marcuswayne 21 Posted March 25, 2022 I just picked up a old 1986 Honda Fourtrax 350 4-wheeler. I just removed the motor to do a complete rebuild. This is what I found with the motor. When turning the motor over by a socket on the crank with the spark plug out and the valve covers off I see that the intake valves start to open just as the piston is getting to the top. This stops the piston and you can not turn the motor over. It looks like the timing chain has jumped and now the motor is not in time. What do you think made this happen? Is this a common thing with the 350's? After pulling the head off I see its in need of new parts. Top of connecting rod bad, cam looks worn, I think someone ran the thing low on oil. It looks like a great project. I hope that you all can help me with this project. Mark 3 Share this post Link to post Share on other sites
shadetree 5,969 Posted March 25, 2022 1 hour ago, marcuswayne said: I just picked up a old 1986 Honda Fourtrax 350 4-wheeler. I just removed the motor to do a complete rebuild. This is what I found with the motor. When turning the motor over by a socket on the crank with the spark plug out and the valve covers off I see that the intake valves start to open just as the piston is getting to the top. This stops the piston and you can not turn the motor over. It looks like the timing chain has jumped and now the motor is not in time. What do you think made this happen? Is this a common thing with the 350's? After pulling the head off I see its in need of new parts. Top of connecting rod bad, cam looks worn, I think someone ran the thing low on oil. It looks like a great project. I hope that you all can help me with this project. Mark welcome to our forum. you are deff in the right spot to help you fix that old girl. the only down side to her is locating used parts ? as new oem parts are mostly discontinued today, so this leaves you with china ? ( never use china on this atv ! ) or used parts, and pray you get some good used parts !?!. with it being 30 something yrs old ?, chances are, the cam chain stretched too far, and jumped time. as for the lack of oil ?, oil filter in backwards ?, dont laugh...we see it all the time !. be sure to check those valves to see if they got bent by the piston ?, if they are bent ?, you prob wont find new oem valves anywhere ?, but good luck if ya do !. these model atvs are tanks...last longer than you will live ?!..but unless you fail to locate parts for them ?, its a paper weight ..sad...but true..as those atvs are some of the best atvs honda ever built and sold. with that being an '86 model ?, IT IS A ONE YEAR PARTS ONLY !!.. a few parts ( not many ! ) will swap over from '89 models..but for the most part..all parts electronic wise MUST BE FOR A 1986 TRX350 fourtrax...you can not use any models after '86 on that atv. some engine parts..yes..not many though. 2 Share this post Link to post Share on other sites
_Wilson_™ 6,591 Posted March 25, 2022 Welcome to ATVH. Share this post Link to post Share on other sites
Fishfiles 20,147 Posted March 25, 2022 Welcome to the forum !! ---- Share this post Link to post Share on other sites
marcuswayne 21 Posted March 25, 2022 Thank you for the info. I'm still going over parts and cleaning them up. This is my first Wheeler and it looks to be in good shape just the motor looks like it's got some miles on it. I like a challenge and this is going to be interesting. One thing I am looking for is a service manual for this 350 motor. Is there one service manual you would recommend? Thanks again Share this post Link to post Share on other sites
Fishfiles 20,147 Posted March 25, 2022 See if you like this one 86-89 350 https://drive.google.com/drive/folders/1hRCn9_Bcu8HgyrMDc3YcyX0EtzSgzE0b You got a better pic of your vehicle in your aviator ? Share this post Link to post Share on other sites
marcuswayne 21 Posted March 25, 2022 That pic. in my aviator is of a haul truck that I built year ago. Its 4-wheel drive, hydraulic dump, 27hp Kohler twin cylinder, hydrostatic drive. It's used to haul my fire wood or what ever. 3 Share this post Link to post Share on other sites
Fishfiles 20,147 Posted March 25, 2022 Wow , that is so cool , so is your tractor and splitter !! Share this post Link to post Share on other sites
jeepwm69 7,719 Posted March 25, 2022 Welcome aboard. We like the old 350's here and we also like talking chainsaws/wood/other neat guy stuff as well. You can send your crankshaft to Vince at Mr Crankshaft for a new connecting rod. He uses Vesrah which are excellent quality. Some parts for the old Foremans are not easy to find, but overall parts for them are usually cheap as most people don't go to the trouble of fixing them up. Mufflers, rear ends, good plastics, and cylinder heads are usually pricey. The rest of them can be had relatively cheap when compared to other ATV's. 2 Share this post Link to post Share on other sites
THH 297 Posted March 25, 2022 Welcome marcuswayne, That is one cool wood hauler for sure, good luck with the 350. 1 Share this post Link to post Share on other sites
_Wilson_™ 6,591 Posted March 25, 2022 that's a very nice setup, we have a few threads here on chainsaws (everything chainsaws) (firewood burners) (let's talk farm equipment) page two under general chat. 1 Share this post Link to post Share on other sites
Chevymec 510 Posted March 28, 2022 Welcome to the site!! Share this post Link to post Share on other sites
marcuswayne 21 Posted March 31, 2022 I have a question The 86 fourtrax 350 that I picked up that someone ran out of oil or very low, looking over the motor I think it would be better to find another motor. Is the Foreman 350 motor the same as what I have is a Fourtrax 350???? Share this post Link to post Share on other sites
Goober 1,555 Posted March 31, 2022 You mean the cam, gear, chain and valves? because the engines have many differences. For instance the stators are not. use the oem parts finder at Rocky Mountain atv or Partzilla. Cross reference the part numbers. Share this post Link to post Share on other sites
