Author Topic: Project "Mini Me" General 5 Star Moped  (Read 9841 times)

0 Members and 1 Guest are viewing this topic.

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Project "Mini Me" General 5 Star Moped
« on: September 10, 2010, 10:38:50 AM »
I picked up this little top-tank rolling chassis, with an engine in a box.
The frame seems to be in nice shape. Seat is solid, and no rust in the tank. The engine is another story.




I've never opened and rebuilt an engine before, so I welcome all comments and tips!

I've ordered a set of gaskets and am about to pick up a rebuild kit with new bearings and seals.
I've got a question about the top end though...



What are my options here? Can I hone this? I can get a new top end kit for $150 that will make it a 75cc (it's 49 now)... thoughts?

Also, you'll love what I did here...

I striped out the hex head bolt trying to open the case... Impact driver was no good... so I went at it with a titanium drill bit... I broke that bit off an inch down into the bolt. I managed to get the head off and split the cases, but I still can't remove the shaft of the bolt... also, the drill bit went in crooked... so I hope I haven't screwed the block up too bad...

Thoughts?

Cheers

Offline zanorak

  • Enthusiast
  • **
  • Posts: 160
  • Surviving the Apocylipse quite well.
Re: Project "Mini Me" General 5 Star Moped
« Reply #1 on: September 10, 2010, 08:18:25 PM »
I wonder if you could drill into the drill bit and tap it? :D Tool steel should be just as good to tap as putting in a helicoil?
That's the top of the cover, not structural. I bet it would hold with a smaller fastener. Of course it won't measure up to the standard of engineering on this site, but I'm the guy who honed out my cylinders with a ridge reamer... ;) I also held my stator on with a machine screw on an old Puch. It worked. Not pretty but I had no money.

Did you drop it in a bucket of oil? Search for dissolving taps. I can't remember just now what was used, but it dissolves steel but not aluminum. Alum? Can't remember.

If it was me I'd go with the bigger piston right off the bat - the kit isn't too expensive and it keeps you from being stuck at 25 mph. Big selling point too. That and a tuned pipe.

We used to take the front forks off of these and mount up small dirtbike forks. If I recall they had the same diameter. Measure. That way you get dampened shocks up front. The stock setup on these is just a spring in a tube and it gives you crazy headshake over 40 from the oscillation. That way you can also mount a nice front brake!

Offline fantino

  • Hot Shot
  • ***
  • Posts: 321
Re: Project "Mini Me" General 5 Star Moped
« Reply #2 on: September 11, 2010, 12:09:38 AM »
Alum (pickling spice you can find at some grocery stores) does indeed dissolve steel out of aluminum with no adverse effects to the aluminum. The only problem is it takes a very long time. You have to be able to submerge the part in a boiling alum solution and let it go for hours (I dissolve a tap out of my cases over the course of a week in several hour sessions). It's a very cheap but very time intensive solution. Good luck!

Offline Grnrngr

  • Master
  • *****
  • Posts: 1,722
Re: Project "Mini Me" General 5 Star Moped
« Reply #3 on: September 11, 2010, 02:38:03 AM »
I'd definitely go for the big bore ;D kit as well..should be an awesome little screamer. Can't you just grab ahold of the stud with vice grips and twist it out? even if it breaks off flush with the case, it would probably get the broken bit out and you could re-drill..a little torch heat might help...
'72 CB750-K2 "PopCycle"
'73 CB750-K2 "Barney"
'77 CB750A   
'83 Virago 500 (red)
'83 Virago 500 (black)

"and so on and so on and scoobydoobydooby..oooooooshasha"  Sly Stone

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #4 on: September 11, 2010, 08:24:09 AM »
I'd definitely go for the big bore ;D kit as well..should be an awesome little screamer. Can't you just grab ahold of the stud with vice grips and twist it out? even if it breaks off flush with the case, it would probably get the broken bit out and you could re-drill..a little torch heat might help...

I've got vice grips on it... It turns about 1/8th turn easily, then sticks hard. I went in crooked with the bit, which is what broke it off I guess.

I was thinking about using the dremel to cut it off flat... but not sure where to go after that. Maybe this alum solution is the way to go.

Can anyone give me ore details?

Also, I'll probably go with the big bore kit... the only question is which one. They make a 75cc, 80cc, and 90cc for my motor! I'm all for the max power, but I worry the 90cc would be less reliable... thoughts?

Offline Grnrngr

  • Master
  • *****
  • Posts: 1,722
Re: Project "Mini Me" General 5 Star Moped
« Reply #5 on: September 11, 2010, 11:41:18 AM »
I'm all for the max power, but I worry the 90cc would be less reliable... thoughts?

