I have a 03 Sportsman 700 that has a little play up and down and side to side in the piston rods. 3 of 4 lifters are concave at the bottom. The cylinder walls and pistons look fine to me. All nice and smooth but I am by far an expert. My best guess is I need a new crankshaft , camshaft and lifters. Question ( 1 ) I have no experience doing this type of work. But I do have the service manual. Am I stupid for even attempting to do this? (2) What else would I need? Is there a gasket kit involved? Should the balance shaft be replaced also? (3) Is it worth trying to track down a used crankshaft ? They are so darn expensive new. (4) If I gave up this idea and take the motor to a qualified mechanic what do you think I would be looking at in a rebuild bill? Money is kind of tight here.Your advice is really appreciated.

 

Get a manual first off to see what all is involved!!! Hard to find a place to rebuild a crank.. usually have to get a new one or re manufactured one. Cam shaft if OK can be reused,same for lifters. Plenty of things to check on this engine,plus you might check into complete engines with your core for exchange..

 

I have the service manual. It looks complicated that's why I am questioning doing it myself. Complete engine is just shy of $3000 Called Atv repair guy machine shop by me. Said minimum around $2000 to rebuild engine. I don't have that kind of money at this moment. Would I be better off buying a new one (which means 3-4 yr loan) and parting this one out on ebay? Is it worth the risk to try and tackle this job myself? I can get the crankshaft re-manufactured ( i believe it is) for around $600 I am thinking I can get this done if I do myself for under $1000. Is this wort it? It is a 2003 after all. Most everything else I replaced. All CV axles ball joints stator upgrade. Brand New Tires etc etc

 

You've already upgraded quite a bit with suspension,axles,tires and ignition. In my opinion if you take your time,have found a place to rebuild the crank,you'd have a good machine that hopefuly will last a good many more years. Just take it one step at a time on engine rebuilds.. I learned a long time a go don't look too far ahead or it will frustrate you,just finish one step at a time,then go to the next one.Won't be long that the engine will be done and that you'll know what's in it because you did it your self! Not a better feeling than that.. I felt the same thing after every rebuild I did.Plus better than going into debt on a new one that will drop in value when it leaves the lot!

 

you could watch for a good used engine on ebay.I did a search there and found some good 400s and 500s for around a grand.Of course maybe a 700 is a lot more i don't know that.at any rate engines new or rebuilt do seem expensive for these machines.

 

I watched a few videos on motor rebuilds also read over and over the service manual. I think I can handle it if I pay attention and take my time. I already have the motor out and it is on my bench. Wish me luck!

 

jgiljr, If you do the work yourself, just pay close attention to how you take everything apart. As for question 2, in order to change the crankshaft you have to take the motor completely apart. So since you already have it apart you might as well change all the gaskets. Ebay has quite a bit of complete gasket sets and they work perfectly and are a little over $100. Answer to question 3, sometimes you will make out great with a used crankshaft and sometimes you're better off spending $$ for the new one. Personal preference. Answer to question 4, if you feel confident that you could do the repairs yourself, you could save yourself some money that way. If you decide to have a mechanic do it, I would call around and get price quotes from more than just one place. I'm currently working on two quads that I'm rebuilding the engines and they both are under $1000. If you have any other questions or problems I'd be happy to help ya out.

 

Thanks I am taking pictures of everything I take apart and think I will not remember how it goes back. Also placing all bolts back in respective areas and color coded all electrical wires. This way I am not trying to sort out what is what. A little extra work, but should save me a lot of grief in the long run. I plan on getting everything new and will definitely change all the gaskets. If I am going to do this I want to make sure I can get some years out of it. Only part that is killing me is the crankshaft. The re-manufactured one fell through. Best price I got so far new is $721.00 The Hotcam guy that is supposed to be so cheap , everyone talks about wants $100 more! I am learning a lot already. Made my own primary clutch puller. Which worked well Tried everywhere to buy 3/4 -16 threaded rod but none within 100 miles. Rummaged through my Junk box and found a bolt about 3 1/2 inches long that fit. I took an old broken 3/8 drive extension about 6 in long I had laying around and cut socket end off down about 2 in. Which made about a 4 in piece. shoved that in tightened the other bolt and she popped right off. The Secondary clutch came of easy by hand. I will be digging into the motor tomorrow and see all in all what else I will be needing.

 

When you get to pulling the gears behind the stator pay close attention to the double spring loaded gear on the cam. Install a dowel or punch in one of the holes before you remove it and set this gear assembly in a safe place.Can save some headaches when comes time for reassembly if you don't let the springs slip. Plus on torquing the gear bolts back on you don't have to have the gear holder tool. A good old penny locked between the crank gear will work fine as a gear lock. Don't think Uncle Sam will mind..

 

Great advice Thank you!