Motorized Bicycle Engine Kit Forum  

Sponsors



Go Back   Motorized Bicycle Engine Kit Forum > Bicycle Motor > Norm's 2 stroke repair center

Norm's 2 stroke repair center Having problems with your 2 stroke engine? Just ask Norm, he loves to tinker and troubleshoot engines

Reply
 
Thread Tools Display Modes
  #11  
Old 02-27-2008, 10:04 PM
Norman's Avatar
Norman Norman is offline
LORD VADER Moderator
 
Join Date: Jan 2008
Location: pampa texas
Posts: 2,605
Default Re: total tear down

it bolts together with 1/4-20 bolts. rough looking


this is how it would be used to ream out the bushing if I had pressed in a new bushing lacking a ream you might be able to hone it to size with a brake hone. If you get a bushing from a dealer after it is pressed in it might not need to be reamed.
Attached Images
File Type: jpg totalteardown031.jpg (18.9 KB, 675 views)
File Type: jpg totalteardown029.jpg (24.4 KB, 1128 views)
Reply With Quote
  #12  
Old 02-27-2008, 10:14 PM
Norman's Avatar
Norman Norman is offline
LORD VADER Moderator
 
Join Date: Jan 2008
Location: pampa texas
Posts: 2,605
Default Re: total tear down

this is the shaft that the cluth rides on and the front drive sprocket all layed out in the way it goes together I'm pointing out the clutch spring this is what puts pressure on the plates and not the little spring out between the plates. under the clutch spring in the picture is the shaft that goes inside of the main cross shaft. it is the shaft that the flower nut attaches to and pushes the pressre plate off the clutch pads pretty cool how it works. I reassembled this and greased the inner shaft and the bearing.
Attached Images
File Type: jpg totalteardown033.jpg (38.2 KB, 1126 views)
Reply With Quote
  #13  
Old 02-27-2008, 10:55 PM
Norman's Avatar
Norman Norman is offline
LORD VADER Moderator
 
Join Date: Jan 2008
Location: pampa texas
Posts: 2,605
Default Re: total tear down

using typing paper I push the screws through it and screw them into the block to hold the paper then rub with dirty fingers to transfer an image of the gasket area on to the paper. I then remove the paper and cover it with scotch tape to build up the paper and so it won't tear then cut out the insideof the gasket pattern until it fits the part. I left the out side of the gasket pattern lots of room to make it stronger. I can trim the gasket after it is in place and all tighten up.


you can see how the pattern turned out. the hole for the shaft is left small and is cut to size after all the bolts are in the case and tight. that is when I trim the outside part of the gasket as well using an exacto knife the gasket is fugly but this is how to make it easy and not tear.


a very small amount of gasket glue on the outer couple of edges to help hold it while putting the screws in place I don't use alot and only in the places you can see.This side has a raised lip and its the side i pressed the flywheel into fisrt then install the gasket and the other side pulling it down with the case screws turning each a little at a time


closing up the crankcase take your time and it will all go together. Put all screws in place to help hold the gasket in place then screw all screws a little at a time to close the case. Trim the excess gasket material on the outer parts of the case with an exacto knife to make it look nice and don't forget to trim the excess in the cylinder hole and the cross shaft hole. I found this to be the easiest way to get that thin gasket inplace with out tearing it. sort of cheating but it works. I took great care to make the gasket fit the rasied lip around the case as you can't trim it later. the patterm I make made helped to make it all fairly easy. the pattern took 4 tries before I was happy with it and could use it.
Attached Images
File Type: jpg totalteardown032.jpg (12.9 KB, 783 views)
File Type: jpg totalteardown034.jpg (16.7 KB, 699 views)
File Type: jpg totalteardown035.jpg (24.5 KB, 885 views)
File Type: jpg totalteardown036.jpg (20.0 KB, 959 views)
Reply With Quote
  #14  
Old 02-27-2008, 11:04 PM
Norman's Avatar
Norman Norman is offline
LORD VADER Moderator
 
Join Date: Jan 2008
Location: pampa texas
Posts: 2,605
Default Re: total tear down

thought I'd show you how to make a simple bushing puller


how to make the puller into a bushing installer

my sorry quicky puller I used a big nut instead of tubing. I should have left the pictures big it hard to read the board I hope you get the idea I could redo this if you need me to sometime.
Attached Images
File Type: jpg totalteardown037.jpg (20.3 KB, 729 views)
File Type: jpg totalteardown038.jpg (20.5 KB, 581 views)
File Type: jpg totalteardown039.jpg (23.8 KB, 864 views)
Reply With Quote
  #15  
Old 02-27-2008, 11:13 PM
Norman's Avatar
Norman Norman is offline
LORD VADER Moderator
 
Join Date: Jan 2008
Location: pampa texas
Posts: 2,605
Default Re: total tear down

pushed the shaft back into the case from the clutch side the bearing will sit recessed in the case,the bearing will bottom out on a machined lip inside the case.


