new'b on a budget

[paulson_shawn]

I've been tinkering with a 78 special for a couple years now (diy drag pipes, Boyer micro power with Profire coil, rejeted cv38's) but could never get it tuned right. I found cam chain guide pieces in the oil so I pulled the engine ( front mount bolt is seized in case so I pulled it with it still on engine ; ( . Tore down top end to replace chain and guide and found scored stock pistons slopping around in the bores. Would love to just get a big bore kit but from what I've read it won't do much without a cam, exhaust, and carbs to go with it and can't afford all that. So now I have a frame with wheels in the driveway and tore apart engine in my apartment wondering what to do with it. Thinking about cheap 76mm pistons from ebay and standard overhaul for the rest. Everything else looked in good shape except 1 of the valve tips (pitting) . Read about the base gasket delete trick but don't really want to buy dial indicator etc... any advise would be greatly appreciated..

 

[fredintoon]

- - - ( front mount bolt is seized in case so I pulled it with it still on engine) - - -

Hi Shawn,
fer Chrissake man, that's no way to fix a bike, you gotta get that bolt out of there!
Buy, borrow or rent as powerful a 1/2" impact wrench as you can find, that'll shift it. That, heat & penetrating oil for sure.

 

[paulson_shawn]

I tried PB Blaster over night and my and a breaker bar and twisted the head off. Don't know how to get it out now?

 

[paulson_shawn]

There's enough bolt on the other side to lock 2 nuts on. I'll try that with heat and impact if I can borrow 1. Should I heat the bolt or the case?

 

[paulson_shawn]

Decided against a "budget build" gonna do a good street performance build even if it takes me a few years.

 

[fredintoon]

I tried PB Blaster over night and my and a breaker bar and twisted the head off. Don't know how to get it out now?

Hi shawn,
if the bolt head is twisted off the busted bolt you can try driving out.
You will need a maybe 12" length of 3/8" diameter steel rod, a BFH and a hot air paint stripping gun.
Heat the casting to expand it off the broken bolt and pound the bejasus out of the bolt's broken off end with the rod and the BFH.

 

[paulson_shawn]

Thanks for the tip. Ill give it a try. Just for my curiousity tho y drive the broken end through instead of the end the nut was on?

 

[fredintoon]

Thanks for the tip. Ill give it a try. Just for my curiousity tho y drive the broken end through instead of the end the nut was on?

Hi shawn,
the busted end is flush with the frame so the rod won't slip off as easy as it would on the protruding threaded end.
Though come to think of it, you could spin a nut half way on the threads to give the rod a little pocket to sit in.
And you have the busted off head at one side and the threaded end of the bolt with the nut removed on the other?
Can you get at the threaded end well enough to get a good swing at it?
Directly, without a steel bar to transfer the hammer's shock load?
If so, you say there's room for two nuts? Thread one on just level with the end and give it a few sturdy whacks to see if it moves.
If it does, pound it in until the nut hits then go to the other side and pound the sticking out bolt end back in flush again.
A few iterations of this should free it up enough to switch to using the rod to pound it on through.

 

[paulson_shawn]

Good idea! Might have to use a medium FH to get in there.

 

[XSLeo]

A budget, boy are you in for a surprise.
For a very good penetrating fluid mix acetone with ATF 50/50. Apply the heat then spray on this mix. It will cool quickly, this helps draw the fluid in. Then a few taps with the hammer. Easy does it, you don't want to break anything.
As Fred said if you can get it to move a bit one way work it back and forth using plenty of the mix.
It will come out.
On the 750 kit, A added one to my 75. I used the same cam, intake and exhaust. There was a pleasant increase in power. The carbs didn't even need tuning.
A bigger cam and carbs will, just like if you left it a 650 will wake it up some.
I run the 750 just fine with the BS38's I ran on it as a 650. It ran just fine with the BS34's. It runs even better with the EX500 carbs.
So if you want the 750 get it. If you want to add expensive cams and carbs later you can.
Leo

 

[paulson_shawn]

I've had a few bikes in my life but never modified any. I'm. finding out how expensive it is quickly but after deciding to build it how I want it now matter how long it takes I haven't even messed with the engine, been working on the frame the last couple days. I didn't really do much work yet and it all ready looks so much cooler. Thanx for the help,I'll try that mix and heat. As far as performance goes... I thought it ran ok before I took it apart. I knew it was tired but when I saw the scoring and huge gap between the pistons and cylinders and how far the valve timing was off Icouldn't believe it ran at all (and Idid 100 on it once) so I'm thinking the size pistons that will clean up the cylinders and everything sealing and syncing right will be enough performance for me. Thanx again for the help.

 

[paulson_shawn]

Did the 6"+ forks and rebel shocks starve the oil pump? it came with the forks but I added the shocks.