The 02 700 sportsman twin poofed some smoke and died this weekend – behaved like a head gasket from what I know. I could replace it, but it has made ticking noises for a couple years anyway.
I have never gotten very deep into engine work, and it is sort of on my bucket list to learn about it. Would this project/engine be worth it? Is it something I can figure out? I have normal “guy who does stuff” tools and a garage stall.
Building an engine isn’t hard, it having the patience to attend to every detail.
You’ll get a dozen different opinions and each will have their merits. Unfortunately the cost effectiveness of parts Vs a full or partial rebuilt can be challenging. I would research parts, availability, and cost vs availability and costs on rebuilt engine. That way you have a cap on your budget AND know that when you hit certain factors you’ll possibly switch gears.
Once you have a handle on that, tear down and inspection. Having a “tick” for a couple years would make me suspect excessive worn cylinder, bent piston, trashed crank. Obviously don’t know until torn down. If you find it’s worth a rebuild, go for it. If you find it’s trash, find a replacement
The early 700’s were known for head gasket, connecting rod/ crankshaft problems. That would be more of a “knock” than a “tick”. The ticking noise is possibly camshaft/valve related. If it made that sound for that long it may be a broken rocker or push rod. Or the camshaft may have broken. If it still turns over normally do a compression check on each cyl and go from there. It’s impossible to diagnose without seeing it first hand. This engine is not your typical Briggs 5 horse. There’s a lot more to know to just disassemble it let alone put it back together. And you will need more than your average handyman tool box for the job. I would highly recommend having someone experienced help you. But if you have the time and patience to study, you could do it. Good Luck
Best advise I can give is pull the head off. If it’s the top end needing work (usually is), fix it. If it’s the bottom end, you’re in for a lot more work and way more attention to detail. I would think long and hard about a bottom end rebuild on a 20 year old ATV. Been there, done that. Most likely wouldn’t do again.
Mechanic work is about the ability to diagnose correctly and accurately. IMO the first thing to do is stop guessing and get to work on the testing to figure out what REALLY went wrong. Assuming you know what’s wrong is a great way to spend lots of time and money fixing all the things that aren’t really the problem.
– Do a combustion gas test (using a test kit with gas-reacting dye) on the radiator to see if you are correct and it really is a blown head gasket. Of course, also check the oil for coolant contamination, smoke, etc if it’s totally obvious, but ultimately it’s the combustion gas test that is the gold standard to see if you have a head gasket leak.
– How’s the compression? Could you have lost a ring instead of a head gasket or is the top end just generally in bad shape? Do a compression test.
– I’d want to know more about that ticking noise and see if I could track it down more precisely. If you go forward with fixing it, I’d want to fix this as well, but again it all starts with knowing what’s wrong.
Then you can build a parts list and start to look at availability and options depending on what you need to do. There may be kits or other options, it all depends on what it needs. Also, depending on what’s wrong, watch YouTube videos to see what you’re getting into and determine if you think it’s within your skillset to do.
I DO NOT like working on ATVs because everything is so shoe-horned in, it’s like working on an ultra-compact car. It seems like Step 1 of every ATV repair is to spend 2 hours taking off plastics, shields, shrouds, harnesses, hoses, the covers to the covers, then the covers themselves, then… It’s a great way to hone your abilities to work in tight spaces, I’ll give it that. This is just my opinion so others will disagree and tell they’re the easiest thing to work on since the Model T, so do your own research.
Wow, looked up some options on crate motors and was quite surprised. Almost cheaper to drop in a ATK Chevy 350 crate motor than the sportsman 700 
Almost cheaper to drop in a ATK Chevy 350 crate motor than the sportsman 700
What was the average price you round for a reman, Randy?
As usual with ATVs, it’ll be more than a used running machine in excellent condition, so no way is it worth doing a built engine, I’d guess.
<div class=”d4p-bbt-quote-title”>Randy Wieland wrote:</div>
Almost cheaper to drop in a ATK Chevy 350 crate motor than the sportsman 700What was the average price you round for a reman, Randy?
As usual with ATVs, it’ll be more than a used running machine in excellent condition, so no way is it worth doing a built engine, I’d guess.
Just some quick google searches without looking at any specs ‘02-06 engine reman for the 700 is a little under 3k.
Basic reman Chevy 350 is about 3k
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That’s even worse than I thought. I’d think the current market value of a running 700 Sportsman would be 3000-3500 in good to very good condition.
Sorry Tindall, it’s going to be either fix whatever’s wrong or do a part out on that machine and try to get what you can back from it.
Let’s shoehorn a 350 into that thing. 
Let’s shoehorn a 350 into that thing.
A neighbor rebuilt his sxs and added a kit of nitrous . Giddy up!!!!
Factor in the chevy motor has carb and distributor. The motor ends up cheaper. I’d be careful putting a fresh top end on a 20-year-old lower end. Be like 60 year-old guy getting a 20-year-old girl friend. May be more than it can handle.
Some things in life r worth trying tho steve
Some things in life r worth trying tho steve
Speak for yourself Steve. Give me some nitrous er um. Giddy up! 
Be like 60 year-old guy getting a 20-year-old girl friend. May be more than it can handle.
Steven, I think that goes under the heading of, “But what a way to go.”
I’d be careful putting a fresh top end on a 20-year-old lower end. Be like 60 year-old guy getting a 20-year-old girl friend. May be more than it can handle.
Done it many times, once with your outcome lol. Honda TRX90, Rancher 350, 400EX, DS450, 2 Kawasaki 650/700’s. The one that failed was 100% my doing. Kawasaki 700 twin, 35HP 9.9:1, poked it to 730 and 12:1 with some radical timing, around 70HP. Made it another 1,500 miles before losing a bearing in the bottom end.
Can’t speak to Polaris bottom ends as much but they are known to be strong and far out last top ends.
Thanks everyone! This machine is my father in laws that he has essentially abandoned since he got his side by side, so it is probably going to just clog up my garage until I do something or toss it – I really don’t have much to lose trying and failing.
I agree that they are a pain in the ass to work on – changing the plugs involves snaking your hands in and loosening them one rachet click at a time, and needing a wrench on the socket for the other side. I can’t imagine I can even check the compression with the kit I have (hose to gauge) without removing a significant amount of parts above the engine (plastic, probably gas tank, etc.).
I will start with trying to get compression and go from there. I will have to google some of the other words grouse said to find out what they mean. I do have a connection and can typically get oem parts significantly discounted.
I’ll give you $200…. 
DT
That’s the DT engine. It was a good utility engine but not known to be a powerhouse. Not bad to rebuild, splitting the case isn’t a big deal and there are a lot of those engines out there so there are a lot of parts around.
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