Major Overhaul

[choprpilot76]

Major Manco 388 Overhaul

So I was given an epic go-kart from an old high school friend. From what I was told this is an old Manco 388 that was a legend in it's time for adult size go-karts. The kart was sitting outside for probably 15 years and was EXTREMELY rusted. The frame was about the only usable component, which is in great shape with no rust. I am completely overhauling the kart from the ground up with ALL new components. I already bought a new Predator 212cc engine from Harbor Freight and a new Torques Converter. I have ordered a new axle, axle bearing hangars, axle bearing, sprocket, and brake band. I am taking it tomorrow to get the frame sand blasted. I have a small problem though. The new TQ converter came with a belt that is to small. I got the 30-75 as seen in gopowersports for $119. The belt it cam with is a 699 and it should have come with a 669 or 775. The belt was so tight I had to slightly push it on, which is causing it to have enough tension on it that at idle it is engaged. Every other youtube video I have seen shows a 669 or 775 size belt. Does this sound correct to you? Thank for any help.

Daron

 

[KartFab]

darin, are you sure you installed it correctly?

Also, google "comet belt chart" and you can check your belts dimensions vs the center to center distance and driven diameter.

Ps that kart wasn't a legend, it is timeless/legendary. I fixed one up and it's really fun to drive.

 

[choprpilot76]

Well maybe legendary is a bit over stated, but the guy I spoke to at gopowersports said it was quite the kart when it came out. I wouldn't know, I am brand new to the karting world, this is for my 4 kids. My two older daughters are helping me with this project. I have been checking the measurements and checking online for the belt size/part number. Evey source and youtube video I have seen says it is suppose to use the 669 or the 775. When u look at all the "how to" videos on youtube with the same set up, if u look close enough it shows the actual 669 or 775 labled on the belt. Plus, you can notice some "slack" in the belt when it is statis (idle). The 699 I got is very tight, I have to push it on to the driving pulley, which causes tension on the driving pulley from the get go. Since there is already tension on it, when the engine is started up the driving pulley instantly engages the driven pulley which obviously in turn is driving the 10 tooth sprocket. EVERY video I have seen shows the pulley system statis (not turning) at idle. Honestly I am 100 percent positive it is to small/tight. I am a little bit mechanically inclined, I used to rebuild Apache attack helicopters from the ground up, I have some decent mechanical knowledge. I think maybe at the manufacturers plant they maybe made an easy mistake of seeing 669 when accidentally grabbing the 699 belt to through in the box. Seriously, if u could see it u would see that it is way to tight.

---------- Post added at 10:13 PM ---------- Previous post was at 10:11 PM ----------

KartFab, nice looking ride by the way. I can't wait to see this one in it's finished product.

 

[choprpilot76]

I've been making a lot of progress on this restoration. I completely disassembled the entire cart, the frame and its subcomponents were the only things salvageable, frame, roll cage, spindles, etc. I was able to save the brake drum and polish it to a very nice shine. I had to cut the motor mount off because it was bent and not properly placed to receive the new/different motor and torque converter. Also one of the motor mount rails was cracked and needed repair any way. The paint removal has turned out nicely, although I have a few small cracks to get still. I also had to weld in new seat mount cross bars since the others were very weak, sagging, and rusting badly. I just got the rest of the axle parts in yesterday so I will start assembling the rear, although I do have some challenges with the new torque converter fitting properly back there.

 

[Poboy kartman]

To the forum....Have you tried calling GoPowersports on the belt issue? They would know and might possibly offer the correct belt if applicable....

 

[Kelly Wood]

Hi there Clearfield UT... you still go the front wheels from the first pics and want to make a buck or three? If you're not using them of course.

Nice ride.

Shoot me a pm or something. Maybe we'll hook up.

Kelly (in SLC)

 

[OzFab]

I was able to save the brake drum and polish it to a very nice shine.

Umm, you don't want that, the surface where the band sits needs to be dull & rough, otherwise, the brake will not work...

 

[landuse]

Nice kart. Here is a link to the belt chart

http://www.gokartsupply.com/tcbelts.htm

 

[choprpilot76]

To the forum....Have you tried calling GoPowersports on the belt issue? They would know and might possibly offer the correct belt if applicable....

Yes I have talked to them on the issue and they say I'm the first to complain about it, but I have tried two seperate 669 belts and they are both the same. Hpthey told me it shouldn't be an issue because once the weight of the kart and big 22" wheel are on the ground it shouldn't provide enough torque to move it, and I believe them. They also said that the more tension u can keep on the belt without it moving any ways is good. So since I had two I returned one to them and am ordering the 725 size which is a 1/2" longer. So now I will at least have 2 sizes to choose from and go with the one I like the best.

---------- Post added at 02:39 PM ---------- Previous post was at 02:38 PM ----------

Hi there Clearfield UT... you still go the front wheels from the first pics and want to make a buck or three? If you're not using them of course.

