2015 Husqvarna TC250 top end

gameover
Profile picture for user gameover
Posts
59
Joined
4/8/2015
Location
Fort Walton Beach, FL US
gameover
Edited Date/Time 3/15/2016 12:38pm
Hi guys!

So I have lost compression on my stock bike with only 26hrs on it. I'd like to find exactly where the leak is because I can hear air leaking out of somewhere when I kick start it with my hand (yes I can actually turn the motor with my hand). However, if chasing the leak will be harder than just doing a top end rebuild then I'm down for that. Screw it.

The question is:
1. Should I get a wiseco or a vertex piston?
2. Should I just get a 300 kit instead?

Thanks a lot!
|
sostoked
Profile picture for user sostoked
Posts
247
Joined
3/26/2015
Location
Twentynine Palms, CA US
sostoked 2/21/2016 10:01pm
2/21/2016 10:01pm
what happened? bike shouldnt let go at 26 hours...
gameover
Profile picture for user gameover
Posts
59
Joined
4/8/2015
Location
Fort Walton Beach, FL US
gameover 2/22/2016 5:41am
2/22/2016 5:41am
I used the bike on the track, washed it with my pressure washer at home, and when time came to start it up I noticed how soft the kick starter was and could not get the bike to start. Dried up the bike with a cloth and let it be. A couple days later I started it up with no issues (at this point the kick start was not soft. It had compression).

Drove the bike to the track went around a couple of laps with no issues when all of a sudden going up a a hill the bike dies acting like it had ran out of gas. Tried kick starting it and there was no compression. Called it a day as I couldn't start the bike again.

It seems like compression comes and goes! Sad

Spark plug has never been replaced.
KTMShane699
Profile picture for user KTMShane699
Posts
1307
Joined
12/6/2013
Location
Colchester, CT US
KTMShane699 2/22/2016 7:04am
2/22/2016 7:04am
I'd go with a vertex over a wiseco, but either would work fine for your application. As for the cause, the fact that compression comes and goes make it very strange. I'd take the top end off and maybe toss a new ring in it. A ring won't cost much and you'll replace all of the gaskets to ensure they're not the problem.

rallendude
Profile picture for user rallendude
Posts
2200
Joined
8/17/2006
Location
Adger, AL US
rallendude 2/22/2016 7:42am
2/22/2016 7:42am
26 hours is way to early to be having issues on a TC250. Have you checked the spark plug to see if it's backed out?

The Shop

See All »
xnationalwrench 2/22/2016 6:49pm
2/22/2016 6:49pm
It sounds like you have injested dirt into the engine possibly thru the air filter. I have never heard of compression coming and going what does the spark plug look like? If you don't want to tear down the top end yet remove the exhaust and with a flashlight turn the bike over and see if you can find a problem that way.
gameover
Profile picture for user gameover
Posts
59
Joined
4/8/2015
Location
Fort Walton Beach, FL US
gameover 2/27/2016 9:13am
2/27/2016 9:13am
So I went with the vertex piston.

Tore the top end apart and here's what I found:

My gut feeling is that I need a new head too...?








gameover
Profile picture for user gameover
Posts
59
Joined
4/8/2015
Location
Fort Walton Beach, FL US
gameover 2/27/2016 5:46pm
2/27/2016 5:46pm
Bike stalled on the face of a jump. Lost compression and wouldn't start. Perhaps, dirt came theough the carb or pushed in through the exhaust port during power washes Sad

Now am faced with the dilemma of fixing this or just getting the 300cc kit from husky.
slipdog
Profile picture for user slipdog
Posts
10044
Joined
7/25/2009
Location
Nor Cal, CA US
slipdog 2/27/2016 7:49pm
2/27/2016 7:49pm
gameover wrote:
Bike stalled on the face of a jump. Lost compression and wouldn't start. Perhaps, dirt came theough the carb or pushed in through the exhaust port...
Bike stalled on the face of a jump. Lost compression and wouldn't start. Perhaps, dirt came theough the carb or pushed in through the exhaust port during power washes Sad

Now am faced with the dilemma of fixing this or just getting the 300cc kit from husky.
That's not from dirt, only metal will tear up a piston and cylinder with deep groves like that. You need to find out what got loose in your motor.
Crush
Profile picture for user Crush
Posts
20962
Joined
4/26/2009
Location
Sydney AU
Crush 2/27/2016 7:57pm
2/27/2016 7:57pm
Agree with Slip. 26 hrs and something like that, i'd be back to the dealer!
oldandslow1
Profile picture for user oldandslow1
Posts
174
Joined
2/14/2016
Location
Pinconning, MI US
oldandslow1 2/28/2016 5:58am
2/28/2016 5:58am
for sure not dirt, i would have a really good look around. your missing a part from the engine someplace. any play in the crank?
Slosh 112
Profile picture for user Slosh 112
Posts
1155
Joined
3/31/2014
Location
Mackay QLD AU
Slosh 112 2/28/2016 11:43am
2/28/2016 11:43am
It almost looks like it just got really hot and the metal blew out in those two grooves, to me it doesn't look like gouging from some metal in there. I think it looks like the cylinder lining has failed and the heat blew out the cylinder.
gameover
Profile picture for user gameover
Posts
59
Joined
4/8/2015
Location
Fort Walton Beach, FL US
gameover 3/3/2016 7:38am
3/3/2016 7:38am Edited Date/Time 3/3/2016 7:39am
Slosh 112 wrote:
It almost looks like it just got really hot and the metal blew out in those two grooves, to me it doesn't look like gouging from...
It almost looks like it just got really hot and the metal blew out in those two grooves, to me it doesn't look like gouging from some metal in there. I think it looks like the cylinder lining has failed and the heat blew out the cylinder.
I think you're right on target. Look at the piston rings: half of the top ring is missing!



