Chevymec 510 Posted December 24, 2021 I have noticed recently that my 2005 Foreman 500 has started smoking. Not when cold or it has sat for a few days, but when I drive to the hunting stand and sits for a few hours. When I start it up it smokes pretty bad. Park it and the next rime I start it up no problem. I didn't notice this until I changed the oil and filter a few months a go. Napa gold filter( installed the right way) and Valvoline ATV 10w40. Usually in the auto world I would say this is a drain back issue and oil sitting in the head and leaking by the valve seals but it will do it after a cold start also also. The motor was rebuilt about 1000 miles ago with a Web cam and Big Bore kit. Head was checked and jug was bored. Do these have a crakecase hose or some type of pcv valve? I did check the oil and it was low. I have the short dipstick and added oil till it was at the middle of the 3 hash marks not screwed in. Couldn't find my manual to check to make sure this is correct , but I believe it is. Share this post Link to post Share on other sites
Fishfiles 20,147 Posted December 24, 2021 My guess ---- Wallowed out wrist pin journal , egg shaped the bore on the bottom of the stroke #22 should be your crankcase vent hose Share this post Link to post Share on other sites
jeepwm69 7,751 Posted December 28, 2021 Not sure how I missed this one. On 12/24/2021 at 10:16 AM, Chevymec said: I have noticed recently that my 2005 Foreman 500 has started smoking. Not when cold or it has sat for a few days, but when I drive to the hunting stand and sits for a few hours. When I start it up it smokes pretty bad. Park it and the next rime I start it up no problem. I didn't notice this until I changed the oil and filter a few months a go. Napa gold filter( installed the right way) and Valvoline ATV 10w40. Usually in the auto world I would say this is a drain back issue and oil sitting in the head and leaking by the valve seals but it will do it after a cold start also also. The motor was rebuilt about 1000 miles ago with a Web cam and Big Bore kit. Head was checked and jug was bored. Do these have a crakecase hose or some type of pcv valve? I did check the oil and it was low. I have the short dipstick and added oil till it was at the middle of the 3 hash marks not screwed in. Couldn't find my manual to check to make sure this is correct , but I believe it is. Not sure how I missed this thread, but if it only smokes when recently ridden, I would agree with your assessment that it's oil leaking down through the valve seals. There is a crankcase vent hose that is on the left rear of the engine and goes to the airbox. Does it smoke under load? If you have a bad rod that's egging out the cylinder it should be wearing things to the point where it will smoke if you ride it hard at all. My 09 has a bad rod and it made noise for awhile, then started smoking under load. Doesn't smoke when cruising, only when I put a load on it in the mud or revving it up. Your symptom sounds more like a head issue to me. 1 Share this post Link to post Share on other sites
Chevymec 510 Posted January 1, 2022 On 12/28/2021 at 11:25 AM, jeepwm69 said: Not sure how I missed this one. Not sure how I missed this thread, but if it only smokes when recently ridden, I would agree with your assessment that it's oil leaking down through the valve seals. There is a crankcase vent hose that is on the left rear of the engine and goes to the airbox. Does it smoke under load? If you have a bad rod that's egging out the cylinder it should be wearing things to the point where it will smoke if you ride it hard at all. My 09 has a bad rod and it made noise for awhile, then started smoking under load. Doesn't smoke when cruising, only when I put a load on it in the mud or revving it up. Your symptom sounds more like a head issue to me. When it does smoke on start up. it does smoke under throttle. I don't really get on it hard a lot because I usually have one of my boys on it with me and he is holding the rifles. Today is the last day of hunting season so I will pull the rocker cover off here when I get a chance. Share this post Link to post Share on other sites
jeepwm69 7,751 Posted January 1, 2022 If it’s smokes under throttle your rod is probably shot and has egged out the cylinder Share this post Link to post Share on other sites
Chevymec 510 Posted January 9, 2022 While washing the Foreman today, I noticed that it does smoke when reving it up cold. So it looks like I might have to dig in deeper. Does anyone know what the actual size the BigBore kit was that High Lifter use to sell is? I emailed them today since my old login was no good. Does anyone else sell one or am I going to have to go back to a stock replacement piston and jug? Share this post Link to post Share on other sites
jeepwm69 7,751 Posted January 9, 2022 I don’t know of anyone else who made a big bore for the air cooled 500s. If I recall correctly the cylinder walls got a little thin and a lot of them had trouble with overheating I would see if HL offers anything and if not go back stock Share this post Link to post Share on other sites
Chevymec 510 Posted February 27, 2022 HL never answered back when I emailed them about the rings. I will probably just get a stock top end kit. We went riding the other day and my middle son told me it was hard to see me because it was smoking pretty bad. I guess I don't look back enough lol. Share this post Link to post Share on other sites
Chevymec 510 Posted February 27, 2022 Other than factory Honda parts, is there a preferred aftermarket brand top end kit? Just looking on eBay, there is about $300 difference in Aftermarket and Honda. Share this post Link to post Share on other sites
jeepwm69 7,751 Posted February 28, 2022 16 hours ago, Chevymec said: Other than factory Honda parts, is there a preferred aftermarket brand top end kit? Just looking on eBay, there is about $300 difference in Aftermarket and Honda. I use Shindy pistons. Made in Japan. I get them from biker chicks ltd on ebay. Guy's name is Grant Hawk. Share this post Link to post Share on other sites
