[MrKitty]

I agree with what you're saying about fcc's. They take up needed crank volume and are more then often unbalanced. They aren't really beneficial. Smoother crank bearings are a better choice.

I once went real strict with my squish and ended up ruining about 4 aluminum pull starts. From that I found out the plastic pull starts were better because they would flex more and not just crack like the aluminum ones did. I also started going a little looser on my squish because it was such a pain to start.

Yup the plastic pull start with the matal pawl...
I don't buld them like that anymore either I would rather get a summer worth the fun out of an engine and go 5 mph slower then have the engine torn down every weekend.

don't get me wrong I do have an engine like that ready to go on the shelf just in case somebody is trying to race me 🤣

I actually have five engines right now all built different ways some for low end torque some for speed runs all different things for different conditions and I mean why not when I can buy them for around 65$

 

[Atvrunner2]

Agree to disagree. The fingers really don't make a bit of difference. It is an annoying conversation piece at best. They can help rings on one engine but not another.
Are the ports bigger, sure now, they were not when they first came out. They wont be if one ports the nonfingered transfer ports.
Less is always better. Dont port the crap out of it. Dont go crazy with the transfers, don't go too big on the boost port. It all is relative.
In the end these tool based motors only allow so much work before they top off and power desends because too much was done.
A FFC is great for low end power, if you want top end DO NOT use a FFC. They basically are terrible for balance. Only because they are Chinese.
Compression.... I believe Mrkitty meant 0.025-0.027 squish TOO MUCH, yes that is overkill. Said best by boosted306, 0.034-0.036 is best, after break in it will rise and not break your hand on pullstart.
I have NEVER broke a pullstart on a high compression motor, best around 0.038" but I don't pull the thing like I am stealing it.
Run 50:1 with 20% trans fluid replacing the oil. Full synthetic always, not necessarily amsoil and 95 to 100 octane.

Two engines on the shelf pre broke in are best.
I have 7. All different specs, wrote on the box the specs.
In all honest opinion, you dont need to add a boost port.
A good custom exhaust pipe, walbro clone carb wt603t, raise compression, little porting of the transfer ports and exhaust port, rocket key, hp wire mod, reed plate and reed stopper mod, you will be surprised at what that alone can do.

 

[Ruyguy]

Thanks guys for your imput , ive effectively made the passage bigger to accommodate the fcc.. well see , ill probably learn a lot from the results of this first build , so what do you guys think ; just finish off the exhaust port and finally be done with porting? Or make the boost ports “useful” and make them bigger which im honestly not that comfortable with lol, . The fcc will be balanced and trued if needed.

and @Atvrunner2 about the reed stopper mod im going to try flipping the ada style reed cage 90° to have it shoot between and on either side of the crank, i am hesitant to remove to bridges and run 2 full reeds instead on the 2 petal reeds. Dont really know the difference , maybe more stability less flutter but thats all in my reed mod ideas thread

 

[Atvrunner2]

It looks really good, I only made one flow like yours, most I just touchup a little for a uniform flow, but all my current builds I have been selling.
I freeze the bearings and over bake the case halves, one always goes in easy the other never, my luck anyway. I have an impact socket (upside down) on hand that is even with the outside ring ready to go if influence is needed.
I would slap it together and see how it is after breakin.
As for the ada cage, I wouldn't cut it, at least yet, once thats done you can't go back. 90 deg, hmmm, I would use it normal until after breakin, see how the motor feels after a full tank and then try the 90deg, worth a shot. When a lot of work is done and have better/faster flow you need stiffer reeds (the single anyway) to stop reed flutter. Maybe with 2 you can get away with softer ones, fiberglass or carbon fiber.

 

[MrKitty]

I would just go with the plastic intake manifold it is way easier to rework/port.

The other benefit of the plastic is it insulates the carburetor from the engine keeping the carburetor cool helps the fuel and air stay condensed.

 

[Ruyguy]

I would just go with the plastic intake manifold it is way easier to rework/port.

The other benefit of the plastic is it insulates the carburetor from the engine keeping the carburetor cool helps the fuel and air stay condensed.

