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Discussion Starter · #1 ·
I just bought a 2001 325 trail boss and after two laps around my house, the fly wheel nut came off. I ran to ace and got another one that fit. Upon finding my problem, I noticed that the pull start mechanism is completely gone, and the gasket for the housing is too. Also there is a threaded hole next to the pull start sting that is wide open. This thing ran like a champ, when I test drove it and loaded it up, up until the nut came loose. It now sounds like there is a clanking in the top end, only at idle, and I don't have the same power. I noticed that I used the choke to start, and when running I can pull the choke in and out and nothing changes. I would think it would die when warmed up. Not sure if the choke is just stuck and giving the engine weird amount of air. Not sure if bolt getting caught up in fly wheel (it got smooshed) may have ceased flywheel enough to break something in the top end? but why would I only hear it at idle speed? Please help.....
 

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Welcome to the board!
 

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Have you done a compression test? Unfortunately it sounds like something let go internally when that bolt got lodged in there. To check the carb operation (choke, throttle, etc.) should be easy with a visual inspection.
 

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Welcome.

Sounds like someone had had it apart and did not put it back together completely.

I see used engines on eBay starting around $500. We bought a 325 with spun rod bearings so I been looking at our options.
 

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Discussion Starter · #5 ·
Compression is at 62, I found the range of 60-90 on line. Not sure how accurate that is. Now the damn thing wont start at all. I killed the battery, so I am charging it over night. So far I have checked the compression, checked the spark, and checked that it was getting fuel. All seem to be ok. I am curious if the fly wheel getting momentarily seized, by the nut that fell off, would it knock the timing off. Not even sure if atvs have timing. Anyone?
 

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The plate you rotate to change the timing is behind the flywheel so if the flywheel did seize I guess a lot of things could have happened.

To you have a place inside with a work table where you can tear the engine apart?
 

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Discussion Starter · #7 ·
I do have a shop, and I am ordering the service manual. Here's the thing, after the nut incident it still ran, but was under powered. I brought it in the shop and thought I would see if I could get to the carburetor. I just took off body parts and it won't run after that. So I am at a loss. I checked to see if i knocked anything lose and nope. The only thing i found, that i never touched, was under the head light. There are two wires, not hooked up to anything. One red one blue, and there is a plug with 2 yellow/ stripe wires that the other two can fit in. I know I didn't come close to these wires, so they were unhooked when it ran. Couldn't find wiring diagram after 3 hours of searching the net. I still want to check the carb, but want to order a gasket set before I start tearing it apart. Damn things are $65. And also finding out parts are hard to fin and very expensive. Right now I am thinking I should have just bought a Honda.
 

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Expect you are right on Honda when it comes to price/selection of parts.

We just put new connecting rod inserts and rings in our two. Compression should be more like 90 PSI.

We have found good used parts on eBay at great prices but be aware not all offers are priced the same. I have found better used parts for 1/2 the price of so so used parts listed.

They are easy to work on as long as you do not have to adjust air/fuel screw. :)

We found we were able to pull the connecting rod and replace the bear inserts without splitting the case by welding two sockets together pointed in opposite directions. The nut is 12mm. Use 3/8" drive max.

One of ours we bought knowing it had been ran out of oil due to the owner had not replaced the oil cooler lines soon enough. We may have to find a crankshaft for it if the new rod bearings fail due to the damaged crank shaft journal.
 

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Discussion Starter · #10 ·
ok, battery full charged, and I made sure the air box was closed properly and filter was on correct. Checked spark. Hooked up compression tester and after ten tests, 4 hit 150, 3 hit 82, 1 hit 90, and to hit 63. WTF????
 

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Discussion Starter · #12 ·
Thank you to everyone that posted. I solved my problem!!! I had fuel, Spark, and compression, so the only thing left was timing. My guessing that the flywheel nut fell off and jammed up the flywheel was correct. I took the flywheel off, and there is a locking pin/key on the crankshaft that aligns with a key hole on the flywheel. The nut jamming the flywheel, while the engine was running, caused it to blow out the lock pin/key and rotate to where it shouldn't be. Let me tell you how much fun it was to get the flywheel off, it sucked! I got it off, and rotated it back to normal position, put it together, and it fired right up. I imagine this will be a problem again since the pin/key was almost sheared off. I will probably have to grind a groove in the crankshaft and make my own key to keep it from moving. Seeing this is the first time I have ever worked on an ATV, and the shop service manual I so desperately needed isn't showing up for a few more days, I think i did alright. My kids were thrilled.
 

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Congtrats! So long as you've torqued the flywheel nut correctly, I'd be surprised if you have another problem with that again. My question is; without the recoil starter in place what's keeping pant legs, etc away from the spinning starter cup? I'd buy a recoil starter ASAP
 

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Discussion Starter · #14 ·
Ragdude, when my service manual arrives, I will double check the torque. I had to go with the old fashion hand torque technique for now. I do have a cover for the recoil starter, as it is needed to keep the starter gears in place and pant legs safe. The previous owner told me the cord broke off, not that the whole mechanism was missing inside. They are like a $139, so I will run with out it.
I wish I was more thorough with my inspection, when I was purchasing it last Saturday. I was pressed for time, my boys and I were too excited, and way too trusting of a stranger selling me something, which is not like me. Had I taken more time, I would have noticed all the bolts that are missing, all over the bike, which would have screamed-"somebody has been working on this bike and was not careful enough to keep track of bolts". That is the biggest trait of a half ass mechanic. I am an electrician, and problem solving is my life and passion. I don't know anything about ATV's, but have always bought used stuff and their service manuals, and I have been able to fix anything I bought-so far.lol. Everything I know about machines is because once upon a time I couldn't afford to pay someone to fix it and now I am too curious and stubborn and I don't want to pay someone. We stepped up from a 5occ to this 325, as my boys are growing. I am sure that by the time they get to middle school we will have a few complete engine rebuilds under our belts. I already have an itch to go buy another ATV down the street, that needs the top end rebuilt, just to learn how to do it, but the old lady will probably not be too happy. I already have a long "to do" list, so adding a fun project like that will not be received well. We have 3 boys and 1 ATV, so I am sure I will be on the next one soon. Thanks again for your help. I am sure I will be on this site many more times.
 

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Welcome Electroman. Glad you was able to get it fixed. Yep the flywheels are a pain in the .... Had a best bud when growing up that had a Honda mini trail50 that was riding without the cover for the flywheel...well lets say a person toe loses when it comes in contact of a spinning flywheel.
 

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Oh... gotcha
My first quad was an '01 - 325, still have the the '02 - 325, but the '01 was sold to get the '05. Great bikes, the '02 has been bullet proof with absolutely 0 problems, not even a recall so it has never seen the dealer since it left, same with the '01 while i had it. Yes I'm sure you'll have another soon haha ENJOY!
 
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