shadetree

from the looks of the top of the piston pic you posted ^^^, that is a ton of oil burnt on the valve area. when you rebuilt the top end, what kit , as in..did you use the complete kit, piston, rings, cylinder, all new ?, if you just used a new piston with new rings, and just used your old cylinder ?, then that maybe your problem. a worn connecting rod wont be good either. any time i rebuild a top end, i make sure the rings fit the cylinder, by pushing them each down into the cylinder to check for fit, if the end gap is too much ?, it will smoke !. its also very posb you bent a ring while installing the cylinder down on the piston. one thing i have learned in all my years of working on atv's and rebuilding engines ?..DO NOT RUSH THE JOB !.

i'm not much for pieces falling apart ( once they do ), but that one piece looks like it may have came from the electric shift motor brush ?, don't qoute me on this !..lol. i tend to stay away from any electric shift motor atv, as i have found out, they are more trouble than what they are worth in my book. a few things i can tell you about them when they don't shift i do know !. one: the angle sensor is ( or was ) one of the big down falls. second: the shifting shaft is a weak link to the shift drum. last but not least, the ecu/c.d.i. has been known to cause problems on electric shifts..but not many.

i must say, in all the new oem grips i have installed on my rebuilds ?, not once have i ever used any kind of glue to keep the grips from turning, slipping off. maybe its because i paint the bars thick enough, it does not need any glue ?. i just spray the grip's inside with some wd-40, a tad on the bars, slide them on, done deal.

3-4 psi tops !.

a clogged fuel injector will make it run lean. check the air filter too.

i'm all for oem, never would i '' jerry rig '' wires on my toys. if funds is an issue ?, then just install a fan bypass switch, be done with it.

lol, sounds like some of my worst days from the past eh ?..lol.

9 out of 10 times, a red hot exhaust tells me the engine is running lean ?, or the exhaust system is stopped up ?. chances for either are 50-50 shot.

he can't ( or shall i say , shouldn't ? ) run anything larger than 25's on this atv, least not without rubbing fenders without a lift kit ?, and lift kits on these do not work well over time. i had to mod the rear fender on my '89 trx350d, 25's were to big, would rub the inner rear fender, had to move the foot guard forward..remember ?.

maybe my eyes are worse than i thought ?, but why do i see dark gray sealant on the starter cover ?, and dark gray sealant around the gasket and where the wires come out the top of side cover ?. yamabond is NOT dark gray, did you use rtv sealant ?..cuz it sure looks like it to me.

answer: TOO MUCH TOP END PLAY !. and too much side to side play as well, rod is bad.

RMATV has both the upper steering bushing, and lower steering bearing in stock, i'd advise you to buy them !.

i have not checked to see if the steering bushings are discontinued lately ?, but i can tell you this, the upper bushing , if it is discontinued ?, do what i did, i took a bearing race that matched the outside dia, then used my dremel with a grinding stone, and made the inner dia to fit the steering shaft, yes..it took over an hour to grind it..because they are tempered..lol. but it was worth it..that steering bushing now will never wear out !..lol. as for the lower steering bushing bearing ?, same thing..not sure if its around as well ?.

haha..i've seen folks on ladders, have the ladder on the other side of the cutting..yep..real winners i tell ya !.

gar ?..lol...you should come up here next year, i'll let you catch all the gar you want !..rofl.

