Knocking gt8o

[zippinaround]

209$ just to replate? Yikes!!! Haha something I'll never be doing I guess

 

[Jdh]

How do I correct the port timing for higher rpm?

 

[Jdh]

The cylinder has a third transfer port and I have the arrow reed vale. What mods to the piston do you recommend?
I've heard oof stuffing the case, what's the benefit of stuffing the case and how do I do it? Jaguar I'm going to buy one of your cdi's. How much is it and how do I get it? I want optimum performance out of this engine is the sbp expansion chamber sufficient or would I be better off with a kx 80 or some other dirt bike chamber?

 

[Jdh]

I have 29 inch wheels and a 40 tooth rear sprocket. 37.5 mph is all I've been able to get out of this set up.what can I do to increase mph. Is this a respectful speed for this combo?

 

[Jdh]

Will drilling holes in both sides of the piston help performance of a reed valve engine? I've heard of milling intake side of piston to match intake port do you recommend this?

 

[Jdh]

Can I get the damaged cylinder replated or do I need to replate a new one?

 

[butre]

Will drilling holes in both sides of the piston help performance of a reed valve engine? I've heard of milling intake side of piston to match intake port do you recommend this?

for the intake side, go ahead and cut a big chunk out. leave the exhaust side as it is. if the exhaust is ever open to the crankcase the engine will run like garbage if at all.

it's cheaper to replace a damaged cylinder than to get it replated, and often times damaged cylinders can't be replated.

 

[Jdh]

I just replaced cylinder, piston, rings, wrist pin and needle bearing. Engine is still knocking though. Does anyone have any ideas of what it could be?

 

[Jdh]

for the intake side, go ahead and cut a big chunk out. leave the exhaust side as it is. if the exhaust is ever open to the crankcase the engine will run like garbage if at all.

it's cheaper to replace a damaged cylinder than to get it replated, and often times damaged cylinders can't be replated.

I replaced cylinder, piston, rings, wrist pin and needle bearings. Engine still knocks though. I was hoping the new wrist pin and needle bearings would fix it. Any ideas what else it could be?

 

[Steve Best]

No, 37mph is slightly low for what you have.
Yes, you need a ported piston to run a reed valve efficiently. It can be drilled on the intake side only.
Knock, knock... What is your squish measurement? Measure with 0.060" (1.5mm) electronics solder.
It should be 0.020" to 0.060" (0.5mm to 1.5mm). Ideally o.030"
You might be making head contact.

Is your sparkplug aimed to the rear? It helps eliminate detonation in close cases.

Try running a colder plug.