Multi-problemed bike (electrical + ???)

[ImaginativeFig]

When I went to return the compression test kit to the bike shop, I showed them the camshaft, they said it looked it was due to low oil and that the cylinder/piston were probably toast too, so I lifted the rest of the cylinder head up to have a look and everything looked unmarred and generally kosher in there, so it's probably alright (right???)

Tried to fiddle with the valves to determine their salvageability... how easily are they supposed to move? Mine didn't move at all with me just pushing with my fingers. I guess maybe they got dried up and non-move-y and provided the resistance to snap the camshaft?

[blaine]

Originally Posted by ImaginativeFig

When I went to return the compression test kit to the bike shop, I showed them the camshaft, they said it looked it was due to low oil and that the cylinder/piston were probably toast too, so I lifted the rest of the cylinder head up to have a look and everything looked unmarred and generally kosher in there, so it's probably alright (right???)

Tried to fiddle with the valves to determine their salvageability... how easily are they supposed to move? Mine didn't move at all with me just pushing with my fingers. I guess maybe they got dried up and non-move-y and provided the resistance to snap the camshaft?

The valves take a fair bit of pressure to move them.Way more than you can exert with your hand.That was my thoughts all along....damage from low oil.I would be worried about the bearing being ruined in the bottom end (crankshaft) If it were me I would find a complete engine so your not throwing good money after bad.

[ImaginativeFig]

Can I check that bearing in some relatively easy way? (Haha, I'm suspecting 'no!')
I already paid for the head, but it hasn't shipped yet, so I think I can still cancel.
Not seeing any particularly appealing prices for full engines--still better prices than buying a new cylinder head from the bike shop, but still $75 on a part that I don't have to take the whole engine off the bike to replace looks sooo nice, but I'm seeing effects of laziness on my machine, so.... I'm torn. I can afford $75 right now, anything over $250 would have to wait a couple of paychecks/'til after rent's paid.

[blaine]

Originally Posted by ImaginativeFig

Can I check that bearing in some relatively easy way? (Haha, I'm suspecting 'no!')
I already paid for the head, but it hasn't shipped yet, so I think I can still cancel.
Not seeing any particularly appealing prices for full engines--still better prices than buying a new cylinder head from the bike shop, but still $75 on a part that I don't have to take the whole engine off the bike to replace looks sooo nice, but I'm seeing effects of laziness on my machine, so.... I'm torn. I can afford $75 right now, anything over $250 would have to wait a couple of paychecks/'til after rent's paid.

No easy to check without a total teardown/rebuild.I hate to be a bearer of bad news.But I would hate to see you spend time/money on a head only to have bottom of engine go bad because of lack of oil to bearings.

[Water Warrior 2]

I think it may be worth the gamble with just doing the head if the cylinder looks good. If, as suggested it was low oil then the cam may have been the only casualty due to being higher and receiving the least oil flow. Thinking positively, you may have just found an engine with a somewhat faulty cam that finally expired.
If you do the head only and find out the engine is bad and knocking you then have lots of experience and a usable head to re-sell.
Yes this is easy for me to say because I am not doing the work but if the budget is getting thin and rent is due...........................

[b1pig]

someone correct me if i'm wrong... despite different exterior cosmetic stuff... is the TU250 engine physically the same?

cheap TU engine
http://www.ebay.com/itm/2009-Suzuki-...fbb159&vxp=mtr


gz engine
http://www.ebay.com/itm/10-Suzuki-Ma...ac4044&vxp=mtr

gz head
http://www.ebay.com/itm/SUZUKI-LT250...52fec6&vxp=mtr

gz head
http://www.ebay.com/itm/CYLINDER-HEA...13d46f&vxp=mtr



I came late into this...
just remember that the ethanol gas has around a 45 day "shelf life" to it. you have to add stabilizers for it to last longer than that. the GZ carb is a PAIN to keep clean. i've had to disassemble and clean my wife's GZ carb 3 times.

The enrichment cable is also a pain. our bike live in a garage, and hers still corrodes. you have to be careful about it, but you have to remove the cable from the bike completely. (14mm wrench on the carb end) once you get the plunger and spring off (again, be careful) I put one end in a bench vice. I then slowly spray WD40/PB Blaster/ETC... down the end in my hand. usually the carb end. Once I feel like I get the thing soaked, I start working that cable a little. bending and twisting slightly as i go... until i get it worked loose. it takes a LOT of work, but its practically free. evenutally spray oil down both ends of the cable.

after you get a head or engine...
a little trick for getting it to pull fuel/prime.
with the petcock in PRIME, the bowl should fill. pull the side cover off the left side and expose the inlet for the airbox. put two or three fingers over the inlet to the airbox and hit start. you should feel the engine pull against your fingers. thats a "real" choke and it will speed up the starting process.

hope you get it fixed and running.

[jonathan180iq]

That's a break at a stress point, not at something that looks like it would overheat and shear apart because of low oil. I think it's broken due to a manufacturing flaw in the casting process of the metal. We've seen something similar once before in someone's case. I think it may have been BadBob, but I don't recall.

I could be wrong... That being said, the head it leaking and the bike was nearly out of oil anyway when you went to check it. So......

Hmmmmm...

Thinking....


I still think your best bets are to either do a complete tear down and rebuild or to simply replace the engine, of which I'm leaning towards the latter. Like WW said, the big concern if it is oil is damage to the main bearing.

Let's say you replace the needed parts, get your timing dialed in, spec your valves, everything looks good and it runs. You'll ride the bike for a few days, a couple of weeks, maybe even a couple of months, and then you'll suddenly, out of nowhere, the bike just stops making power. It just won't go. You coast to a stop and hear hissing and seeping oil and blue white misty smoke everywhere and then you're back at square one, having to replace the engine.

It sucks, I know. internal damage is the worst kind to have. But just suck it up, do it right, and enjoy the bike. (I feel for you on the $$ end. Do your due diligence while shopping. It will pay off. Try Alibaba.

EDIT: Blaine - not WW.

[grasshopper]

ImaginativeFig.....How is it working out with your gz250?

[ImaginativeFig]

Sorry I haven't been posting. I got the replacement head and everything inside it was fine and dandy. The outside has weird coloration, I think someone painted it black long ago (it's an '83, the paint [if that's what it is] is pretty flaked...), it also had no carb boot, which is fine, since mine original's still fine, the big setback is that 3 of the exhaust bolts were shorn off in their holes, so I've spent the last 3 weeks off and on trying to get those loose.
I sprayed them with some PB'laster, used a torch to attempt to loosen by expanding the aluminum, then double nutted the longest one to try and get it out, but only wound up shearing it off flush. I've handed it over to a blacksmith/machining friend of mine and he's working on it as I type. If he can't do it, I might try to see if I can get a hold of some Tap Out Kit (which appears to be Nitric acid, which supposedly eats steel, but leaves aluminum alone due to how it oxidizes)

[grasshopper]

Good to see you back. Those bolts can be a real pain! Sounds like you have all the options. I hope one of them works out for you. Your friend should be able to get those out for you. Best of luck with Iffy and hopefully you'll be riding again soon. Keep us posted.