Rebuilt costs same as box delivered!

[Motorbike Wanabe]

I've come to a crossroads. I've had a Grubee 66cc engine on the Andian for about 1500 miles (since Christmas) and it started to knock down deep where only the gerbils will go. I tore it apart and the lower rod bearing is toast as well as the piston and cylinder. They can't be honed/reused. I don't think that the piston killed it but it didn't help it out any either.

Anyways, I was contemplating rebuilding the engine and doing some special painting so that it would look more like a motorcycle engine than simply a black powerhouse (silver case, black cyclinder and a black head with polished fins) but, when I added up all the goodies, it pretty much came to the same price that I could buy a complete kit from a friend of mine (we bought three kits at a really good deal a while back.) I'm thinking of buying the kit and keeping the extras for use on another bike later. And, I could rebuild the engine that I've got a little at a time, then use it for that other bike.

I was just surprised that the cost would take as much as it did to rebuild. I was thinking that the rebuild could be a little more "clean" than what was sent over from "shinah" because there were parts floating around inside the engine. That's what got into the piston. I checked and both pins for the rings were still in place and so were the clips that hold the piston pin. Not sure what it was but it surely influenced the piston, cylinder and head.

Don't really have a rant to post and I've pretty much made up my mind but, just thought that I'd post my findings just in case someone else might be considering the same thing. Anyone else run into this?

 

[Al.Fisherman]

Like most any other product, it seems cheaper to buy the complete package then individual parts. Could you imagine what a auto or truck would cost buying it in pieces and putting it together? I'd just replace a engine and keep the old for parts in the future.

 

[2door]

Like most any other product, it seems cheaper to buy the complete package then individual parts. Could you imagine what a auto or truck would cost buying it in pieces and putting it together? I'd just replace a engine and keep the old for parts in the future.

Didn't Johnny Cash make a song about doing that? http://www.youtube.com/watch?v=sIuo0KIqD_E
Tom

 

[Motorbike Wanabe]

The interesting thing to me was how all of those $3 and $7 dollar parts add up! I mean, the "large ticket items" were the cylinder and the crankshaft, a whopping $20 bux each!

That's why I'm thinking that I'll keep the parts and eventually put together a custom engine using the parts from the second kit.

You've got the Stone Age, the Bronze Age, the Steel Age and now, the Plastic Age (everything's disposable).

 

[spad4me]

A while back I looked into buying enough happytime engines to enable a decent markup for resale.
For a shipping container of dubious quality happytime engines straight from the factory they were about thirty dollars U.S. each.
The problem is a lot of them are junk .
You as the buyer eat the junk the factory could care less they have already been paid.
The shipping is high.
You have to prepay at first.
There has to be enough markup to cover a lot of losses.

 

[Motorbike Wanabe]

You as the buyer eat the junk the factory could care less they have already been paid.
The shipping is high.
You have to prepay at first.
There has to be enough markup to cover a lot of losses.

I understand the disposability of these engines. Heck, that's why most of us got into it in the first place, they're cheap transportation when all things are considered. I was just surprised at how quickly all of those inexpensive parts added up to be about the cost of a complete kit. Now, like you're saying, a lot of those kits might be defective and building it yourself might eliminate some of those issues (if you build it correctly). On the other side, there's no warranty.

Interesting at how equal-yet-different both options are.

 

[mapbike]

Just wanted to chime in here and say that in the last few months I completely rebuilt a 66cc slant head engine I have, the lowerrod bearing gave it up after about 25-30 miles and totaly destroyed the upper end of the engine, piston, crank, jug, and yes I could have almost bought a new kit for what it cost me to rebuild, but by doing the rebuild I was able to go through every square inch of this engine and do some minor mods like porting, shaving .025 off of cylinder head, upgrading all screws and replacing the junk china grease in the clutch assembly, I also made new keys for all the gears out of grade 5 flat washer material and made everything fit better on all surfaces that I could get too. this engine has 55 miles on it now so it is still just in the break in period, but it runs way better than it ever did before it crashed on me and it pulls me (200lbs) up hills much better than my other bike does and the other bike has a 40T and the new one has a 36T I also made from a kids bike crank sprocket. my older bike runs great and has almost 800miles on it now but the mods I didi on the rebuild has given me a much stronger and just better overall running engine, next step is putting ne of Jims intakes and a good air filter on it which is laying on my table right now that I got from Pirate Cycles last week, and by the way those guys over there are great, quick ship, great price, and I even got some bubble gum and a card out of the deal, great people to deal with in my honest opinion.

So, if you have the time, tools, money, and know how, I highly recommend doing a rebuild for the fun of it and for the peace of mind that comes with knowing every single detail of your engine, below are pics of what my engine was when I started the project and how it has come together so far on the bike.

Many thanks to StrontiumEthics for selling me a great crankshaft with perfect lower bearing and also many thanks to Jim at Manic Mechanic for selling me a new (Correct) piston, pin, rings and retaining clips he had in his shop, I did buy my new jug from BGF on ebay which was around $12-$13 and I put in new clutch pucks I got from him also for $6.00+ship-n, I am going to build an expansion chamber for it soon for sure and put a better carb on it possibly if I cant get the NT to work like I want it too.

