complete rebuild - Sportbike Addicts

NYCSTRIPES · 05-22-2007, 01:58 PM

Well, knew this type of thing was coming eventually. I had to pull the motor on the TZ250 and replace the crank. I was half way through the top end and I found a bent connecting rod. That turned into dropping the motor and pulling the crank shaft out for replacement. Then I will re-do the top end like I had originally planned...Good thing I had a new crank ready to go. Half way there, pulled the crank, have the replacement on the ready, cleaned up the cases and getting ready to apply sealant and re-assemble.
Wish me luck, first time re-build.
Ken

SAXON117 · 05-22-2007, 03:30 PM

Quote:

Originally Posted by NYCSTRIPES

Well, knew this type of thing was coming eventually. I had to pull the motor on the TZ250 and replace the crank. I was half way through the top end and I found a bent connecting rod. That turned into dropping the motor and pulling the crank shaft out for replacement. Then I will re-do the top end like I had originally planned...Good thing I had a new crank ready to go. Half way there, pulled the crank, have the replacement on the ready, cleaned up the cases and getting ready to apply sealant and re-assemble.
Wish me luck, first time re-build.
Ken

post up some pix of the project.

***carl_g*** · 05-22-2007, 03:41 PM

have you ridden this thing yet?

NYCSTRIPES · 05-22-2007, 08:17 PM

Unfortunatley just in the neighborhood. Hoping for some track time after this is completed. I managed to get the new crank in, as well as assemble the complete top end. Looking to get the motor back in tomorrow morning.
Good thing I had to do this re-build. I found a couple of problems that needed to be rectified from the previous owner's last work on the top end. One of the head gaskets was missing leaving coolant to seep into the motor and the bolts on the head itself were loose enough to become an issue. Now she's got a fresh top and bottom end.
After getting the motor back in tomorrow morning, I have to get the ignition timing done and she'll be ready to run in the new parts. This was a faster job than I though possible for my first time out.
Ken

Roland Cushway rebuilt crank going in...

Cyl#2 assembled, getting ready to torqe everything down

EvilSteve · 05-23-2007, 04:28 PM

Nice, thanks for the pics.

SAXON117 · 05-23-2007, 04:51 PM

good job man, keep us posted on your progress and as always pix. This is something a little different than the usual bike stuff. Very interesting

NYCSTRIPES · 05-23-2007, 07:00 PM

Hit a snag today, got the bike completely back together and no joy. Something is amiss in the transmission. Art Diaz had a mechanical starter in his paddock and since I was havine some trouble getting the bike running, I used his mechanical starter at Summit, had the rear wheel spinning pretty quickly, tried to drop it into 2nd and heard a CLUNK.
Now I cannot connect with any gears...
When I opened the top end of the motor, I discovered why the bike was hard to start, half of the inner head o-ring was missing and the motor was taking in and burning coolant. Sadly, the things that happened afterwards caused me more problems this week.
I opened up the motor to find the bent connecting rod, but now I know that the rod was a secondary issue. Something in the transmission popped and caused the connecting rod to twist.
I have to drop the transmission soon and see what broke.
I tried to get a jump start and this has cost me dearly....expensive lesson learned.
More pics to follow.

NYCSTRIPES · 05-23-2007, 08:25 PM

I just got off the phone with someone who knows TZ250's very well. He explained that the leaking head gasket caused the left cylinder to fill with coolant water. The coolant caused the crank to bend when enough of it filled the cylinder. Hydraulic lock up was the definition of the problem. Basic physics, you cannot compress water...hence the bent connecting rod.
He gave me some direction for getting the transmission problem solved.
Pulling the transmission tomorrow....a seek and find mission is about to begin.
Ken

NYCSTRIPES · 05-24-2007, 11:04 PM

Success. I found that the grear behind the clutch housing was not engaging the primary drive gear. Took apart the transmision twice today before identifying the problem, got the bike started and she's up and running. Very excited, looking forward to getting this thing on onto VIR Patriot and North this weekend. Wish me luck, I am sure going to need it.
Ken

***carl_g*** · 05-24-2007, 11:15 PM

Quote:

Originally Posted by NYCSTRIPES

Success. I found that the grear behind the clutch housing was not engaging the primary drive gear. Took apart the transmision twice today before identifying the problem, got the bike started and she's up and running. Very excited, looking forward to getting this thing on onto VIR Patriot and North this weekend. Wish me luck, I am sure going to need it.
Ken

Awesome.... Have a great time!!

EvilSteve · 05-29-2007, 03:26 PM

How'd it go Ken?

NYCSTRIPES · 05-29-2007, 06:07 PM

Just got home, lots to tell. Ran the TZ250, had a great time until the clutch went. Simple fix. I also have to adjust the floats in the carbs...getting too much fuel.
It was great fun in the turns, everyone else was on the brakes, I was on the gas..

Yesterday I had a good day on VIR North until 2 sessions before the end of the day, I crashed the TLR in turn #4. Pretty sore today, otherwise I am OK. I will post pictures of the newly re-modeled TLR tomorrow.
Good to meet some of the fellas here over the weekend, had a great time as ususal, except for the crash.

Also thanks to Joe, Bob, Ant and Matt for stopping by and making sure I was OK, really appreciated that.
Ken

***Cakes206*** · 05-30-2007, 09:55 AM

Quote:

Originally Posted by NYCSTRIPES

Also thanks to Joe, Bob, Ant and Matt for stopping by and making sure I was OK, really appreciated that.
Ken

No worries Ken, saw the crash truck from across the paddock w/the TL and immediately said,"Oh crap." Glad to see you were up and ok in your pit area.

Meatball rocks!

IrocRob · 05-30-2007, 10:20 AM

Quote:

Originally Posted by Cakes982

Meatball rocks!

Yeah, but does he roll?

Good to hear you're okay Ken, bikes can be fixed.

**FigNewTon** · 05-30-2007, 07:51 PM

Quote:

Originally Posted by NYCSTRIPES

Also thanks to Joe, Bob, Ant and Matt for stopping by and making sure I was OK, really appreciated that.
Ken

No need to thank us Ken. We all just wanted to make sure you were all right and see if you needed a hand with anything. Bike is repairable you are the important part.

BTW... the ice packs on the dogs were great