How to split cases

E

ERV JR

New Member
new guy here . I built my bike about 3 weeks ago and have maybe 100 miles on it. The other nigh the engine licked up. Its the bottom end. I pulled the jug off and clutch cover . I was able to tap the crank on the clutch side and the crank then turned freely and then stopped again.
There is alot of black junk crap, maybe carbon or maybe gasket material in the crankcase and also metal , I assunme a bearing cage ot something.
I am new to 2 strokes, but am a mechanic by trade,and have built passanger car, marine and race car engines.
If someone could please give me a break down on how to remove the flywheel or clutch plate so i can split the case and see what the damage is that would be great.
 
Last edited:
Re: hoe to split cases

ERV JR said:
If someone could please give me a break down on how to remove the flywheel or clutch plate so i can split the case and see what the damage is that would be great.
Click to expand...
You need a special puller that usually comes with your kit.
I have a box of them if you need one.
 
Re: hoe to split cases

MotorBicycleRacing said:
You need a special puller that usually comes with your kit.
I have a box of them if you need one.
Click to expand...

Well there wasnt a puller in the kit . The kit I got seemed really cheap, the engine was painted silver and the reast of the stuff in the kit appeared to be cheaper than what most of my friends kits came with .
I would have to pull the small sproket off with the puller and then see what happened . I am not sure what the cost will be to rebuild it by the time I get bearings and gaskets or if replacing one part that failed and a few gaskets is all thats needed.
I am tempted to tig weld some mounts into the frame so that I can set the engine at the angle that i want, since the fisrt time I just wanted it running so that I could tow the kids in the trailer to the park for the 4th. also tempted to fix it put it back together and give the bike to my wife and start with another baike and build mounts,replace the head and port it and an dget aq pipe and have a fun bike. But would like to spend more time working on the race car than on a bike
 
well my father inlaw had a puller but like the rest of the kit it was china quality and after pulling the sproket and small gear I attempted to pull the clutch and the puller stripped
 
The tools are cheap. Recommendation.... Make sure the threads are clean on all gears and puller. Might need a SMALL 3 corner file to clean up the tool teeth. I work the tool in and out of the gear by hand and a wrench, making sure it will bottom out inside the gear. A little cutting oil helps. Doing the above...all three of my gear puller tools can be bottomed out in the gear by using my hand, then I can put a wrench on to tighten it down.
 
Well I got it apart , it lost the crank bearing. The woodruff key for the clutch was half way out the groove and smashed betheen the clutch shaft and clutch. Th clutch shaft threads dont look too good either.

I think by the time I get a gasket set, bearings and replace the clutch and shaft I should just get the shortblock from thatsdax.
There two diff ones on the site how do I know what one I need
 
better off just biting the bullet and get just the motor as not all motors are made the same

that I know of there are 3 pistons available for the 66cc/so called 80cc there are at lest 2 heads for the 66cc that I know of and these parts do NOT interchange
 
Ibedayank said:
better off just biting the bullet and get just the motor as not all motors are made the same

that I know of there are 3 pistons available for the 66cc/so called 80cc there are at lest 2 heads for the 66cc that I know of and these parts do NOT interchange
Click to expand...

they list a type J and type D , How do figure out that I have ? Will the casting marks on the rod tell what legth the rod is ?
Aslong and I get the shortblock with the correct rod length I would be using the top end from my engine and piston
 
lets try this again....


not all motors are made the same therefore not all parts fit all motors
only way to make sure is to order from the same place for all parts.... even that does not work all the time gasbike.net / BGF from ebay

Buying the motor from DAX all the parts he sells will fit that motor


that's just the way it is when you buy cheap made in china crap
 
ERV JR said:
they list a type J and type D , How do figure out that I have ? Will the casting marks on the rod tell what legth the rod is ?
Aslong and I get the shortblock with the correct rod length I would be using the top end from my engine and piston
Click to expand...
Where did you buy your motor from?
Do you know what brand or factory made it?
 
yeah it was from ebay. I found this forum after I had ordered it. I had assumed that they would all work together. I assumed it was like all the china crap for bbc,sbc,bbf,sbf stuff. I thought it would be like a Scat,rpm,eagle or ohio crank deal. I assumed they used the same castings and it was just a diff in finish machine work.
After reading I have found that isnt the case . but still assumed that it if the stroke and rod length the topend would work. I thought it would be listed as a whatever stroke and whatever bore
 
BTW there is more crap in the crankcase it this little engine that I have seen in a blower or nitrous engine . **** wed have slapped stuff back together at the track for the next round faster than I had this little engine back together.

Where do you guys rec buying an engine from ?
 
This is a press I made to split the cases, and press the crankshaft out of the block half. It works on both sides.

picture.php


picture.php
 
Ibedayank said:
lets try this again....


not all motors are made the same therefore not all parts fit all motors
only way to make sure is to order from the same place for all parts.... even that does not work all the time gasbike.net / BGF from ebay

Buying the motor from DAX all the parts he sells will fit that motor


that's just the way it is when you buy cheap made in china crap
Click to expand...

Ibedayank said:
better off just biting the bullet and get just the motor as not all motors are made the same

that I know of there are 3 pistons available for the 66cc/so called 80cc there are at lest 2 heads for the 66cc that I know of and these parts do NOT interchange
Click to expand...

ERV JR said:
Ok I reread what you posted and the way it sounded was that if I bought the engine from then the parts would fit but never said that I should purchase the engine from .
Is it not possible to use a set of calipers and a mic to figure out what engine I have
Click to expand...


Now what part of this did you not understand

they look alike but are NOT the same

dealers only sell what fits the they motors they sell....
 
Ibedayank said:
Now what part of this did you not understand

they look alike but are NOT the same

dealers only sell what fits the they motors they sell....
Click to expand...

ok never mind . I understand what you are saying but see my point . The dealers stateside dont have there own castings or moulds. There is a foundry in CHINA that casts them, I should say a few of them. With that said if there 5 diff moulds and 10 people selling them then someone is selling the same parts as another.
I understand your point and it may be hard to source parts
 
Best practice is to buy your motor and your parts from same dealer, you've got the best chance of them working together that way. That's why it's better to buy your motor from a company thats been around a while and will be around in the future, so you can go back to them for parts and advice.
A lot of people crack on Grubee kits cause they cost a buck or two more, but I buy Grubee cause they are probably the most widely distributed HT motor and when you are buying parts you just need to know if they fit a Grubee, cause you know what you got...
 
You must log in or register to reply here.
Back
Top