a short between the ground and the post as i understand it 1 or 2 post side beside are ground (or empty ) one for coil one for alternator power one for key and one for pulse (not sure what that is ) Like i said this only shows there is no short between the ground and post not sure if that is a very good test Maybe this can help someone later.. i will know more when i get a new CDI and plug it in to see if I have spark ... I can check it before I install it and let you know later a THANK YOU Share this post Link to post Share on other sites
retro 4,048 Posted July 5, 2022 I would suspect a poor frame ground somewhere (one of them may be getting rusty/corroded under a wire/cable connection bolt) if I suspected there might be a high voltage issue causing the OEM CDI to fry? But if a China CDI fries thats normal and expected, they are all complete garbage. So before ya run your new OEM CDI ya might wanna pull the negative battery cable off of the motor and frame, and pull the two wiring harness ground wire bolts off the frame and shine all of those up. Coat each shiny surface with dielectric grease when you bolt them back down to prevent future corrosion. 1 Share this post Link to post Share on other sites
Popa Fry 62 Posted July 5, 2022 THANK YOU it fried both an OEM and China CDI both failed when the engine was reeved up.... tested before they failed and had 14.2/14.3 to the battery THIS WAS AT IDLE .. ... i did put an aftermarket stator in during my overhaul and i am thinking it is some how over powering something and causing the CDI Failure i have an OEM rectifier and CDI unit but i have a China CDI to use to prove out the ruined first OEM if i plug it in and get spark OEM CDI fried i am afraid to put in the new OEM CDI even if i put on the rectifier and get the 14.2 or so battery output. with overhaul and carb kit this motor runes as good as any i have seen starts in less than TWO revelations. runs smooth and sounds great.. i want this fixed and i am about to pull the engine and put in a OEM stator//Correct me if i am wrong if i have CDI failure it is the CDI Rectifier or Stator am i missing something Per you suggestion i will double all grounds. Runs until I lose spark. You men do not have any Idea how much i Appreciate your help ... hope to have this 400 out and running and dependable. 1 Share this post Link to post Share on other sites
retro 4,048 Posted July 5, 2022 5 minutes ago, Popa Fry said: i want this fixed and i am about to pull the engine and put in a OEM stator//Correct me if i am wrong if i have CDI failure it is the CDI Rectifier or Stator am i missing something The china stator must be replaced with OEM as you know, china parts just don't work very long (or at all in many cases) on Hondas cause they're all chintzy garbage. But the stator function itself cannot fry a CDI.... a stator is just an alternator.... an AC power supply. The voltage regulator converts the AC voltage output from the stator into DC voltage and regulates that DC voltage so the charging output remains safely below 15 volts. OEM CDI's can get fried if charging voltage reaches/exceeds approximately 16 volts. So clean up all of the grounds first.... there are two ground wire bolts on the frame and one on the motor where the negative battery cable bolts down. Since you have it somewhat apart already if I were you I would separate every wiring harness connector on the ATV one at a time and clean them with brake clean spray or electrical parts spray, then put some dielectric grease inside each connector and around the rubber connector seals before plugging each of them back in. Finding water/corrosion inside of electrical connectors is common on Hondas, especially on older machines, as they are not waterproofed by the factory. So prepare those connectors now if you can.... to save you money and time, both now and later.... If there are any other china knockoffs on your Foreman replace them with OEM parts right away. Ya can't fix problems while garbage parts is still on the ATV.... Keep us posted on how things go for ya. Share this post Link to post Share on other sites
retro 4,048 Posted July 5, 2022 Also just in case that your wiring harness may be hacked up, spliced, or repairs attempted, replace it with a good used one. Hacked up harnesses kill a lot of expensive electrical parts. Share this post Link to post Share on other sites
Popa Fry 62 Posted July 6, 2022 thank you, i will let you know how it goes it will take some time to separate every plug these thing don" want to let go as you know never opened in 22 years ..... and need to find grounds on frame i will replace with OEM ASAP.. with local temp at 93 / 95 degrees I might be working late in evenings THANKS !!! 1 Share this post Link to post Share on other sites
Goober 1,555 Posted July 6, 2022 (edited) The aftermarket stator Does it have any extra connectors you didn’t need? Are the wire colors different? can you members remind me of the pulse generator’s role in this? The firing impulse (pulse generator) is triggered by the flywheel, and the CDI amplifies the pulse to the coil. Can the pulse be too strong for the CDI somehow? or dirty spark plug wire inhibit discharge? Edited July 6, 2022 by Goober Share this post Link to post Share on other sites
shadetree 5,864 Posted July 6, 2022 30 minutes ago, Goober said: The aftermarket stator Does it have any extra connectors you didn’t need? Are the wire colors different? can you members remind me of the pulse generator’s role in this? The firing impulse (pulse generator) is triggered by the flywheel, and the CDI amplifies the pulse to the coil. Can the pulse be too strong for the CDI somehow? or dirty spark plug wire inhibit discharge? pick up coil ( or more known as pulse generator ) is nothing but a trigger for the c.d.i. to tell the c.d.i. when to fire off the spark plug coil/spark plug. the flywheel has a raised metal piece on it that goes by the pick up coil on every revolution. 2 Share this post Link to post Share on other sites
