Building an engine

GoldenMotor.com

aparra619

New Member
Sep 20, 2013
5
0
0
sd
Hi I am new to this and i have not been able to find a forum to help me put a top end and bottom end together. its a 2 stroke engine and bot parts are new.
Thanks
Alex
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Welcome to the forum.
Is this a Chinese 2 stroke bicycle engine? Where did you buy it? Was it disassembled when you got it? Some suppliers are now selling engines in parts to get passed current EPA import regulations. I assume this is what you have but we do need more information.
Assembly isn't difficult but you need a certain degree of basic engine knowledge to do it right.
Get back to us with some particulars and we can offer more assistance.

Tom
 

aparra619

New Member
Sep 20, 2013
5
0
0
sd
I am not to sure if you are familiar with DAX Motors. I bought the top and bottom end of an F80 2 stroke type D gen IV. if you go towards the bottom of this page http://www.thatsdax.com/ENGINE_KIT_PARTS_PAGE_3.html you will see the motor.
And yes it is for a bicycle. I have some knowledge on how to build it. For instance, i know the piston clips/rings should be at a 12 o'clock or 6 o'clock position and to use a lot of syn 2 stroke oil in the cylinder and put some in the bottom end.
 

Nashville Kat

Well-Known Member
Apr 20, 2009
1,501
55
48
Jacksonville, Florida
The one major difference to know is- I believe- whether the engine block (jug) studs are 6 mm or 8mm.

I believe- and there may be exceptions I'm not aware of- almost all top ends will fit the 6 mm stud bottom, except those specifically 8mm

6mm is an older standard, and while 66 motors and top ends still come in 6mm,
there's a gradual change to 8mm in 66 cc motors.

That's part of this game- some suppliers and their stocks may be YEARS behind trends otherwise. 8 mm studs in 66 motors began a few years back and has become more common I'm sure, but if you have a concern or preference you really have to ask a vendor.

It's getting harder these days to come by either 6mm stud bottoms and 50 cc parts, though they are as of now still generally available, their share of the market decreases

Too bad I think- after almost 5 years, I sorta prefer a smaller motor- and mostly for the carburetion aspect- they decrease in revs quicker and idle better, even if they aren't as powerful.

for instance- boygofast was largely selling bottom end with 6 mm studs until very recently- now advertising only 8mm -
 
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mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
I am not to sure if you are familiar with DAX Motors. I bought the top and bottom end of an F80 2 stroke type D gen IV. if you go towards the bottom of this page http://www.thatsdax.com/ENGINE_KIT_PARTS_PAGE_3.html you will see the motor.
And yes it is for a bicycle. I have some knowledge on how to build it. For instance, i know the piston clips/rings should be at a 12 o'clock or 6 o'clock position and to use a lot of syn 2 stroke oil in the cylinder and put some in the bottom end.
Well you got an excellent engine there , piston ringsmost line upwith pins in ring grooves that prevents ring rom rotating in grooves, a dab of oil on cylinder on lower bearings is all thats needed.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
I sounds like he's talking about the wrist pin clips. Most of us know them as E-clips.
and yes my stars always a line .
LMAOlaff
After re-reading the post I think you're right, not sure what the 12 o'clock 6 o'clock is for with the wrist pin retainer clips, but it wont hurt anything just the same so that isn't an issue, piston rings placement is though.....

If I had the time I would make a simple straight forward video of installing a complete top end on a lower from start to torquing the head nuts. Someone with a good video camera needs to make a very clear easy to understand video that will walk a noob one step at a time through a correct top end install so we could send them straight to it and they could even use it as a reference throughout the process.

When I get my lower that is on order I may try to do one and see of my camera will shoot it good enough to be used as a tutorial.

Map
.wee.
 

Scott.D.Lang

Member
Jan 1, 2013
406
2
16
Chicago
I only have one question how do you have the gen 4 bottom and top end when dax is not shipping them out till the 23/24th of this month. the dates were told to me by the owner of ThatDax for when hes shipping them.
 

Scott.D.Lang

Member
Jan 1, 2013
406
2
16
Chicago
to tell the truth its hard to give advice when I have no idea how much you really know about building motors. I can say there are a few good you tube vids that will show you everything you need to know for the most part. one other thing when you tq down your head do it in a criss cross manner and in 3 stages. first stage should should be 40 in lbs second should be 80 in lbs and third should be 120 in lbs. at least that is the tq I tightin mine down to on my last dax motor.