Motojeff
Profile picture for user Motojeff
Posts
7
Joined
2/26/2016
Location
Gresham, OR US
Motojeff 3/3/2016 10:56am
3/3/2016 10:56am
That was caused by a normal "leaned out" condition likely caused by something like an air leak, it just made a really interesting scar like that because of the way the ring broke, and ran down the cylinder in 2 pieces.

The head looks fine, that bit around the spark plug just looks like the way the casting was done.

Good choice on the vertex they where, and may still be the company making the OEM pistons for Husky, Berg, and KTM. Your not going to miss out on much by sticking with a 250cc vs the 300cc, besides a bigger dent in the wallet.

DTHA70
Profile picture for user DTHA70
Posts
336
Joined
9/25/2008
Location
Surprise, AZ US
DTHA70 3/3/2016 11:15am
3/3/2016 11:15am
you also need to make sure that parts of the ring don't go down into the crank case.

looks like it was running a bit on the lean side just looking at the piston and head(there should be LITTLE bit of carbon on them)

If it were mine it'd be getting torn completely down for a bottom-up rebuild and some porting.
Hondas4Life3
Profile picture for user Hondas4Life3
Posts
854
Joined
7/30/2013
Location
Louisburg, KS US
Hondas4Life3 3/3/2016 2:20pm
3/3/2016 2:20pm Edited Date/Time 3/3/2016 2:21pm
DTHA70 wrote:
you also need to make sure that parts of the ring don't go down into the crank case. looks like it was running a bit on...
you also need to make sure that parts of the ring don't go down into the crank case.

looks like it was running a bit on the lean side just looking at the piston and head(there should be LITTLE bit of carbon on them)

If it were mine it'd be getting torn completely down for a bottom-up rebuild and some porting.
I agree there is no way to know if there are still bits of the ring in the bottom end unless you take it all apart. The crank at 25 hours is probably fine so new crank bearings/seals is probably all thats needed for the bottom.

Buy a leak down tester.
gameover
Profile picture for user gameover
Posts
59
Joined
4/8/2015
Location
Fort Walton Beach, FL US
gameover 3/3/2016 2:24pm
3/3/2016 2:24pm
DTHA70 wrote:
you also need to make sure that parts of the ring don't go down into the crank case. looks like it was running a bit on...
you also need to make sure that parts of the ring don't go down into the crank case.

looks like it was running a bit on the lean side just looking at the piston and head(there should be LITTLE bit of carbon on them)

If it were mine it'd be getting torn completely down for a bottom-up rebuild and some porting.
Hondas4Life3 wrote:
I agree there is no way to know if there are still bits of the ring in the bottom end unless you take it all apart...
I agree there is no way to know if there are still bits of the ring in the bottom end unless you take it all apart. The crank at 25 hours is probably fine so new crank bearings/seals is probably all thats needed for the bottom.

Buy a leak down tester.
....I'm beggining to think that the motor might have to come off too.

I just sent the head to Eric Gorr and it would suck if pieces of the rings screw everything again.

Pit Row

See All »
YZed250
Profile picture for user YZed250
Posts
1051
Joined
11/9/2014
Location
Costa Mesa, CA US
YZed250 3/4/2016 8:50am
3/4/2016 8:50am Edited Date/Time 3/4/2016 8:52am
Show the pictures to Eric Gorr as he will have a pretty good idea as to why your ring snagged the port. I'm guessing you had too little fuel or no premix oil.
Splitting the cases to find the piece of broken ring is not that difficult, but can be time consuming. I just split my KTM 250 for a crank rebuild.
If it were me, I would check the crank case for a piece of broken ring, but I'd bet that the shrapnel was sent into the exhaust and you don't have to worry about it.
Inspect your powervalve where it meets the cylinder as it might be scarred from the ring letting loose. This would need to be fixed before you put the bike back together. I have a used powervale for sale ($80) if you need one. KTM/Husky call it a control flap.

When ordering your cylinder base gasket, measure the thickness of your old gasket and order the same one from KTM/Husky. Alternatively, if you order a topend gasket kit through Moose, it comes with a 0.3, 0.5 and a 0.8 mm thickness gasket. This will enable you to set the cylinder height so that the edge of the piston is flush. KTM refer to this as setting the X-dimension to zero.


YZed250
Profile picture for user YZed250
Posts
1051
Joined
11/9/2014
Location
Costa Mesa, CA US
YZed250 3/15/2016 12:38pm
3/15/2016 12:38pm
DTHA70 wrote:
you also need to make sure that parts of the ring don't go down into the crank case. looks like it was running a bit on...
you also need to make sure that parts of the ring don't go down into the crank case.

looks like it was running a bit on the lean side just looking at the piston and head(there should be LITTLE bit of carbon on them)

If it were mine it'd be getting torn completely down for a bottom-up rebuild and some porting.
Hondas4Life3 wrote:
I agree there is no way to know if there are still bits of the ring in the bottom end unless you take it all apart...
I agree there is no way to know if there are still bits of the ring in the bottom end unless you take it all apart. The crank at 25 hours is probably fine so new crank bearings/seals is probably all thats needed for the bottom.

Buy a leak down tester.
gameover wrote:
....I'm beggining to think that the motor might have to come off too. I just sent the head to Eric Gorr and it would suck if...
....I'm beggining to think that the motor might have to come off too.

I just sent the head to Eric Gorr and it would suck if pieces of the rings screw everything again.

What did you figure out was the cause? How is it running now?

Post a reply to: 2015 Husqvarna TC250 top end