I have been trolling here for some time but now i need some advice, i try and give the whole story so i dont waste peoples time ! and hope i can get some where with this atv.
For me its sentimental thing so i want this to run but not go broke lol
History: 84 Lt125 i grew up on, it ran before i put it away 2-3 years ago and also i ran it time to time during the summer just on the driveway, note the normal stuff, little smoke, hard start need choke has to be on. So i put it away casue the primer plunger broke, caped it but was extremely difficult to get going so i left it alone till just recently.
Picked up a carb kit,plunger and then a float after i realized it had holes,, set up to spec but wont idle. Got frustrated with all the fuel being dumped into cylinder and could not control it flooding so i bought
a NEW carb oem.
Ok so new carb, new plug, good fuel flow from pump (seems ok), spark is strong looks blue in dark light lol, compression 180psi, re set valve chain tensioner, ckd for vacuum leak between carb and head none found, oil level good, fuel is fresh prem and tank is spotless clean, i cant get it to idle and its driving me frigin nuts just doesnt make any sesne. It does smoke heavy now i guess from sitting but b4 i replace rings and seals i want to get it to idle, seems power is ok when i rev it up just wont idle without finger on throttle.
I have the oem shop manual, im a lic tech for over 20yrs lol but i cant figure out this simple engine what am i missing GUYS !!!
Not sure i should remove head cover and inspect timing correct
any help will be greatly appreciated , thanks for taking the time to read this all

Tom

 

OK it never fails but this post i made should help other allot !!!!!
After spending $$$ and countless hours searching on the net i read the above sticky post LT80 idle issue and and they posted about the fuel petcock failing internally and sucking in fuel (i dont have one on my 125) and im like DAMN i ran to garage started up machine shut it down pulled off vacuum line at pump and sure enough fuel came out. Started it back up and plugged line with finger and bam it purred
actually angry with myself i never clued in but i work on cars and not small engines
well i guess its a easy slip but very difficult to diagnose even though i new darn well i had excessive fuel but just assumed it was my carb duh .
Researched and no rebuild kit found but i cross referenced same pump as LT4WD LT-250 quad runner and ebay has lots available. Note i will confirm and update post in a week when i get kit and test fitment and operation, dont feel like spending 100$ for a pump when i spent so much on a carb i obviously didnt need.
Hope this helps others

Tom

 

If it's one of those aftermarket Chinese carbs you might want to go through it to see if the jets are open,passage ways are clear and jets are also the same size as the oem carb. Plenty of people had more problems after they installed these carbs than with the oem carbs.

 

Thanks for reply old polaris tech !
I spent the $$ and went OEM but it ended up being the fuel pump vacuum side sucking in fuel from the diaphragm that one thing i never checked. Rebuild parts on order and when i confirm repair i will report back, 100% this is my problem

 

Well good news my rebuild kit came in from ebay note not oem quality but im sure it will give me a few years of service !
Rebuilt pump installed and first crank and shes purring hope this helps others.
I just pulled the motor out this evening (after pump inst) taking it into work for a tear down. Gasket set on hand, replacing rings and diagnosing my reverse issue im having. I need to tear down case (scared lol) and look at my reverse idler gear, on hard acceleration it wil grind hard in reverse. I have tried adjust the throw but did not help if any im hoping its just a easy swap out reverse and im done.

 

It’s 2019 and it helped me a lot! I’m building a 85 lt125 for my granddaughters and could not figure out the problem fuel leaking from the pump into the intake manifold never occurred to me . THANK YOU!

 

awesome