hi im new to the forum but have been browsing for a while now! i have read a lot about lt80 idle issues but nothing that has really been comparible to what i got going on im frustrated and at my whits end! so the what it does is, it fires rite up w choke on, idles all day long if i give it gas it will move but will bog out w choke on! if i turn the choke off it will run for maybe 20-30 sec. then idle goes down and dies! with choke off it will not move just bog out and die! ive cleaned the petcock i rebuilt and cleaned the carb! i sprayed carb cleaner around the fly wheel by the seals and it seemed to only bring up the idle w the choke off but dies like 5 sec after! i replaced the crank seal and still does the same thing! like i said im at my whits end w this thing but i really dont want to give up on it! any help would be greatly appreciated!

 

I'd do a compression check.

 

i did compression test and im pretty sure i had 110 psi! i also replaced the other crank seal today on the clutch side and still no change! i picked up another parts machine and im gonna try swapping carbs and see if that changes anything idk what else to do!

 

How about the carb o-ring? It there?
Try the spray around the carb area.

 

ya the o ring is their and i sprayed all around the carb! im stumped! lol

 

omg good news today! finally! i changed out the crank seal on the fly wheel side agian today and swapped out carb from my parts machine and now runs like a champ! man ive been working on this thing for months now and im finally done! thank you lt80 for your help much appreciated! im just glad its done man this thing rips! i mite even rebuild my parts machine! needs crank bearing though!

 

Don't feel overwhelmed about doing the crank bearings, they are pretty simple and the cost are cheap. If you already changed the crank seals before. Then you already have everything that you would need to do to split the case. Then the next thing to do was 5-6 bolts on the stater side to split the case. Don't forget to remove the head and cylinder. before you try to split the case. What I used was a socket that was almost the same size and tapped the bearing out and simply tapped the new ones in then replaced the crank seals. I just totally rebuilt my KFX80 and never doing a job like this before it was cake! I had ALOT of help from Jack-LT80. I can't thank that man enough for all the help. He is the best!! Well best of luck with the rebuild. Keep us posted if you need any help.

KFX80Dad-Rob

 

ya if you have any more tips on doing the crank bearings that would be greatly appreciated! like should i lay the motor on one side or the other so everything stays in place or do i have to take all the trany parts out anyway? im pretty handy w these small engines but ive never done this specific engine and to be honest ive really only done top end rebuilds and a few seals! ive split cases before but only on junk motors just to see what its like on the inside! i never put one back together so it should be interesting! cant wait to get started! im really excited! and i appreciate the support! thanks