That's why ya got pedals... ;D  90cc would be killer!! definitely wanna make sure the brakes are good tho....
I'd keep workin that stub back and forth as tight as you can get it each way, don't cut it flat yet...if it isn't too far into the side, the broken bit may work itself back enough to let the screw out. I'd be interested in learning more about the alum treatment as well, sounds like a good way to go if you have the time.
'72 CB750-K2 "PopCycle"
'73 CB750-K2 "Barney"
'77 CB750A   
'83 Virago 500 (red)
'83 Virago 500 (black)

"and so on and so on and scoobydoobydooby..oooooooshasha"  Sly Stone

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #6 on: September 11, 2010, 04:39:17 PM »
I'm all for the max power, but I worry the 90cc would be less reliable... thoughts?

That's why ya got pedals... ;D  90cc would be killer!! definitely wanna make sure the brakes are good tho....
I'd keep workin that stub back and forth as tight as you can get it each way, don't cut it flat yet...if it isn't too far into the side, the broken bit may work itself back enough to let the screw out. I'd be interested in learning more about the alum treatment as well, sounds like a good way to go if you have the time.

I think anything above 70cc requires opening some passages in the motor for oil?

The alum trick might have to be the way to go... I'll see after it soaks in PB blaster for a week. But it moves freely, then stops hard...so I think it's pretty well stuck

Offline Old75_ratafe

  • CB750 Cave Spelunking
  • Expert
  • ****
  • Posts: 801
  • 1975 CB750K
Re: Project "Mini Me" General 5 Star Moped
« Reply #7 on: September 11, 2010, 11:18:23 PM »
Not sure about most states but around here anything above 50cc, capable of 35mph or more than 2hp is considered a motorcycle and you need lights, plates, license and insurance.  Not saying you have to refrain from the bore kit... But just something to keep in mind if you get pulled over doing 50mph on your scooter ;)
1975 CB750K
Project Back in Black

Sent from my Texas Instruments TI99/4A Computer

Offline putnaja1

  • Hot Shot
  • ***
  • Posts: 485
  • '77 CB 550k -Was gonna cafe, but looks cool stock!
    • Jason's Wacky Website
Re: Project "Mini Me" General 5 Star Moped
« Reply #8 on: September 12, 2010, 07:18:35 AM »
Looks like an awesome project!  Are parts hard to come  by?

Jason
Play Pinball!
My Gallery!
"The world is divided into people who do things, people who get the credit and people who continually criticize.  Try, if you can, to belong to the first class of people.  There's far less competition"

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #9 on: September 12, 2010, 08:06:24 AM »
Looks like an awesome project!  Are parts hard to come  by?

Jason

The parts don't seem to be much of a chalenge yet, and cheap compared to our Honda parts. There are some special tools needed though, I'm working on those now.

In NYC we have 3 classes of mopeds... class C is the one you want... no motorcycle license, no helmet, no insurance required. The decide what class your moped is based on specs out of a guide the DMV has... But they don't inspect the engine for mods. However, you may raise suspicions from a cop if you're doing 50-60mph!

Offline zanorak

  • Enthusiast
  • **
  • Posts: 160
  • Surviving the Apocylipse quite well.
Re: Project "Mini Me" General 5 Star Moped
« Reply #10 on: September 12, 2010, 05:06:25 PM »
It's been my experience that most cops don't know (or care) what kind of moped it is if it's that old. Most of them had one when they were kids too! HA!

Have you tried heat? Somebody else said that. A guy I know suggested I take a soldering iron and lean the tip against the stuck bolt once to heat it up. I'm thinking about trying it some day.  You could always weld to the broken tap too... just don't let it cool too fast or it will get more brittle. (tough one though because of all that aluminum sucking the heat out)

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #11 on: September 14, 2010, 09:07:52 AM »
Ok, I've got a game plan now...

After talking with some moped guys I know and picking their brains about what direction I should take, here is my plan...

I'm going to do away with this head and piston and go with the 75cc polini kit. From what I've heard it's more than enough power and it's super reliable.

I'll order a set of bearings and seals for the bottom end and pray it all goes back together.

I'll upgrade to a 16mm SHA carb, and also a new pipe (though maybe not at first).

I'm going to take the engine to a local shop and see if they will pull the flywheel for me since I lack the proper tool... then I'll try to figure out my drillbit/buried screw issue... unless they happen to have a Minarelli case lying around for cheap.

Once the engine is sorted, I'll get to work on the electrical... which will be a whole other chapter for me...

