new engine block?

OK, trying to fix my compression, I think I ruined my block. For background, I have a Minarelli V1 engine on a 1977 Bianchi Snark. Everything was fine, until my compression came loose about two weeks ago ... then the problems snowballed.

My head bolts were all stripped on one end, so I attempted a drastic solution. Not yet knowing about the helio-coil solution, I used JD Weld to hold the stripped ends of the bolt firmly into the engine block. It seemed to work. Two of them are holding tight and firm. But the other tow are still spinning in their groves. One came out, the other might be loose but not come out ... I haven't tried pulling it out since I'm afraid to break it off while inside the block.

I'm sure I have not hope but to try more JD Weld on the other two bolts and hope they hold this time, eh? But ... what if I need a new block?

How difficult is that? How do I do it? Is there anything else I can do to save my moped? Her engine is strong and she's in great (and I mean GREAT) shape. She ran extremely reliably all last season and through the winter. Now that Spring is upon us ... I want her on the road again everyday.

Any help would be great. Thanks.

Re: new engine block?

gimmejimme /

Are the studs stripped or where they screw into the block stripped out?

You'll probably should remove the head and cylinder to repair the stud holes, it's no big deal if you take your time. I don't know what this JD Weld stuff is, sounds like it some kind of epoxy metal repair, but it didn't work.

The heli-coil is the way to go, but you'll have to remove the studs from that JD junk, put a double locked nut on the top of stud so you can get a wrench on it. You'll have to buy/borrow a propane torch to heat up the JD Weld, that should get the studs out, then install the heli-coils by the instructions, you may need a tap and die set to clean up the studs and hole.

If this sounds too involved, check out a machine shop or MC repair shop, but hang in there, I'm sure you'll get more ideas posted on this problem.

The next time you consider JD, make sure it's in a bottle and is from Tennessee.


Re: new engine block?

Actually, it's JB Weld, and it's a liquid welding solution. So I'm not sure if I can even get the bolts out. The bolts were threaded, not the block itself (as far as I can tell).

However ... I did manage to get the loose bolt out! I put more (and a better solution of) JB Weld on and tightened the two up real good. I'm letting it sit for a while (it's supposed to sit for 4-6 hrs).

I'll try (again!) to put the cylinder and head back on later this afternoon and see what happens. I hope it works! God, please let it work!

But I look forward to hearing more posts ... I know I can get "Lucia" up and running around again. Even if it means a whole new damn block ...

Re: new engine block?

Ron Brown /



What you are doing with JB weld is very temporary, if it works at all.

Take a stud to the local auto parts or good hardware store and buy a helicoil kit, it is not that expensive. You may need to buy extra coils as some kits come with two of each length.

A helicoiled repair is much better than the original and will outlast the rest of the ped.

Just make sure you do not get metal shavings in the crank case and that the coils you use are not longer than the original thread if it is a through hole.

Use rags in the crank case opening and put heavy grease on the drill and tap, this will keep most of the small metal pieces attached so you can wipe them off.

I want your next post to tell us how the helicoiling went.

I am wagging my finger at you furiously Miguel, USE HELICOILS. :-)


Re: new engine block?

Sorry Ron ... I didn't even KNOW about helicoils until you posted them. This JB Weld stuff sure isn't working. I even tried more ... and am waiting to see if I can get the bolts to hold on.

I will definitely use Helicoils the next time around. And I'll start looking for a place that can do it. How easy is it to do myself? I'm so deathly afraid of doing something that will forever kill my moped.

But ... to my original question ... how difficult would it be to just plain get a new engine block and start from scratch?

knock knock

......Oh.... Miguelllllll................ Yer gonna give Ron an ulllllllllllllcer!

I suppose you could get a new "block' or set of cases for a Minarelli.

.................................But there is no need to.

And, it would cost a few buck$....($300??)

And you would still have to remove/replace/reinstall a lot of stuff.