i'll chime this in one more time. here is how i do my valves: i remove the rear pull starter, this gives me access to the rear cage, right behind this cage , stamped into the rear cover is a raised arrow. now i look on the cage, i am looking for a line that is stamped into the tang, this line, lines up with the raised arrow on the cover. now i remove the site plug for the timing mark, i'm looking for the T mark, once this is in the site hole, i now pull the rocker box off, yes..you have to remove the fuel tank to get to the rocker box. now i remove the spark plug, this makes it alot easier to turn the crank at the back on the pull starter wheel. you will need a 17mm socket to turn it. keep in mind, when i am doing a engine rebuild ?, i am also installing a new cam chain, this area also has timing marks that need to line up, but in your case, you are not doing a new cam chain install ?, so you can not make sure the cam chain sprocket is correct. so, once my two timing marks are lined up. now i turn my pull starter as if its cranking over, in this case, clock wise as if you are pull starting it. while i am doing this, i am watching my valves, spec the intake valve !. i do a full 360 degree turn with the pull starter and socket, i make sure my timing marks line back up, now here comes the trickey part..i turn the pull starter BACKWARDS !, slowly mind you !!, as i am doing this ?, i am watching the intake valve for movement, if i had the piston on TDC ( top dead center ) on the compression stroke ?, then the intake valve SHOULD start to go down as i turn the crank backwards ?, if it does not ?, then this means i had the piston on TDC on the exhaust stroke !. have i lost you yet ?..lol. i'll make this simple. with the two timing marks lined up, watching the intake valve, as you turn the crank backwards , the intake valve will go down ( sooner or later anyway after a bit of turning ). if it does not go down ?, then go back clock wise, line up the line on the pull starter cage, now keep going all the way around until that line on the cage lines back up with the raised arrow on the rear cover..STOP !, now turn the crank backwards, as you do this..the intake valve will start to go down. when it does ?, STOP !, now turn the crank clock wise until you get that line lined up with the raised arrow, STOP !. now you are on TDC on the compression stroke. loosen the valve nuts, adjust the valves. put it all back together. this is how i've done it for years..and to this day, it have never failed me !.

welcome. my first 1989 trx350D foreman 4x4 ( that is still in my yard ! ) will never be sold !. this is where it all started with my hobby ( 30 yrs ago ! ). i've had my hands on a lot of these models...and i'm here to tell ya..they are tanks !. with that said, they also require parts..and new parts are being harder and harder to locate !. and when you do find new parts ?, YOU BETTER HAVE DEEP POCKETS !..LOL. do yourself a huge favor..don't go messing with a good design, by this..i mean keep it simple on upgrades. leave the front end alone..it was designed the way it is for a reason, its called limited slip..and this will make it alot easier to ride in tough spots. DON'T GO LIFTING IT..AT ALL !. the front swing arm can only swing so much, after the point of no return, you run the risk of tearing up the fenders from to large of tires ?, or tearing up the drive line ?, trust me..drive lines for these are getting VERY hard to find these days !. you can put 25x8x12 tires on the front, and 25x10x12 tires/rims on the rear..WITHOUT A LIFT KIT !. my '89 trx350D foreman 4x4 has this on it right now, no issues at all !. you will have to move the foot guards from rear fender up further to clear the tires ?, but its not much. i have a thread in the brake section ?, or the custom section ?, where i put a high lifter disk brake kit on the front. you can also use atv super brake disk kit as well ( seems high lifter is putting china parts in their kits now ! ), you will need some 1/4 steel plate for spacers for the mounting brackets, you will also need a trx420 front brake master cylinder, the factory master cylinder will NOT work with disk brake kits.

i was gonna leave out friday night for the deer woods, and try to get one more hunt in, but after watching the weather channel ?, i decided to head out sat morning. it got really bad here storm wise, rain, wind, thunder, all that. so stayed home friday night. did get a text from bcs, let him know i was ok, and just got to the woods sat morning. prayers to all that went through this tornado !.

welcome. you say you have read alot on here of some hating on es ?, well, in time, you will find out just how bad they really are !..lol. been working on atv's for 30 yrs, i've seen my share of es problems...just as you will !, bank on it.

if it's not the reg/rec ?, then its the stator.

with multi-tester set on 12vdc on battery, run engine, watch meter, it should climb to around 13-15 volts when rev'ing.

answer: the timing is off, maybe from a jumped cam chain ?. or a bent valve ?, or not enough compression from worn rings ?.do this test first, take a can of starting fluid, give the carb a SHORT burst of it, if it fires off them ?, then its a fuel issue, if it does not ?, then this leads me to think its a timing issue ?, or bent valve ?, which leads to not enough compression to fire off.

umm, i hate to be that guy ?..but both the 450es and the 450fm/s have the same transmission. what is different is the shifting shafts, one uses a motor and transfer gears to change gears, while the fm/s models use a shifting shaft that is different, and uses a foot operated lever to change gears. both have the same transmission in them. also, the electronics are different. unless they changed them in the yrs in production that i am not aware of ?, both engines are almost the same over all.

good luck, keep this thread updated on what you find out !.

utility atvs are not, were not made to set land speed records for the this, move up to sport quads, utility atvs will never do this. ( least not without deep pockets ! ).