I'll have more info later

Offline zanorak

  • Enthusiast
  • **
  • Posts: 160
  • Surviving the Apocylipse quite well.
Re: Project "Mini Me" General 5 Star Moped
« Reply #12 on: September 14, 2010, 05:48:46 PM »
If you go for the bigger cylinder you'll have to jet up.

Before you pay some shop to make fun of you for having a moped (been there done that) try renting the puller from the local auto parts store, or just ask if you can give 'er a crank right there on the counter. Make sure you buy a can of brake clean or something if they say yes! ;)

Bearings and seals will be easy though you may have some issues with the rust on the crank. Buy some emery paper or something for exploration I guess?

Some of those were wired so that if a bulb burnt out the bike would quit. Weird "safety" feature or something. This of course can get you flattened by a truck - so REWIRE IT if that's the case! We pretty much remade the wiring harness on my bro's Garelli because they used such crap wire. Once got a free moped because the kid didn't know about the bulb thing - he did EVERYTHING and couldn't get it to start. We replaced the tail light bulb and it was running that afternoon.

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #13 on: September 15, 2010, 09:36:53 AM »
If you go for the bigger cylinder you'll have to jet up.

Before you pay some shop to make fun of you for having a moped (been there done that) try renting the puller from the local auto parts store, or just ask if you can give 'er a crank right there on the counter. Make sure you buy a can of brake clean or something if they say yes! ;)

Bearings and seals will be easy though you may have some issues with the rust on the crank. Buy some emery paper or something for exploration I guess?

Some of those were wired so that if a bulb burnt out the bike would quit. Weird "safety" feature or something. This of course can get you flattened by a truck - so REWIRE IT if that's the case! We pretty much remade the wiring harness on my bro's Garelli because they used such crap wire. Once got a free moped because the kid didn't know about the bulb thing - he did EVERYTHING and couldn't get it to start. We replaced the tail light bulb and it was running that afternoon.

The local shop is a moped shop... so they didn't make fun of me. They pulled the flywheel off for free and I bought the 75cc kit from them.

The wiring is all off the bike, so I'll be starting from scratch. I'm not going to mount the turn signals, just taillight and headlight. I've heard these Generals required the brake light to function in order to run... so I'll keep that in mind.

Emery paper on the crank, huh? Sounds good to me.

The shop guys also said my busted screw shouldn't be much of an issue... since it's on the top of the case on the tranny side... there's no pressure there... they think it will probably be just fine if I cut it flat and forget about it. It's worth a shot I suppose.

Cheers

Offline zanorak

  • Enthusiast
  • **
  • Posts: 160
  • Surviving the Apocylipse quite well.
Re: Project "Mini Me" General 5 Star Moped
« Reply #14 on: September 15, 2010, 10:12:14 AM »
Depends how rusty the crank is. Use common sense I guess.

Good luck!

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #15 on: September 15, 2010, 12:36:48 PM »
Depends how rusty the crank is. Use common sense I guess.

Good luck!

From what I can see, the crank looks OK... but I haven't split the cases yet. I'll know more soon.

I'm getting more frustrated with the PO (don't we always!)... The engine in a box was supposed to be complete, and I was in a hurry so I didn't look too hard... now I'm missing the cylinder head...who knows what else!

It's my fault for not being more thorough...


Offline zanorak

  • Enthusiast
  • **
  • Posts: 160
  • Surviving the Apocylipse quite well.
Re: Project "Mini Me" General 5 Star Moped
« Reply #16 on: September 15, 2010, 05:35:31 PM »
That could be tough. Luckily they're still available if you look. They warp easy though, so check that out or you'll be losing gaskets left and right. Ask me how I know! ;)
Won't the new jug come with a cylinder head?

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #17 on: September 20, 2010, 12:42:34 PM »
Update:

While waiting for a few parts to arrive I stumbled upon another moped (Gloria Blanco) for a good price. It has a running Minarelli V1 that's stock.

So now I have a short term plan and a long term plan...

Short term: trick out the Gloria motor, then swap it over to the General.
Long term: rebuild the current motor and drop it back in the Gloria...then I'll probably sell the Gloria in the spring.

I've still go plenty of "project" left for the General...cleaning, wiring, lights, engine install, mods for the engine, etc... so I'm keeping this thread alive.

Thanks for all the help, I'll post some new pics soon.


Cheers

OWilde

  • Guest
Re: Project "Mini Me" General 5 Star Moped
« Reply #18 on: September 22, 2010, 10:06:44 AM »


I'll be following your progress--don't have much smoker experience,  but I did have a General when growing up in Madison NJ.  Had to mow/rake many a lawn to afford it.  Got 300 miles out of it before it was stolen from the Short Hills Mall parking garage... ???

