got my cylinder back

[mud runner]

well i have bad news im gonna have to tear my motor appart and split the cases because it it has a bad air leak and when it runs in one spot for about a min. there is a puddle of gas and oil under it but it is a good thig i got auto shop this year i school because thats probably where im gonna do most of the work on it

 

[Budget_Blaster]

well i have bad news im gonna have to tear my motor appart and split the cases because it it has a bad air leak and when it runs in one spot for about a min. there is a puddle of gas and oil under it but it is a good thig i got auto shop this year i school because thats probably where im gonna do most of the work on it

Did you split the cases?

Probably a bad base gasket if you didnt use a good quality gasket and torque it properly.

 

[mud runner]

its not topend its the bottom end heres a pic

its leaking bad there

 

[blasterBruce]

That sucks to see man , hope you get it fixed soon !

 

[mud runner]

same here now i might talk my dad into getting a 3 mill vitos stroker

 

[blasterBruce]

Good luck with that !

 

[motoman159]

same here now i might talk my dad into getting a 3 mill vitos stroker

Or you earn the money ya own damn self!

 

[best]

Hey, before you hog out your intake, you might want to have a look at this opposing view.

Filling in the intake improved the power EVERYWHERE.
The port windows were opened up about 1mm but most of the port was filled in with about 2.5 oz of JBweld and epoxy putty.
This did not constrict the port, but made the port as much as 6mm (1/4") deeper and closer to the reeds.
1/8" aluminum plates were epoxied on both sides of the reed cage too, to take up volume and raise crankcase compression.

Think about this, your carb is only 26mm or about 531mmsq.
Your boost port is 20x8 and your intake ports are 19x20 so even allowing for corner radii your port area is already over 800mmsq.
Why would you want to make your ports 50% larger than your carb can flow?
Your airflow velocity drops off and your fuel drops out of suspension, dribbles to the bottom of the case.

So, your air/fuel mixture goes from a 26mm diameter tube to a huge box. What happens?
Speed drops to nothing, fuel drops out of the air because the air flow is the only thing holding it there.
So you have this big volume of air at very little velocity, what is going to get it past the piston window in the brief time it is open?
Pressure? You OPENED UP THE REED BOX! You have LESS pressure and little velocity available!

By reducing the intake ports to the same area as the port windows and lengthening them and stuffing the reed box
you have kept the velocity up, increased the momentum effect and increased crankcase pressure.
When that piston window opens up you have a battering ram of momentum to ram the mixture through.

Compare the port windows carefully. You can see the bottom ports are about 1mm larger than the stockers above.
But look at the length and straightness of the ports in the bottom.
Not a bit of aluminum was cut off except to open up the windows.
JBweld and epoxy putty was added to straighten and deepen the ports.

How does it work?
No other mod, just filling in the intake tract, made it idle smoother, powerband kicked in lower and yet it now revs higher.
Noticeable seat of the pants improvement everywhere in the powerband.

Now, the next thing will be cutting your chamber and setting up your squish...

 

[Budget_Blaster]

Hey, before you hog out your intake, you might want to have a look at this opposing view.

Filling in the intake improved the power EVERYWHERE.
The port windows were opened up about 1mm but most of the port was filled in with about 2.5 oz of JBweld and epoxy putty.
This did not constrict the port, but made the port as much as 6mm (1/4") deeper and closer to the reeds.
1/8" aluminum plates were epoxied on both sides of the reed cage too, to take up volume and raise crankcase compression.

Think about this, your carb is only 26mm or about 531mmsq.
Your boost port is 20x8 and your intake ports are 19x20 so even allowing for corner radii your port area is already over 800mmsq.
Why would you want to make your ports 50% larger than your carb can flow?
Your airflow velocity drops off and your fuel drops out of suspension, dribbles to the bottom of the case.

So, your air/fuel mixture goes from a 26mm diameter tube to a huge box. What happens?
Speed drops to nothing, fuel drops out of the air because the air flow is the only thing holding it there.
So you have this big volume of air at very little velocity, what is going to get it past the piston window in the brief time it is open?
Pressure? You OPENED UP THE REED BOX! You have LESS pressure and little velocity available!

By reducing the intake ports to the same area as the port windows and lengthening them and stuffing the reed box
you have kept the velocity up, increased the momentum effect and increased crankcase pressure.
When that piston window opens up you have a battering ram of momentum to ram the mixture through.

Compare the port windows carefully. You can see the bottom ports are about 1mm larger than the stockers above.
But look at the length and straightness of the ports in the bottom.
Not a bit of aluminum was cut off except to open up the windows.
JBweld and epoxy putty was added to straighten and deepen the ports.

How does it work?
No other mod, just filling in the intake tract, made it idle smoother, powerband kicked in lower and yet it now revs higher.
Noticeable seat of the pants improvement everywhere in the powerband.

Now, the next thing will be cutting your chamber and setting up your squish...

Yea...about that...i dont know id trust jb weld on anything like that.The last thing you want is that garbage chunking off into peices in the engine.And the aluminum side peices on the reeds look scary.

Before i tried these methods id contact a reputable builder like ken and see what he says.But ill tell you this id be pissed if i got my jug back and it was filled with jb weld.

On the other hand what youre saying is true and makes sense the jb weld though is what i question.If you were tigging more material in id say hell yea.

