[roberte]

Hey! Anybody remember me bragging about being able to cruise at 70mph after I changed the front sprocket? Well my piston seized... and yes, it was at 70 mph. Glad there was no one behind me and I was'nt going around a curve. Also glad my wife came and got me--she had sworn she never would again. Anyone have any tips on how to get the piston out of the bore? BTW for all you Bulleteers Uhaul rents a nice little trailor perfect for motorcyles ramp and all for $25 a day.

[ScooterBob]

A big block of wood and a sledgehammer will usually suffice ....... This is a PERFECT example of of why you shouldn't LOAD the engine - but spinning is OK. I'm guessing that while the rpm's were a bit lower, the happy handle had to be twisted a bit farther to keep the wheels turning with the extra gearing. More happy handle - more fuel - more heat - more piston expansion ....... BLAMMO! Also bear in mind that the old engines need a little "charge cooling" to keep piston crown temperatures under control .... jet 'em FAT - it's where it's AT! I'm sad that the little mill  gave up on you - but it's a very valuable lesson. Put 'er back together LOOSE, jet 'er BIG and go have some fun.

BTW - If you haven't already taken the little thing apart - I have had reasonable luck with lots of PB Blaster or other penetrant, a little heat and some screw pressure applied to the top of the melted slug to get it to move. Be careful of the ROD - the cylinder can be bored and the piston is toast ..... Also - take the head apart and see if there are any "Bits-O-Piston" hanging under the exhaust seat - you may need some coarse lapping compound to smear the aluminum off of there - but you ought to be good as gold after that! Best of luck - Keep us in the loop, OK?

[1Blackwolf1]

  Also plenty of swearing can help.  I bought a seized up Suzy up long ago and also used a sharp chisel to mark a break line on the piston after liberal soaking with drain oil.  Gave it a couple taps and tried to turn it over.  Couple taps, kick..took me about an hour of that to break it loose.  And like Scooter says jug was okay..head okay..(after a trip tp the machine shop).  Went .040 over on piston and rings and she lived. 

  Just don't get overly violent with hammer blows.  A good length of 2X4 and a 5 pound hand sledge and patience is what freed mine up.  The piston came out in a number of pieces so I had another job of clean-up..but for a 100 dollar toy..no problem.

[ScooterBob]

If'n a man gets lucky, the slug will glue itself to the jug at or near the bottom of its travel. That way you can loosen the cylinder, raise the piston and rod to TDC and gently whack the cylinder DOWN onto the piston until all is loose. This will preclude breaking the piston (a huge mess as was mentioned) and will keep those evil side loads off the rod if the cylinder is tapped fairly straight. Any way you go at it, patience IS the key - I just spent a SOLID week of gently tapping, heating, tapping, spraying, tapping, heating and spraying some more on my BSA crankcase to get it to come apart after 60 years of being in a damp environment ....... PB Blaster and good Scotch ..... It's the recipe for a remedy! Hahaha! 

[roberte]

Thanks for the advise guys. I did a little looking around on Dan's Motorcycle repair course and found a great solution to a stuck piston; http://www.dansmc.com/stuck_engine.htm Trouble is I don't think I could weld the doodad to the spark plug.

[singhg5]

Hey! Anybody remember me bragging about being able to cruise at 70mph after I changed the front sprocket? Well my piston seized... and yes, it was at 70 mph. Glad there was no one behind me and I was'nt going around a curve. Also glad my wife came and got me--she had sworn she never would again. Anyone have any tips on how to get the piston out of the bore? BTW for all you Bulleteers Uhaul rents a nice little trailor perfect for motorcyles ramp and all for $25 a day.

Sorry to hear that your piston seized and now it is under repairs.  Hope it gets fixed as early as possible and it was lucky that you are ok.

Just for information, was there enough oil in the engine and what grade was the oil ?  Secondly how long were you riding the bike before it happened ?  Was it very hot day or were the roads uphill ?

Some other riders have recommended switching to bigger front sprocket.  So I was thinking about that.  It will be very helpful to know what are the safe riding conditions with bigger sprocket and also what not to do.   

[roberte]

There was enogh oil, I started checking it before each ride when I saw how much it leaked. I am using 20-50W. The stretch where it seized was pretty flat. I think the temperature was about 80 degrees. I had been riding about 45 min. Most of the ride is very hilly. There were other problems that I knew about; I knew the piston & cylinder had a lot of scoring down around the skirt. Some people guessed it was piston slap, others guessed that the piston had seized once before and not been bored or honed out. I put it back together like that cause I didn't want to spend the money right then. The compression was about 95 psi which was attributed to the altitude here. I leaned out the carb a bit and advanced the timing to compensate. I might have gone too far and made it run hot. I'm buying a higher compression piston from ACE to compensate for the altitude this time and I'll put the timing back to stock. I'll be keeping the front sprocket like it is..... the ride is a lot smoother.

[clamp]

You know all this advise about hammering this and that with lumps of wood is not the proper way.

      I would remove head and make a bracket of some sorts that bolted to the barrel. The bracket would have a big nut and a bolt welded to it.

    With barrel secure I would heat up the cylinder with a blow lamp --(not oxy acetylene) then screw down the bolt pushing the piston down. being careful not to push past BDC.