You have balz to ride in Brooklyn--spent a few months in Midwood and Astoria this year.  Didn't ride much,  but every ride,  was quite sphincter puckering.

Geoff

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #19 on: September 26, 2010, 07:52:57 AM »
Moped riding in Brooklyn is a little sketchy. I try to stick to the slower streets...then haul ass down them :)

Pics are coming, but I've done a bit...

I researched and discovered that the Minarelli motor came in a few configurations (20MPH, 25-30MPH)... The Gloria is the 20MPH version with a highly restricted exhaust and a smaller carb (14.12 MM)... The General motor has the 25-30MPH engine, so the carb is bigger (14.9 MM)...not sure about the exhaust b/c mine doesn't have one!

So I pulled the carb on the Gloria and replaced it with a new Dellorto SHA 16.16MM. At first it wouldn't start so I checked the jet. The jetting was set at 82... I pulled that out and dropped in a 56 and vroom!!

To get her to idle with the 56 I had to screw the idle screw all the way in, but she idles perfectly now... also, she's noticeably faster!

Question: Can I drop to a smaller jet and get it to idle with the idle screw turned out more? Do I care? (remember it idles perfectly right now) Will I lose performance if I drop in the smaller jet?

The General: I've pulled the tank and filled it with vinegar, I'll let it soak a few days. There isn't much rust, but it isn't perfect either. Once I get it clean I'll flush it with 2 stroke oil to leave a protective layer inside until I gas her up.

I'm going to replace the petcock since they're only $15 and I can ensure proper flow. I'm also cleaning up the frame right now.




Cheers

Offline Old75_ratafe

  • CB750 Cave Spelunking
  • Expert
  • ****
  • Posts: 801
  • 1975 CB750K
Re: Project "Mini Me" General 5 Star Moped
« Reply #20 on: September 28, 2010, 12:19:55 AM »
Once you add a exhaust the tuning is all gonna change anyway, I'd wait till u have that squared away to mess with the jets
1975 CB750K
Project Back in Black

Sent from my Texas Instruments TI99/4A Computer

Offline ferroussphinx

  • hello and help me please lol
  • Enthusiast
  • **
  • Posts: 124
  • 1974 honda cb 750
Re: Project "Mini Me" General 5 Star Moped
« Reply #21 on: September 28, 2010, 12:58:59 AM »
o lawdy  please let know   you did not just get some every day scooter dammit you got yourself a


MOPED   it means there is mo to it  he he he heh it means when you run outta gas you can pedal pedal pedal 

hope that does not happen i had a trac when i was thirteen o yea i was cool,  till the clutch kept burning the belt and i could not
afford it because leaf raking season is not as long as mowing season so ha it had to go
anyway  i ran outta gas had to pedal it three blocks o boy it blew badly
honda cb750 1974

Offline Old75_ratafe

  • CB750 Cave Spelunking
  • Expert
  • ****
  • Posts: 801
  • 1975 CB750K
Re: Project "Mini Me" General 5 Star Moped
« Reply #22 on: September 28, 2010, 11:32:09 PM »
You should find a road runner horn.  That way when you blow past someone on it at 50 you can hit it "Mee meeep!"  ;D
1975 CB750K
Project Back in Black

Sent from my Texas Instruments TI99/4A Computer

Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #23 on: September 29, 2010, 07:58:41 AM »
Once you add a exhaust the tuning is all gonna change anyway, I'd wait till u have that squared away to mess with the jets

I'm trying to do the modifications 1 at a time. That way, if it doesn't start, I have less gremlins to track down each time.

As far as the tank goes... The tank had very little rust, but I went ahead and did a vinegar treatment anyway. I removed the petcock and put a cork in its place. Then I filled it with vinegar and let it sit for a few days.

The vinegar worked well, got plenty out of the tank... but finishing the process is difficult.

After I drained the tank I flushed it with water, then added 2 stroke oil and shook it around... but it still flash rusted...

Now the tank looks worse than it did... although this rust is a very thin layer.

I think what I'm going to do next is let it soak for a few more days, and have a full can of pre-mix fuel waiting...then drain the tank of vinegar and immediately fill the tank with fuel.


Offline laser145

  • underfunded
  • Hot Shot
  • ***
  • Posts: 311
Re: Project "Mini Me" General 5 Star Moped
« Reply #24 on: September 29, 2010, 08:00:51 AM »
Forgot:

I've removed the rear wheel and I have 1 broken spoke and many of the others are loose... So I've got to take it by a shop and see if they can true it up.