Seized Engine

[PearlWhiteGT]

Thanks fellas, will report back in a few days.

 

[jjeff]

Thanks fellas, will report back in a few days.

One more thing the 350, 400, and 450 Yamaha ATVs have a lot of compression and are very hard to start using the pull chord, cold especially, locked up engine or not lol. Yamaha didn't or doesn't even put pull chords on the bigger bore ATVs but have a decompression valve. Good luck with this project. Personally free stuff involving motors are my favorite projects.

 

[jjeff]

Thinking back when I owned a 450 Kodiak the float needle wouldn't seat properly I thought my engine was seized, nope it was hydrolocked with a gallon+ of gas.

 

[Hoss710]

The petcock on the yamahas have a fine screen in them that get gunked up pretty bad. I see them cheap on ebay. figured it was worth mentioning. also replacement carbs are cheap on there as well. I just did both on my 04 660 grizzly.

 

[ruffdog]

I would have pulled the clutch cover off instead. Normally, not much to lock it up on the stator side. Instead of the piston seized, a dropped valve or broken cam chain can lock it up. You will have to pull the cam cover before the head and at that point you can inspect the valve action and chain.

 

[PearlWhiteGT]

The petcock on the yamahas have a fine screen in them that get gunked up pretty bad. I see them cheap on ebay. figured it was worth mentioning. also replacement carbs are cheap on there as well. I just did both on my 04 660 grizzly.

What brand of carb did you go with? Seens different ones on there.

 

[Hoss710]

What brand of carb did you go with? Seens different ones on there.

Oddly I looked up what I had bought, and it doesn't list a manufacturer. haven't had any issues with it so far. and a ton cheaper than the OEM part.

 

[PearlWhiteGT]

Well I found some bad stuff when I drained the oil today. All this came out.

 

[Eagle1]

Top end time.... and check the bottom end as well. It can still be a good machine. Personally I'd pull the motor so much easier to work on a bench than in the frame. I am surprised that piece of ring came out during an oil change. If you can do your own work it is not real expensive but if you pay a shop.......
Note many of these machines have an internal screen to catch chunks, some you see and can clean without splitting the bottom case but some like the Brute Force 750 require you to split to even know it's there.

 

[PearlWhiteGT]

Yeah this one has the screen. Most of the small pieces came out before removing the screen. With the screen removed to reached my finger in and found the piece of ring. Not sure what I plan on doing with it.

 

[grsthegreat]

It might end up looking like this engine

 

[PearlWhiteGT]

I thought about buying one of those cheap cylinder/piston kits from amazon or eBay but I feel like it will just lead me down the rabbit hole and will end up spending more money and time on it. If I needed the machine it would be a no brainer for me to repair it but I'm leaning towards putting it up for sale as is and let them know everything that I know. I could always use the extra beer money.

 

[LD1]

No harm in pulling it apart and seeing what it needs ....and if nothing more to appease the curiosity of just what failed and why. For me, I could never sell or part with it without knowing just what went wrong....

 

[PearlWhiteGT]

No harm in pulling it apart and seeing what it needs ....and if nothing more to appease the curiosity of just what failed and why. For me, I could never sell or part with it without knowing just what went wrong....

I totaly get this and feel the same but my main issue is time and space for the machine. At the moment I have the garage space but that's only due to my car being in the body shop. Once I get it back I have nowhere to keep the machine where I can work on it.

 

[5030]

Do you have a borescope available to do a peek down the lightening hole?

An endoscope on Amazon or Flea Bay is cheap. They jack into your cell phone and provide a look-see inside for around 15 bucks.

if it was my project, I'd put some acetone-ATF in the jug and then slowly rock the crank back and forth until it broke free. Just how I'd approach it.

 

[jjeff]

An endoscope on Amazon or Flea Bay is cheap. They jack into your cell phone and provide a look-see inside for around 15 bucks.

if it was my project, I'd put some acetone-ATF in the jug and then slowly rock the crank back and forth until it broke free. Just how I'd approach it.

Imo the engines condition is well beyond the acetone and ATF stage to free. Lol. I had no idea until this post a "rebuilt" replacement long block is 2k+

 

[PearlWhiteGT]

An endoscope on Amazon or Flea Bay is cheap. They jack into your cell phone and provide a look-see inside for around 15 bucks.

if it was my project, I'd put some acetone-ATF in the jug and then slowly rock the crank back and forth until it broke free. Just how I'd approach it.

I got it broken free already a couple of days ago. Only thing that will fix it now is pretty much a engine rebuild at worst or piston/jug kit at best.

 

[PearlWhiteGT]

Imo the engines condition is well beyond the acetone and ATF stage to free. Lol. I had no idea until this post a "rebuilt" replacement long block is 2k+

Yup and I don't think the machine is worth that much once it's up and running.

 

[jjeff]

Yup and I don't think the machine is worth that much once it's up and running.

If it was mine I problaby wouldnt stop at the engine but end up rebuilding the CVT drive system or at least a new drive belt and keep going from there, If that 400 had independent rear suspension it would be more desirable imo.
It was free however? what's the miles on it?

 

[PearlWhiteGT]

If it was mine I problaby wouldnt stop at the engine but end up rebuilding the CVT drive system or at least a new drive belt and keep going from there, If that 400 had independent rear suspension it would be more desirable imo.
It was free however? what's the miles on it?

Shows right over 1000 but I believe it can be reset with the dial on the side of the odometer.