Yeah i agree with you on the thermal peroperties of the plastic one, ill show you mine , and how the port hole is at a weird place , id like to know of its normal

It looks really good, I only made one flow like yours, most I just touchup a little for a uniform flow, but all my current builds I have been selling.
I freeze the bearings and over bake the case halves, one always goes in easy the other never, my luck anyway. I have an impact socket (upside down) on hand that is even with the outside ring ready to go if influence is needed.
I would slap it together and see how it is after breakin.
As for the ada cage, I wouldn't cut it, at least yet, once thats done you can't go back. 90 deg, hmmm, I would use it normal until after breakin, see how the motor feels after a full tank and then try the 90deg, worth a shot. When a lot of work is done and have better/faster flow you need stiffer reeds (the single anyway) to stop reed flutter. Maybe with 2 you can get away with softer ones, fiberglass or carbon fiber.

alright will do, ive been told to try dry ice one the bearings, ill give it a try and let you know,
Just gotta get that exhaust port wider and find correct specs thanks guys

 

[Atvrunner2]

Ha, I have what was almost a junk motor, after major cleanup, installed the bearings, both dropped right in. First time ever. 400 deg for 10min in the oven, overnight freezer bearings, put 2 stroke full syn oil around the bearings and dropped with a socket for straightening. I will make a thread, it was a wreck, just a quick rebuild to resell with parts I had laying around.

 

[Ruyguy]

Ha, I have what was almost a junk motor, after major cleanup, installed the bearings, both dropped right in. First time ever. 400 deg for 10min in the oven, overnight freezer bearings, put 2 stroke full syn oil around the bearings and dropped with a socket for straightening. I will make a thread, it was a wreck, just a quick rebuild to resell with parts I had laying around.

I just informed myself with our local chemical place.
Minimum order of dry ice is 20lbs and you have to order a week in advance , totaling 150$ Cad ,
Then theres liquid nitrogen , 15.75 Per Liter and 36$ to rent the canister… your idea seems like the least expensive way so ill probably just do that. I think my bearings have been in the freezer since i bought them last summer , hope i can find them 😅 . I saw a video where they say to grease all mating surfaces , but in another video the guys goes at them with acetone and does not add grease after, what you think?

 

[Ruyguy]

Ha, I have what was almost a junk motor, after major cleanup, installed the bearings, both dropped right in. First time ever. 400 deg for 10min in the oven, overnight freezer bearings, put 2 stroke full syn oil around the bearings and dropped with a socket for straightening. I will make a thread, it was a wreck, just a quick rebuild to resell with parts I had laying around.

Then you got mr peacock who shows us 2 methods that i honestly find sketchy . Like acétylène heating around the hubs and dropping in instead of heating the entire case , = uneven expansion
And his other method is just smacking them in with a hammer and a 2x4.. also sketchy for obvious reasons .

 

[MrKitty]

I use a heat gun and freezer but oven and freezer is better there's no reason to bust out the acetylene torch on these delicate parts I do use a plumbing torch to melt the glue they use on the modern CAG engine to hold the flywheel and clutch

 

[Atvrunner2]

I just informed myself with our local chemical place.
Minimum order of dry ice is 20lbs and you have to order a week in advance , totaling 150$ Cad ,
Then theres liquid nitrogen , 15.75 Per Liter and 36$ to rent the canister… your idea seems like the least expensive way so ill probably just do that. I think my bearings have been in the freezer since i bought them last summer , hope i can find them 😅 . I saw a video where they say to grease all mating surfaces , but in another video the guys goes at them with acetone and does not add grease after, what you think?

I have personally only used 2 stroke oil, a few times I didn't use anything, forgot the oil, never had a problem.

 

[Ruyguy]

I just practice tried just hitting in the bearing with a socket to hit both inner and outer race and hit in with hammer and then to take out i used a smaller socket and a hammer to hit the inner race until the bearing came out , now the bearing seems almost loose and like if there was crap in it , but theres nothing , what did i do wrong?

 

[Atvrunner2]

A new bearing?? I wouldn't have removed it after install. But what number is on the bearing?? Hopefully you didnt crack the case. Check that.

 

[Ruyguy]

A new bearing?? I wouldn't have removed it after install. But what number is on the bearing?? Hopefully you didnt crack the case. Check that.

I used an old bearing on an old already broken case, so no worries 👍 so also yes on the size m8

 

[Atvrunner2]

Ah ok. Lol
Did the bearing have a 6000, 6001,.6002 number on it?

 

[Ruyguy]

Ah ok. Lol
Did the bearing have a 6000, 6001,.6002 number on it?

They have no number on them , they came off an other case

 

[Atvrunner2]

I never had any case bearings be loose. I was thinking they might not be the right size.

 

[Ruyguy]

I never had any case bearings be loose. I was thinking they might not be the right size.

Not loose in the case kinda like loose within itself, like the inner race had a bit of play up and down side to side,

 

[MrKitty]

Not loose in the case kinda like loose within itself, like the inner race had a bit of play up and down side to side,

Sounds like that bearing is trash...

 

[Atvrunner2]

Yeah, I agree. Dead bearing.