Goober 1,555 Posted March 31, 2022 Here’s link https://www.rockymountainatvmc.com/oem-parts?PID=6162047&ref=cj&cjevent=739b5cf1059a11e983e401da0a240614 Share this post Link to post Share on other sites
marcuswayne 21 Posted March 31, 2022 I was thinking of changing the motor out with a motor off a foreman and wanted to know if it would fit? I have only taken the top of my 350 and what I see is not good, connecting rod not good, cam looks bad, I'm sure timing chain is bad. The timing chain sprocket on the cam looks good. Where the cam runs in the head not looking good. I feel that this would be a good parts motor. I have found some motors around just trying to figure out my best option. Share this post Link to post Share on other sites
marcuswayne 21 Posted March 31, 2022 I ordered parts for the frontend at Chaparral and after a week they sent an e-mail telling me the 6 items that I ordered they did not have. Great. I then ordered the parts from Partzilla and now just watching the mail. Finding parts is a challenge, but making new parts is part of the fun. Share this post Link to post Share on other sites
jeepwm69 7,719 Posted March 31, 2022 1 hour ago, marcuswayne said: I ordered parts for the frontend at Chaparral and after a week they sent an e-mail telling me the 6 items that I ordered they did not have. Great. I then ordered the parts from Partzilla and now just watching the mail. Finding parts is a challenge, but making new parts is part of the fun. Rocky Mountain ATV and Honda East Toledo are usually your cheapest place for OEM parts. partzilla has the best schematic layout for when you’re finding what you need to order. 2 Share this post Link to post Share on other sites
shadetree 5,969 Posted March 31, 2022 2 hours ago, marcuswayne said: I ordered parts for the frontend at Chaparral and after a week they sent an e-mail telling me the 6 items that I ordered they did not have. Great. I then ordered the parts from Partzilla and now just watching the mail. Finding parts is a challenge, but making new parts is part of the fun. i hate to rain on your parade ?, but you are going to find out from partzilla, and anyone else you ordered parts from ?, most parts for this atv are discontinued, you can not buy new parts from honda for it. its all used parts for most of the parts on it. yes, the later model engines will fit in the frame, BUT !!..1986 is a one-year only engine, in other words..it has to have all 1986 trx350 electronics, where the later yrs will swap out on some of the parts. if you drop ,say a 1989 trx350D motor in the frame ?, you will need the wire harness, as well as all the elec parts to go with it..you simply can not just swap engines..it will not work !. 1 Share this post Link to post Share on other sites
marcuswayne 21 Posted March 31, 2022 Thanks for the info, this is going to be one of those projects. In the end I think this old crusty and neglected wheeler is worth it. This old wheeler will roll. Share this post Link to post Share on other sites
Goober 1,555 Posted March 31, 2022 (edited) Fleabay is a great source for NOS items like pistons and valves, but you can go quite a long while looking for a cam. might be able to buy a decent used head and cam, maybe even an engine. the other members here are a lot more knowledgeable on this however i can tell you the 86 model TRX350A is different in many ways to other models including the 87 TRX350A and 87 TRX350D. i would shop specifically for a 86 engine or parts. for starters. TRX350A uses a different stator so you would have to swap yours to a D engine. After 87 the D models have a different compression release mechanism so swap that also if it will work. the manual shows the cam lobes after 86 are different, which may mean the heads might be different. 2000 and later transverse mounted TRX350 engines would not fit frame or drivetrain or electrical without significant mod. So when you mentioned other TRX350 I would rule them out. Edited March 31, 2022 by Goober Share this post Link to post Share on other sites
marcuswayne 21 Posted April 9, 2022 Picked up another 86 honda 350 fourtrax that I'm hoping the motor is good. The guy I bought the wheeler from said he stoped riding it because it smoked. Been siting in his barn for some time. Motor turned over ok. My plan is to pull the motor off and pull the head and hopefully it will only need the top end done. Hopefully. Pressure washed the old wheeler down, just to clean it up before I pull the motor. The old wheeler will also give me lots of spare parts. 3 Share this post Link to post Share on other sites
shadetree 5,969 Posted April 10, 2022 21 hours ago, marcuswayne said: Picked up another 86 honda 350 fourtrax that I'm hoping the motor is good. The guy I bought the wheeler from said he stoped riding it because it smoked. Been siting in his barn for some time. Motor turned over ok. My plan is to pull the motor off and pull the head and hopefully it will only need the top end done. Hopefully. Pressure washed the old wheeler down, just to clean it up before I pull the motor. The old wheeler will also give me lots of spare parts. in case you do not know ?, the atc350x uses the same head as these models !. 1 Share this post Link to post Share on other sites
marcuswayne 21 Posted April 14, 2022 Thanks Shadetree Hope to get back to work on the wheeler in a couple weeks. Share this post Link to post Share on other sites
Stateboy 11 Posted April 16, 2022 Greetings from Northern Michigan. I just picked up a white 2017 Honda Foreman 500 (TRX500fe2) with 500 miles. Its my first ATV and this one is all stock. I live near lots of state land that I'm looking forward to explore. I'll be seeking an owners and service manuals since neither came with the ATV. 2 Share this post Link to post Share on other sites