     Once you have it moving lubricate.

     Never hit stuff with hammers, that shock is going right through the crank big end bearings.

[roberte]

Hmmmm.... Now I'm thinking about melting it out. I checked MPs for aluminum and cast iron--looks like about 1000 degrees F difference. Do you think the oil in the crankcase'll ignite if molten piston drops in? Following up on your idea clamp--I could loosen the head and barrel, lift it up so tha t the crank turns a bit,  jam the crank some how and then tighten down the head being careful not to over torque.

[Kevin Mahoney]

Several observations
1. If she won't come get you she is telling you something. As with the wife who supposedly "puts her foot down" (biggest sales objection used in dealerships) you can always get a new wife.

2. I have witnessed SB's patience with disassembling things - to the point of driving me nuts. However he has a lot less self broken parts in his garage but I have a lower Scotch bill.

3, Clamp is right

[Bullet.wagon]

You could also get out your angle grinder and make some relief cuts in the cylinder although rather extreme, try to keep the metal filings out of the crank. Try the Clamp way first.

[roberte]

I don't know if you guys will ever speak to me again..... I started the usual wrestling match with the head (it's stuck even though I got those hardened washers under the head nuts) and decided to check the primary drive during a break. The reason for the seize was the magnet in the alternater broke apart. I don't know what that's about. Maybe the crank bearings are shot and it vibrated the magnet so much it flew apart. Hopefully it was just a defective magnet. I'll let you know.....if anyone's still interested. My only excuse for getting advice on what I figured was a seized piston before I started working on it is that I hate getting stuck in the middle of a job and having to wait for replies to my queries on the forum. Anyway, Tom--if you're reading this, I'll be keeping the piston. It's about time I cleaned up the bore and II'll be interested to see if the increased compression gives me any more power

[ScooterBob]

Several observations

2. I have witnessed SB's patience with disassembling things - to the point of driving me nuts. However he has a lot less self broken parts in his garage but I have a lower Scotch bill.

Over the years of not HAVING any money - and my propensity to work about that which is odd, unusual or hasn't been minted in 75 years, I have learned NOT to break parts as each one is precious .... A little Scotch to settle the nerves is just a bonus!  - and as I have figured out on the latest project, the Scotch is a little cheaper than some of the dang parts! 

[clamp]

Hmmm this is more serious than I thought   (rubs chin).  Its probably the bike,--yes im sure thats the problem ,  you need a bigger one ,--a much bigger one,   say BMW 1100 RS

     I fear that if you were to repair it we would still  be questioned on other failures.

     You seem to be able to demonstrate failures yet un known and unheard of such as alternators reaching max centrifugal force and exploding.

     I rode mine today and looked at the speedometer as I approached  an excessive speed I thought of 65 Km per hour.. My mind wandered to this post whereas the owner was reaching speeds in excess of 120km ph

   Yes, Im sure now,-- that is the problem --you have the wrong bike.

[roberte]

Clamp, you must have me confused with a lesser man-I would never give up on my Bullet. Nor am I a man that flits from bike to bike or even has more than one at a time--leaving the others to pine while I ride one of their mates. True, I test her limits, but she'll never want for attention. I know I don't need to remind you that Burt Monroe's 1920 Indian had a stock top speed of 55mph.

[cyrusb]

Yeah, but Burts bike was anything but an Indian when he was done with it. Putting on a 19 tooth sprocket is not a get out of jail free card for speed. It just enables you to run a less frantic 55-60 mph, as you now know.

[ScooterBob]

Yeah, but Burts bike was anything but an Indian when he was done with it. Putting on a 19 tooth sprocket is not a get out of jail free card for speed. It just enables you to run a less frantic 55-60 mph, as you now know.

And then there's ACE and his FireBall .......... 

[ace.cafe]

And then there's ACE and his FireBall .......... 

Somebody mention ma naim?

When Chumma rides his Fireball on the highway, he's the one who's passing all the cars!
He goes like 80mph everywhere he goes. About a month ago, he got pulled over for doing 90, but the cop let him off.
One thing's for sure, Chumma is about as good of a test rider for torture testing the bike as I could ask for. He really rides that thing hard all the time. And when he's not going fast, he's stuck idling in NYC traffic jams. That bike gets put thru the wringer in every possible way!

You should hear his stories about doing the ton inside the Holland Tunnel with an open megaphone exhaust at about 2am.
I keep expecting to hear that he broke something, but it's going strong!
Almost 20k miles on the bottom end and piston now, and about 5k miles on the head and cams.

[ScooterBob]

Chumma and I should form a company whose motto is "When it absolutely, positively needs to be destroyed overnight .... " Hahaha! I can't break MINE either ...... although I'm told by the local resident Racer that it's "fallen off" a little ..... I may have to crack it and have a look. I skeptible, though ...... 

[roberte]

I took off the exploded magnet. I've been here before (taking off the magnet) when I changed the secondary drive sprocket. I've got some dim memories of having to pry this off or tap on it with a ............um with the tool whose name we shall not mention. I suspect I put a small crack in it at that time. The crank bearing passed the jiggle test, that's about as technical as I get, seems allright to me.