I have zero regrets over my rebuild, but I also understand that the rebuild route is not for everyone, so I say rebuild if you can but if not at least go over the new engine with a fine tooth comb before you bust her off, this may save you some trouble......!

 

[corgi1]

Like most any other product, it seems cheaper to buy the complete package then individual parts. Could you imagine what a auto or truck would cost buying it in pieces and putting it together? I'd just replace a engine and keep the old for parts in the future.

And it seems the replacement parts fit as good as Johnny's car parts fit too

 

[Motorbike Wanabe]

Mapbike,

You could substitute your photos for what exactly happened with mine. I've got the same scrub marks on the piston and cylinder that your engine has, almost in the same spot! I'll most likely be rebuilding that engine for another bike. I just picked up another engine to get me on the road for now. Checking out Norm's posts and tearing into my engine was problably the best thing I could have done to help me understand these engines. THe real test will be having a running engine when I get finished with it. Not that I don't think I can do it, I just don't trust my mechanic-- ME!

 

[jimraysr]

Nothing new about replacement parts prices. Back, way back when a Chevy Nova was $9,000, the parts for it were $27,000. I have seen where the same part was used for several years, the 5 year old part was 25 or 30% more than the same part for this years model.

BTW, the Woodruff half round keys are soft metal as they are meant to sheer off and save the expensive parts when something goes wrong.

Jim

 

[mapbike]

Mapbike,

You could substitute your photos for what exactly happened with mine. I've got the same scrub marks on the piston and cylinder that your engine has, almost in the same spot! I'll most likely be rebuilding that engine for another bike. I just picked up another engine to get me on the road for now. Checking out Norm's posts and tearing into my engine was problably the best thing I could have done to help me understand these engines. THe real test will be having a running engine when I get finished with it. Not that I don't think I can do it, I just don't trust my mechanic-- ME!

Yes you are right, it does help to rebuild an engine so it is better understood.

I'm sure you will do just fine with he rebuild in the future, you sound like a patient person so you will take your time and get it right.......
Best wishes, Shan

 

[mapbike]

BTW, the Woodruff half round keys are soft metal as they are meant to sheer off and save the expensive parts when something goes wrong.

Jim[/B][/QUOTE]

The reason I had to make the woodruff keys is because the crankshaft I put back in the engine was designed for different width keys than the ones that were in the other engine, I know I said that the material I used was grade 5 but it may have only been grade 2, I'm not 100% on that but I have made many keys over the years for several different engines without ever having any issues to this point so I'm not concerned about the ones I made for the little China Brat I built, But YES you are right......the keys are designed to shear rather than damage the shaft they are in, but from what I have seen at this point with these engines, if the keys were aluminum and they sheared in would probably ruin the shaft, I've seen this happen several times on American made Briggs & Tec. engines and I can order a new crankshaft for what 3-4 keys cost + shipping if bought online form most vendors.

 

[Motorbike Wanabe]

Well, I just finished the build up of my first HT engine. Surprisingly, it fired up and runs really smooth. Smoother than the "replacement" engine that I had on the bike. It was really interesting how simple these engines are. Pretty straight forward.

Interestingly, I compared the used bearings to the new bearings and while the new ones spun much more freely, it seemed (to my uncalibrated fingers) that the old ones didn't have as much play in them. Could have been because of the grease in them.

I took the bike out for a 4 mile run tonight and it really ran great. Another plus to this is that I've been able to polish out the side covers and paint up the engine just the way I wanted it. I'll have to post pics tomorrow, when I can get some decent pictures. Just wanted to give an update to the thread.

 

[Motorbike Wanabe]

Got some pics of the finished product. I think I'm going to stop working on this bike (if it will let me) and start working on another one. We'll see. Wifey is talking about possibly riding one.

Anyways, here's the bike. I think it looks pretty cool and different.

 

[Motorbike Wanabe]

And HERE's the engine.

 

[mr.charlie]

damm that looks great!

 

[Motorbike Wanabe]

Thanks Mr Charlie! It's been a blast to ride too!

We've got a few bikes in the area now and they're all looking pretty neat. We like going for rides and when we get lunch, we'll just sit back and watch people's reaction through the window. Pretty neat stuff.

 

[mr.charlie]

Thanks Mr Charlie! It's been a blast to ride too!

We've got a few bikes in the area now and they're all looking pretty neat. We like going for rides and when we get lunch, we'll just sit back and watch people's reaction through the window. Pretty neat stuff.

i guess im gonna have to get some sort of bike carrier for my reciever hitch on the s-10 blazer...an start travlin to meet my fellow floridians...i think it would be hot sh&t to ride in a group.....

 

[Motorbike Wanabe]

MB'ers are ALWAYS welcome in Lakeland. We're planning a 35-mile ride down through Bartow and on to Homeland, FL. sometime in the near future. We'll be posting something in the events section of this forum when it gets closer.

Always good stuff riding in a group!