looking at the side where the sprocket will go after the bearing is pressed in place the bearing will also fit in the case recessed and will bottom out on a machined lip and you can't drive it in any farther


the bearing is being put on the sprocket side of the shaft
Attached Images
File Type: jpg totalteardown040.jpg (23.0 KB, 640 views)
File Type: jpg totalteardown041.jpg (23.2 KB, 626 views)
File Type: jpg totalteardown042.jpg (24.4 KB, 719 views)
Reply With Quote
  #16  
Old 02-27-2008, 11:26 PM
Norman's Avatar
Norman Norman is offline
LORD VADER Moderator
 
Join Date: Jan 2008
Location: pampa texas
Posts: 2,605
Default Re: total tear down

not really pressed I'm not beating the heck out of it either


this is the hole where the clutch cable mounts in. I grease the hole with my grease gun until grease comes out around the bearings then I dig out the grease in the hole and wipe off the excess grease on the bearings this will lube up the shaft and all the insides of the shaft parts. I do this on all the engines when I put them in the first time. I dig the grease out of the hole where I put it in so if it expands it has a place to go. it might be over kill as you saw what was hiding behind the clutch when I first took it off.


you can see the grease coming out around the metal seal area of the bearing stop when you see it.
****** UP DATE********************************************** ****************
If you can just pack the bearing with grease and lightly coat the moving parts of the clutch rod with grease. There really isn't a need to fill the through shaft area with grease.
Attached Images
File Type: jpg totalteardown043.jpg (25.5 KB, 776 views)
File Type: jpg totalteardown044.jpg (20.6 KB, 870 views)
File Type: jpg totalteardown045.jpg (22.3 KB, 828 views)

Last edited by Norman; 01-02-2013 at 06:46 PM.
Reply With Quote
  #17  
Old 02-27-2008, 11:41 PM
Norman's Avatar
Norman Norman is offline
LORD VADER Moderator
 
Join Date: Jan 2008
Location: pampa texas
Posts: 2,605
Default Re: total tear down

Ok all of the shafts get their parts put back on the clutch the sprocket and the front gear along with the keys and lock washers a small amount of lock tight will help if you want. The front gear is a woodruff key (half moon looking thing) it can be a little hard to get in place so you will need to use pliers to press it into its seating area or a brass drift to tap it home all of the bolts are right hand threads so it easy to put back together. Tighten up the clutch and sprocket nuts then put on the front gear tighten the screw down with out the star locking washer to seat the gear then put on the star washer and if you have it use a hand impact wrench to tighten up the screw. notice the rag?! that is how I lock up the thing to take off or put on the gears.
well all of the rest of the engine assembly has been posted before except for installing the wrist pin and the wrist pin keeper. I use needle nose pliers to put the keeper back in place and when you get it in the keeper will spin freely in the groove put rags around the crankcase cause you don't want that wrist pin keeper flying into the crankcase if you loose the battle puting it back in the piston the first couple of tries. I forgot to take a picture of that. anyway that is about all for this time. I need to post on a front wheel bearing cleaning and repacking sometime.unless someone else wants to.

The screw/bolt that holds the small gear on the crank shaft size::: metric die that fits this thread is M8 1.0 threads are 12mm long head is aprox 16mm in dia.
Attached Images
File Type: jpg totalteardown046.jpg (23.9 KB, 714 views)

Last edited by Norman; 08-23-2011 at 03:49 PM.
Reply With Quote
  #18  
Old 03-01-2008, 05:58 AM
Bikeguy Joe Bikeguy Joe is offline
Godfather of Motorized Bicycles
 
Join Date: Jan 2008
Location: up north now
Posts: 11,531
Default Re: total tear down

Quote:
Originally Posted by Norman View Post
Here is where i got into trouble I took this apart don't to it as about 56 little ball bearing will go all over the place and hide on you what a pain it was to find them all at least I keep the floor clean so I found them and it was not fun to put back together. Lots of 4 letter word like darn and dang. What looks like dirt or grease is the sorry little bearings plotting against me on which way to run next


Big sprocket I have that fit to press all back together. Grease used to hold the ball bearings in place. If you just got to take it apart don't say I didn't warn you.

I have the solution!

Find a magnet from an old speaker and put it on the offending parts and the ball bearings MAY stay put.

If they don't, use the magent to help "find" them and pick them up.

BTW, this is post 3000 for this site!

yay
Reply With Quote
  #19  
Old 03-01-2008, 05:59 AM
Bikeguy Joe Bikeguy Joe is offline
Godfather of Motorized Bicycles
 
Join Date: Jan 2008
Location: up north now
Posts: 11,531
Default re: bicycle engine tear down

BTW- Thanks for yet another exellent picture tutorial!
Reply With Quote
  #20  
Old 03-23-2008, 10:12 PM
misteright1_99's Avatar
misteright1_99 misteright1_99 is offline
Motorized Bicycle Elite Member
 
Join Date: Mar 2008
Location: Treasure Coast, Florida
Posts: 716
Default re: bicycle engine tear down

Norm I love your posts and pics they are VERY informative. I would like to know what type of grease you use. I noticed you and alot of other members use a RED grease.
Thanks George...
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 05:11 PM.


Sponsors

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
MotorBicycling.com