 

[best]

Yea...about that...i dont know id trust jb weld on anything like that.The last thing you want is that garbage chunking off into peices in the engine.And the aluminum side peices on the reeds look scary.

Before i tried these methods id contact a reputable builder like ken and see what he says.But ill tell you this id be pissed if i got my jug back and it was filled with jb weld.

On the other hand what youre saying is true and makes sense the jb weld though is what i question.If you were tigging more material in id say hell yea.

So, you are saying you have never used JBweld or epoxy in an intake manifold?
And that you have never even HEARD of anyone ever using JBweld or epoxy in an intake port?
WHERE THE HECK HAVE YOU BEEN FOR THE PAST 30 YEARS?

Not as pretty as fresh ground aluminum, but makes more power.

You obviously have not been building your own engines or even reading about those who do.
Back in about the 1980s it was becoming apparent that the beautiful hogged out high flowing ports were not producing the hp numbers everyone was expecting. Ford knew this back in 1970 when they actually decreased the size of the Boss302/351C valve size, and Jeep when they redesigned the 1998 4.0L HO head with significantly smaller ports that made more hp. Ports on all performance engines have gotten smaller in the past 30 years and the very best flow bench guys start and finish their work now by adding putty to see what they can fill in without affecting flow.

I have been putting epoxy in intake ports and 2 stroke crankcases for over 30 years. I originally used Devcon products, but find ordinary cheap JBweld "slow cure" to be wonderful stuff. The "fast cure" is good for trail side repairs but does not have the strength of the slow cure so I feel less inclined to trust it. Right now my KZ1000 bike has steel divider plates "glued" into the intake ports and carb to increase low end torque and fuel mileage. It is my daily driver and long trip tourer. As well, my son is running a Blaster with a 1" hole in the bottom of the crankcase patched with JBweld and fiberglass for the past couple years. Properly done, it is durable stuff.

NO, the JBweld or aluminum side plates will not fall off if done right.

TIG or "tigging" is undesirable. Not used unless you have to on the exhaust and inside the combustion chamber.
The reason for this is because it warps and twists the aluminum and is prone to cracks over time.
IF you were TIGing the ports, where I would do it is fill in the bottom of the exhaust port on the Blaster.
A "ski-jump" hump in there has proved to make more low end torque on other 2stroke motors.

If you are the nervous sort, yeah, hire out the work.
If you want to learn, listen carefully to all sources and try things on you own, one step at a time.
If you want to try epoxy in your ports, I suggest sandblasting them first,to clean them and for grip.
Be careful to protect your cylinder from the sand and to clean it well afterward.
Then JBweld and if you need it thicker, try some of the 2 part puttys.
They will even mix to get the right consistency, but start with JBweld directly on the port surface.
JBweld is water soluble before it is cured, so a wet tool or finger can be used to smooth it.

As for does it work?
I have been rebuilding and hot-rodding engines since taking an automotive mechanics course in 1976.
Later I became a machinist and had even more tools available to me.
I have tried every trick in the book to go faster over the years.
I work in industry and have been trained and get paid to make the machinery work faster and more reliable.
Not all modifications work out, you have to measure results and be honest with yourself about those results.

Most often here I see guys hogging out their reed box mixed in with a dozen other mods.
So there is no telling what worked or didn't. Try it all by itself. You won't like the results.

YES, filling in the reed box and ports on the Blaster gave impressive, "immediately noticeable" results, all by its self.

 

[YZ Otis]

ROFLMAO ... ^^^^^^ ... there's sum great entertainment spiced with info that's not often shared

 

[JonS]

you're worried about getting a 3mil stroker crankshaft with the cases looking like that? clearly your priorities are not in line quite yet.

 

[mud runner]

you're worried about getting a 3mil stroker crankshaft with the cases looking like that? clearly your priorities are not in line quite yet.

we are gonna buy new cases and then when we get them we might might get a stroker but we have to get cases first

 

[mud runner]

well we put alot of jb weld on it for now so i can finish the race season but this winter it will get torn appart im gonna let the jb weld set overnight and first thing in the morning im gonna start it

 

[blasterBruce]

so your not leak testing it ?

 

[Blaaster]

/\ /\ /\ /\ Take note!!!!!!!!!!

Leak test before starting, you do not need any nasty surprises!

 

[blasty 95]

Wow that was alot of reading on a 4 inch screen hahahah

 

[best]

Wow that was alot of reading on a 4 inch screen hahahah

Yeah, yeah, yeah... I guess I'll never get a job with Reader's Digest... <GRIN>

Mud Runner, I never had great luck just putting JBweld on from the outside.
And I second Blaaster's leak test comment. You are wasting your time without it.

Here is triplecrown's JBweld repair thread. It was a huge hole in both case halves.
Most of the picts are terrible, but if you look he did a lot of metal prep and there is fiberglass mesh reinforcing the hole. Still running.
http://www.blasterforum.com/engine-mods-swaps-129/jb-welding-holes-45887/

 

[blasty 95]

^ it was good info thanks.

 

[mud runner]

well it is very fast i ran about a tank and it screams at 3/4 throttle and my dad wont buy or build a leak tester but the jb weld is holding up good we spraied the bottom of the motor with super clean and then wiped it down with acidtone and then put the jb weld on it