Nice ride.

Shoot me a pm or something. Maybe we'll hook up.

Kelly (in SLC)

ABSOLUTELY!!!! I will PM you with my phone number, plus it would be great to bounce some things off of someone local.

Daron

---------- Post added at 02:41 PM ---------- Previous post was at 02:39 PM ----------

Umm, you don't want that, the surface where the band sits needs to be dull & rough, otherwise, the brake will not work...

Thanks man, I appreciate that, I will rough it up. I was just initially trying to get the corrosion off of it. Thanks for the tip though.

Daron

 

[Kelly Wood]

ABSOLUTELY!!!! I will PM you with my phone number, plus it would be great to bounce some things off of someone local.

Daron

Sir, you rule.

Email was sent a bit ago, we'll talk more soon next week. I wanna check this out in person.

Kelly "Kartrods" Wood

 

[choprpilot76]

So I think I have a problem already. I got the entire rear end assembled and everything is brand new components except the brake drum. The engine tranfers power and drives the rear axle beautifully, HOWEVER when u look at the ends of the axle it has a very very slight wobble to it. Obviously this should be an indication that the axle is slighlty bent. It is a brand new axle from MFG Supply. When I hold it to a straight edge it appears straight, of course the tiniest bend would still probably be hard to see, but it does appear straight. The axle is hung between two standard self-aligning hangar bearings so mounting should be straight. Is there anything I'm missing about these things and how they're mounted or is it just that simple....that it's bent?

 

[Poboy kartman]

JMHO ....But are you saying you see a slight wobble running the axle without wheels?

Bear in mind....a slight variance in perfect trueness shouldn't be a problem until you exceed 100 mph....

Bearings have play in them....they can't work without it....but think about a gyroscope and how that mass not only self-centers itself, but stabilizes the vehicle it's in....

Not only will the wheels do that....but tires have air in them to act as a cushion and shock absorber to minor imperfections in the drivetrain and surface on which they ride....(otherwise, you need a railroad track) ....

Sounds like it's ok to me....

 

[Kelly Wood]

Hey there.

Here's my 2 cents from a few years of hanging axles.
1. Bearings in the hangars first, on the frame, loosely.
2. Axle into the hangars.
3. Place all items on the axle as you slide it all together.
4. Snug up the hangars, make sure the axle still can slide back forth. It might be a little tight but it should move if tapped.
5. Align the items on the axle, snug up items on the axle (brake disc/drum), sprocket carrier, don't worry about the wheels, they're last.
6. Snug up the set screws on the bearings to axle, or use locking collars.

If you snug the set screws in the bearings to the axle, then tighten the carriers, it can cause an otherwise brand new axle to slightly bend.

If that's the case, loosen everything and spin it. You'll know if it's bent or not.

What size axle is it? Have 4 extras here if you use a 1" one with a 3/4 step.

Kelly

 

[choprpilot76]

JMHO ....But are you saying you see a slight wobble running the axle without wheels?

Bear in mind....a slight variance in perfect trueness shouldn't be a problem until you exceed 100 mph....

Bearings have play in them....they can't work without it....but think about a gyroscope and how that mass not only self-centers itself, but stabilizes the vehicle it's in....

Not only will the wheels do that....but tires have air in them to act as a cushion and shock absorber to minor imperfections in the drivetrain and surface on which they ride....(otherwise, you need a railroad track) ....

Sounds like it's ok to me....

Thanks, I understand exactly what you're talking about, I understand gyros. I just didn't think it should be noticeable at a hand rotated speed. I'll try a few more things.

---------- Post added at 07:57 AM ---------- Previous post was at 07:54 AM ----------

Hey there.

Here's my 2 cents from a few years of hanging axles.
1. Bearings in the hangars first, on the frame, loosely.
2. Axle into the hangars.
3. Place all items on the axle as you slide it all together.
4. Snug up the hangars, make sure the axle still can slide back forth. It might be a little tight but it should move if tapped.
5. Align the items on the axle, snug up items on the axle (brake disc/drum), sprocket carrier, don't worry about the wheels, they're last.
6. Snug up the set screws on the bearings to axle, or use locking collars.

If you snug the set screws in the bearings to the axle, then tighten the carriers, it can cause an otherwise brand new axle to slightly bend.

If that's the case, loosen everything and spin it. You'll know if it's bent or not.

What size axle is it? Have 4 extras here if you use a 1" one with a 3/4 step.

Kelly

Hey Kelly, it is 40" axle with a 3/4 step. I think I'll just wait till Tuesday when u come by to grab the front wheels and have u check it out for me. I have a few other questions any way. I think I will try those steps tomorrow and see if it makes a difference.

Daron

 

[choprpilot76]

Some initital engine and axle drive set-up/install pics.

 

[Kelly Wood]

Good looking setup there. Way cooler than my stuff.

Hope you're not done back there... I have some goodies to donate that you might want.