Dimebag
TY 4 Stroke God
It seems like my season ended today,
After having enjoyed the spring snow on full throttle all day, blew a belt,had a couple rollovers, and finally while going at WOT up a hill i got a clattering/ knocking sound coming from the engine.
I let off the throttle as soon as the noise appeared. (resulting in another roll-over..)
Fired her up again, got the low oil pressure code, and engine stopped again. Checked the oil level, which seemed to be good.
Fired her up once more, idled fine .. everything seems ok. I give it some throttle and the knocking returns again.
After some arguing we decided it was best to not start the engine again, and instead tow it back home.
I was towed home by a Polaris.
Sled is a 2008 MCX 180 with 12000 KMs on it.
What is the problem here guys?
After having enjoyed the spring snow on full throttle all day, blew a belt,had a couple rollovers, and finally while going at WOT up a hill i got a clattering/ knocking sound coming from the engine.
I let off the throttle as soon as the noise appeared. (resulting in another roll-over..)
Fired her up again, got the low oil pressure code, and engine stopped again. Checked the oil level, which seemed to be good.
Fired her up once more, idled fine .. everything seems ok. I give it some throttle and the knocking returns again.
After some arguing we decided it was best to not start the engine again, and instead tow it back home.
I was towed home by a Polaris.
Sled is a 2008 MCX 180 with 12000 KMs on it.
What is the problem here guys?
judger101
Expert
thats too bad!
Did you end up putting a manual boost controller on it? If so, how much boost @ what altitude?
Bummer None the less!
Bummer None the less!
Btw, that's a lot of miles! Good work on logging that many miles!
Dimebag
TY 4 Stroke God
rlcofmn said:Did you end up putting a manual boost controller on it? If so, how much boost @ what altitude?
Bummer None the less!
I have used a manual boost controller since late feb, running 7.5 psi @ 4500 ft today.
Mtnviper
Vendor
Thats to bad Dime, its never a good thing to hear them knock.
You were wise not to start it, if she's got bottom end damage (rod bearings/crank) it can be repaired in most cases.
By trying to ride it out, there is a really good chance it would have pitched a rod through the block and then your looking at a complete engine.
When you go to tear it down, if you find spun rod bearings. Be sure to pull the valves out and check them for straightness. What can happen if a rod bearing spins, the extra clearance can allow the piston to travel farther up the bore and just kiss the valves. The valves are small and won't always leave witness marks on the pistons so the best way to check them is to chuck them up in a lathe.
If the valves are slightly bent, they will hang up (stick open) at higher rpms, then the piston smacks the valve head a few times. Which causes the valve head to break off and lunch the motor.
Bill
You were wise not to start it, if she's got bottom end damage (rod bearings/crank) it can be repaired in most cases.
By trying to ride it out, there is a really good chance it would have pitched a rod through the block and then your looking at a complete engine.
When you go to tear it down, if you find spun rod bearings. Be sure to pull the valves out and check them for straightness. What can happen if a rod bearing spins, the extra clearance can allow the piston to travel farther up the bore and just kiss the valves. The valves are small and won't always leave witness marks on the pistons so the best way to check them is to chuck them up in a lathe.
If the valves are slightly bent, they will hang up (stick open) at higher rpms, then the piston smacks the valve head a few times. Which causes the valve head to break off and lunch the motor.
Bill
Dimebag
TY 4 Stroke God
So we are more then likely talking about a rod bearing failure? Which would mean I also need a new crank?
Mtnviper
Vendor
Yeah, the rod bearings are the first to go when there is an oil pressure loss. When the bearings are damaged it will damage the crank as well.
If a rod bearing is spun, it will need the effected connecting rod also.
Since your already boosted and you end up having to tear the engine down, it might not be a bad time to upgrade to aftermarket rods and pistons for a little more boost!
You can test the oil pressure using a mechanical oil pressure gauge. About half way down the page in the link below shows how to test it.
http://www.ty4stroke.com/viewtopic.php? ... highlight=
If a rod bearing is spun, it will need the effected connecting rod also.
Since your already boosted and you end up having to tear the engine down, it might not be a bad time to upgrade to aftermarket rods and pistons for a little more boost!
You can test the oil pressure using a mechanical oil pressure gauge. About half way down the page in the link below shows how to test it.
http://www.ty4stroke.com/viewtopic.php? ... highlight=
00-NUKE
Expert
Mtnviper said:Yeah, the rod bearings are the first to go when there is an oil pressure loss. When the bearings are damaged it will damage the crank as well.
If a rod bearing is spun, it will need the effected connecting rod also.
Since your already boosted and you end up having to tear the engine down, it might not be a bad time to upgrade to aftermarket rods and pistons for a little more boost!
You can test the oil pressure using a mechanical oil pressure gauge. About half way down the page in the link below shows how to test it.
http://www.ty4stroke.com/viewtopic.php? ... highlight=
X2
My 2008 burned up after a acquired some damage to my oversized oil filter form an impact. It started out sounding like something ticking in my primary clutch. Before I knew it, I had a baseball sized hole in the bottom of my engine. Be glad you caught it when you did! A crank and rods is dirt cheap compared to what Yamaha gets for a Nytro engine.
Dimebag
TY 4 Stroke God
We will open up the engine next week or something to look at the damages.
Carillo rods and JE pistons, is that the way to go? What about valves?
Anything else i should consider upgrading while Im at it?
Carillo rods and JE pistons, is that the way to go? What about valves?
Anything else i should consider upgrading while Im at it?
Mtnviper
Vendor
Dimebag said:
I think so. However I would check with MCX to see what they recommend to be sure. Since the head bolts are non-reuseable, you may want to look into a head stud kit.
OEM valves (if required) should be fine.
sorenson1610
TY 4 Stroke God
- Joined
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That sucks dime but the plus side is you get to add some fun stuff to your motor! Glad you didn't punch a hole in the side of the block too. Let us know what you find when you rip it apart
Dimebag
TY 4 Stroke God
I will talk to Marklund at MCX after we know for sure what the damages are.
Anyone got any good setups (rods/pistons) to recommend, please let me know.
Ill keep you posted.
Anyone got any good setups (rods/pistons) to recommend, please let me know.
Ill keep you posted.
Knock knock who's there ?
----->
It`s me, Rod bearing failure (crushing the crank at the same time).
----->
It`s me, Rod bearing failure (crushing the crank at the same time).
nytro-king
Extreme
seems to me that the 180 kit is no good to the nytro engine. 
