Jackshaft Not maintaining enough to get up hills

[FurryOnTheInside]

I'm sorry if my post above didn't make it clear that I was talking about fixing the loss of compression and the torque for the m8 head stud nuts not any of the m6 nuts. 19Nm would be more than double the maximum for cast aluminium m6 threads.

 

[Sitherus]

I'm sorry if my post above didn't make it clear that I was talking about fixing the loss of compression and the torque for the m8 head stud nuts not any of the m6 nuts. 19Nm would be more than double the maximum for cast aluminium m6 threads.

I wasn't blaming you. I was blaming my stupidity, and letting everyone know what was up and why I wouldn't be able to run terror tests for a few days.

 

[FurryOnTheInside]

I wasn't blaming you. I was blaming my stupidity, and letting everyone know what was up and why I wouldn't be able to run terror tests for a few days.

Phew.

I'm glad that you have a new cylinder already in the works.
I should make a start on my spare too.. after I get up and running. I noticed that the cylinder has very minimal material around the ports and idk if it's possible to open them up as much as the first cylinder I bought. Gaskets are going to be thinnnn..

 

[Sitherus]

is this a good buy? https://www.gasbike.net/products/gt80-ported-cylinder

 

[Steve Best]

This is the typical result of not using a torque wrench.
Damage, wasted time, needless cost.

You have taken more time and money right now, than if you had gone to O'Reilly Auto Parts and borrowed a torque wrench.
https://www.oreillyauto.com/rental-tools
You really do need to buy a 3/8" or 1/4" torque wrench:
For about $20:

Or for about $30

The Quick Steel might work if you glue the stud in place, not if you drill and thread it.
Proper answer is to buy an M6 helicoil kit, and a torque wrench of course.
With using a torque wrench you will gain a feel for proper torque even when using a wrench.

A hint on porting the cylinder. Bigger is not better.
Open the port windows (only) up wider only. Exhaust wider at the top, intake at the bottom.
Taking off the top of the exhaust will reduce torque, off the bottom is pointless.
Anything more than minor cleanup on the transfers can be very damaging.
Intake port matching will reduce power, as will opening the intake port diameter up beyond 15mm.
Do port match the exhaust by drilling the gasket and exhaust flange with a 19mm (or 3/4") drill.
Set your squish at about 0.030" (0.8mm) using paper gaskets under the cylinder base.

 

[crassius]

the beam tyoe at the top is the one to get - the clicker type will let you strip the threads off something without any warning, while the beam type will show that torque is not rising with the turning

 

[6blueoval9]

[QUOTE="Steve Best,

A hint on porting the cylinder. Bigger is not better.
Open the port windows (only) up wider only. Exhaust wider at the top, intake at the bottom.
Taking off the top of the exhaust will reduce torque, off the bottom is pointless.
Anything more than minor cleanup on the transfers can be very damaging.
Intake port matching will reduce power, as will opening the intake port diameter up beyond 15mm.
Do port match the exhaust by drilling the gasket and exhaust flange with a 19mm (or 3/4") drill.
Set your squish at about 0.030" (0.8mm) using paper gaskets under the cylinder base.[/QUOTE]

Amen.

 

[Sitherus]

The whole problem was I used a torque wrench to 19 nm like posted above I misunderstood what he was saying.
I own a torque wrench but never used it on a bike before usually my car. Is the cylinder body I posted above a good buy?

 

[FurryOnTheInside]

The whole problem was I used a torque wrench to 19 nm like posted above I misunderstood what he was saying.
I own a torque wrench but never used it on a bike before usually my car. Is the cylinder body I posted above a good buy?

That appears to be for a reed valve engine, not for a piston ported engine. The price seems a bit silly. Most people here prefer to do any and all porting and tuning work themselves, it's a large part of the hobby.

 

[gary55]

is this a good buy? https://www.gasbike.net/products/gt80-ported-cylinder

The GT80 cylinder you are showing is for a reed valve engine. If you are not using a reed valve this is not what you want. When ordering a cylinder it is important to know what type piston you have in the engine. What markings are on the rod.