Take 30 minutes at a desk with a phone book and call every

moped shop

motorcycle shop

and lawnmower shop

in the book and simply ask them "I need to find somebody who will install 4 heli-coils in my moped engine ... they are small ones and they are very easy access... Do you do that kind of work?"... If they say ....No... Ask them if they know somebody who does.

try those... if they won't do it


auto garages

and machine shops

Some of them will treat you badly because mopeds get no respect... Just expect that.

And expect to pay bout $100 or so.

There has got to be somebody local who can do that... It is not that difficult... If I lived 30 miles from you... I would come over and do it..... but....

Re: new engine block?

Ron Brown /


I was about the third person to recommend helicoils and if you read my post you will see that the instructions come with the helicoils and that the finished job is better than new because you now have steel threads instead of aluminum.

If you are worried about screwing it up, pun intended, have someone watch the angle of the drill when you clean out the holes. If you get this straight, re-tapping is easy.

If possible, recruit someone with some metal working experience, but this is not essential.

Dont drill the holes any deeper than you have to if they are closed ended. Same with tapping and as you tap, turn 1/2 turn in, then 1/4 turn back, this will clear the chips. If the hole is deep, back the tap out from time to time and clean and re-grease it.

Go for it. It is the ONLY way to fix it.


Re: knock knock

Ron Brown /

Thanks Fred,

Maybe between the two of us we can get his attention. :-)


Re: new engine block?

Ok guys, this isn

Re: new engine block?

Ron Brown /


Don't sweat it. We are not really mad at Miguel, just trying to get his attention.

Once you have used helicoils, you will never look back. You will find yourself helicoiling threads in aluminum just in case they go bad some day. :-)


Re: new engine block?

Reeperette /

Oh Krishna...I will put the damn things in.

What are you doin next weekend (Apr7-8) Mig ? cause if you wish, get the coil set and I will show ya how it's done, gratis.

I've had this exact problem with a couple of Tomos Bullets before cause the threading on the bottom end where they go in was soft aluminum, and they strip damn-easy.

It's not that hard to do, just a little time consuming, and like's been said - make really, really SURE not to get any metal bits in the engine.

But then, if ya want, you'll get to see fer yerself.


Re: new engine block?

Thanks all, Fred, Ron, Ree ... you guys are awesome sources of information and help. Well, I left the ped w/ "Moped Bill", the repair guru of the Moped Army and we're going to use helicoils (which he suggested, too!). I think he can do it right. If not ... we'll see. If you want to come, Ree, you're more than welcome. I'm a bit busy the early part of the weekend, but maybe we can work something out. But I'm pretty sure Bill can get it ... man, I so hope so! I want to ride NOW!!

Also, for future reference ... I have an Italian parts connection in Italy. Super cheap and very good. Let me know if you ever need anything. He got me a complete carb for $28 (shipping included!).

Re: new engine block?

Dave the Dude /

I have worked in machine shops and the aeorspace industry for close to thirty years. Heli-coils are the way to go in aluminum blocks. Heli-coils are used in both aircraft and space applications because aluminum is usually so soft. As a matter of fact, it used to be that anyone who wanted to beef up their Volkswagen Bug would put heli-coils in the block.

If, by some tremendous misfortune, the heli-coil installation goes bad for some reason, the next step is to install Keenserts. Keenserts are available from machine shop supply outfits. They are solid steel inserts and use a larger diameter tap drill than do heli-coils. They also use standard taps instead of heli-coil taps. The only trick is to knock in the locking tangs without a special tool. But let's hope that no one has to go the Keensert route.

Re: new engine block?

OK, I'm going for a whole replacement engine. Not to worry, my Italian connection is sending it for only a hundred. So that should work out fine in the end.

I'll take the old engine and use try to tap the helicoils when I have the tools/time. At worst, I can have a spare engine for a future moped, eh?

Thanks for all the help. I'm sure my Bianch will be up and running soon enough.

Re: new engine block?

Good news. One of the Army's Minarelli gurus, Dave B, finished replacing the engine last night. I haven't seen my "Lucia" yet ... but I've been told she runs and hits 33 mph. So I'm extremely happy to hear all this.

Too bad I wrecked a good engine ... but it was a painful lesson to learn. From now on, only helicoils for me.

Oh, to feel the wind in my hair again!

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