Popa Fry 62 Posted July 6, 2022 plug was the same 3 yellow and 1 blur 1 green ...Update i received a new CDI (China I know( but the first one i got run good until it failed... for kicks i put the one i just received and although it started it runs like crap spitting and back fire i did get it to idle long enough to check the voltage on two different rectifiers both 14.2 i ma almmost convienced it is the stator or pulse generator... either way i need a new OEM Stator that should get me an amen !! Thank you all for the help i NEED itand appreciate you advise Share this post Link to post Share on other sites
Popa Fry 62 Posted July 6, 2022 Retro I am having trouble locating the Grounds you mentioned I have one bolt on the engine the has two ground wires attached heavy wire . .. i started at the back at rectifier and tail lights followed it forward up to the fan cdi control box for fan lights and I did not find anything can you give me a hint where i would find the additional grounds 2000 trx400fw foreman i looked at the wiring diagram but it doesn't help me Thanks men Share this post Link to post Share on other sites
Fishfiles 20,145 Posted July 6, 2022 If you look at #10 on this print , it is the ground , it is an either / or , you see how one wire is all one piece and the other is two wires , yours could be made either way , and the junction of that ground wire where is is two is behind the starter , same as my 450 which I see needs some washing in this pic Share this post Link to post Share on other sites
Popa Fry 62 Posted July 6, 2022 that looks similar to mine one from batt and other wire goes to the frame I JUST FOUND IT !!! AND ATTACHES TO THE MOTOR maybe that's all I have .. Share this post Link to post Share on other sites
retro 4,048 Posted July 7, 2022 On 7/6/2022 at 10:28 AM, Popa Fry said: i did get it to idle long enough to check the voltage on two different rectifiers both 14.2 i ma almmost convienced it is the stator or pulse generator Hi Popa, You have to rev the motor up high (a brief rev to about 4500 RPMs should be sufficient) when you check the maximum charging voltage. The stator (nor the pulse generator) function can not influence an overcharge voltage issue, only the regulator/rectifier function can. There are two frame ground wires. One is the ground cable that comes from the motor ground cable attachment location and bolts to the frame on the lower right/rear side. You can follow that cable from the motor to the frame with your eyes and hand... The other frame ground point is where the main wiring harness is grounded to the frame. There are two Green wires crimped inside a single brass Ring terminal coming out of that harness. The harness ground Ring terminal bolts to the frame under a single bolt. I don't remember where that harness ground is located on a 400 Foreman though.... look for it near the motor-to-frame ground bolt location, or on the front/left side of the frame where there are several harness connectors attached to the frame. I'll attach a couple images with Red arrows added that may help you find them... maybe someone else remembers the location and can help ya. 1 Share this post Link to post Share on other sites
Popa Fry 62 Posted July 7, 2022 I had found and cleaned the one from the motor to the frame on the outside of the frame per first print out!... and with the help of the second I FOUND IT under the harness .... it actually has two terminals each with 2 green wires.. SIR You are the Man I would like your thoughts on what could Blow a CDI other than a faulty rectifier. i did get it to rev up not sure to what RPM but the voltage remained 14.2 with 2 different rectifiers the one that was on the atv at the time of the CDI failures checked good but i had two CDI units fail like mentioned before i put a China a Stator in when i rebuilt it I am getting an OEM from Power Sport Nation to put in motor.. Sure wish i could do that without pulling the motor. You Men contribute so much to the Honda community not to mention helping an Old Man fix his Ride THANK YOU Share this post Link to post Share on other sites
Fishfiles 20,145 Posted July 7, 2022 41 minutes ago, Popa Fry said: Sure wish i could do that without pulling the motor. I'd tell you the stator can be changed without pulling the engine out the frame Share this post Link to post Share on other sites
Popa Fry 62 Posted July 8, 2022 do i need to loosen the mounts and lift it up for Clearence and remove skid plate Share this post Link to post Share on other sites
shadetree 5,864 Posted July 8, 2022 28 minutes ago, Popa Fry said: do i need to loosen the mounts and lift it up for Clearence and remove skid plate drop the skid plate ( remove it ) then remove the stator case, it should just come right out after you remove all the mounting bolts. Share this post Link to post Share on other sites
Popa Fry 62 Posted July 13, 2022 ALRIGHT MEN I am back UPDATE: removed aftermarket Stator and replaced it with an OEM Sator ..put on OEM rectifier ...and OEM CDI unit i got the parts used from Power Sport Nation (someone suggested them it the previous Tread. so i start putting everything back together .... first check before i go to far I checked for spark... It had a very strong Spark arc..... so finished putting most everything back together..Cjhrecked the battery 13.1 DC volt stand alone measurement ... NOW COMES THE QUESTION : ...when i started it it runs smooth appears to be back the way it was running before i lost Spark.. CHECKED THE DC VOLTAGE AT THE BATTERY AT AN IDEL AND HAVE A READING OF 14.6 / 14.7 BEFORE I HAD READINGS OF 14.2 / 14.3 IS 14.7 TO MUCH ?? IT IS AN OEM RECTIFER.... ALSO TO MY SUPRISE IF I INCREASE THE RPM TO WHAT I GUESS 2000 RPM THE VOLTAGE ACTUALLY DROPS TO 14.5 Thanks in Advance i know you wil keep me straight. I do appreciate your input Thanks 2 Share this post Link to post Share on other sites
Fishfiles 20,145 Posted July 14, 2022 Good news ----- 14.6 -14.7 will be ok --------- now don't go running off since your atv is running , stick around --- and tell us about your 4 wheeler adventures you can be the guy , that ask the new members asking for help , if they used OEM parts and if they have China parts , they should get them off the atv before continuing , LOL 2 Share this post Link to post Share on other sites
