Please need help, very disappointed.

[JVROOM]

I need some help, 66cc, slant head, Jaguar CDI, expansion chamber, reed valve kit,Dellorto carb. Having trouble, tuning, not running a very well, that is inconsistent. Only 11 miles on engine, am I being too impatient and need some break in time? Very disappointed, because old and not sure what to do next.

Years ago I had put a five flags engine kit on the same bike, which was a friction drive roller, wow, it was only, I believe 33.9cc and it ran great, I mean really good, no monkeying around, piece of cake, easily cruise at 25, and I had a top speed, at sea level, of 33, but that was dangerous and scary.

About the only thing I haven't done, is change the wrist pin bearing, but I'm really disappointed, with this Chinese engine and not sure what else to do.

Certainly would appreciate any thoughts and/or guidance. Everybody on this form has been great, sincerely John

 

[BchCruizer]

I need some help, 66cc, slant head, Jaguar CDI, expansion chamber, reed valve kit,Dellorto carb. Having trouble, tuning, not running a very well, that is inconsistent. Only 11 miles on engine, am I being too impatient and need some break in time? Very disappointed, because old and not sure what to do next.

Years ago I had put a five flags engine kit on the same bike, which was a friction drive roller, wow, it was only, I believe 33.9cc and it ran great, I mean really good, no monkeying around, piece of cake, easily cruise at 25, and I had a top speed, at sea level, of 33, but that was dangerous and scary.

About the only thing I haven't done, is change the wrist pin bearing, but I'm really disappointed, with this Chinese engine and not sure what else to do.

Certainly would appreciate any thoughts and/or guidance. Everybody on this form has been great, sincerely John

I would look into another friction drive i prefer bumblebeebolton but i hear the statons are good to. good luck i dont ride the chinese kits to much hassle for something that is supposed to be fun! good luck

 

[IbedaYank]

11 miles is not enough to break in a new motor. you need to ride it easy for the first tank with oil to gas ratio of 20-1 very the rpm but do NOT run it WTFO for more then a few seconds at a time do this for at least the first tank of fuel

 

[Fabian]

What ignition curve is the Jaguar CDI set to?
What kind of reed valve intake do you have?
Have you changed the jetting to suit the reed valve intake?

I have not had any power or reliability improvement with a Dellorto clone carburettor (but i can't talk for a genuine Dellorto), so i reverted back to the standard NT carburettor which operated just as well.

 

[Fabian]

My 2-stroke Chinese engine runs terrifically well; the reed valve intake runs beautifully and the Jaguar CDI has been reliable and very effective at solving the problems with the standard CDI.

The NT carburettor runs with surprising consistency.

 

[JVROOM]

The Jaguar CDI is set to the default position, I think B as received. I believe that was the recommendation. The Reed valve kit is from rocksolid. I have re-jetted. A few running a little rich, a lot of Hills around here and I'm having trouble figuring that part out. Because it's just running very consistent. May have a fuel delivery problem will change the fuel filter. May go back to the stock carburetor as suggested. Consider myself a decent mechanic that this thing is running inconsistent. Thank you for all your help, John

 

[Fabian]

If you are running the slant head, the compression will be quite a bit higher than the conventional straight plug low compression cylinder head. I would be inclined to set the Jaguar CDI to the lowest ignition advance curve (to start off) with both jumpers attached to A & B

The Rock Solid Engines reed valve intake is a jewel like piece of billet art work, and it performs quite well, once the jetting is correct.
In my situation the jetting needed a massive increase over standard (8 jet sizes) to account for the complete lack of reversion, which is something that i was expecting, but i didn't expect it to be such a large increase.

With a billet Rock Solid Intake tube and (optimised) standard jetting, which in my case was a No 70, gave an EGT of 450 degrees celsius when working hard. With the Rock Solid Engines reed valve intake and a No 78 jet, it still runs at 450 degrees, so the air/fuel ratio hasn't changed despite the jetting increase.
This proves two things a) the jetting is correct and b) the reed valve intake has virtually stopped all reversion.

More telling is that everything is on the money; the colour of the plug with reed valve intake matches the colour of the plug from the setup with the Rock Solid Engines billet intake tube.

When i first installed the billet reed valve intake (with a No 70 jet) it ran quite poorly, which is what i was expecting, and i spent the next three hours messing around with jet size increases of a maximum 4 jet sizes and looking for air leaks.
It frazzled my brain as 4 jet sizes still had the engine running lean, but i thought it (must) be getting on the rich side. I wasted so much time looking for air leaks because it was obvious that it was running lean as soon as i jumped on the bike and rode it 50 meters down the street.

Eventually i just placed a No 80 jet in the carburettor and i could feel it running rich, so i went down to a No 78 and it cleaned up the carburation beautifully, but just slightly rich. I then went down to a No 76 and it was running right on the limit, maybe just a touch lean, so back in went the No 78 jet and i felt that joyful feeling of carburation perfection, which also slightly improved the low and midrange torque over a No 76 jet, but that torque increase was nothing compared to the midrange torque improvement of the reed valve intake

After 2 of my next door neighbours tested my bike with the reed valve intake, they both ordered one and have since installed it on their bikes, to good effect.
Prior to their bikes running correctly and prior to me giving them hints on jetting, they both *****ed and moaned about the engine running like a bucket of c.r.a.p when installing the reed valve intake on standard jetting.

 

[BchCruizer]

If you are running the slant head, the compression will be quite a bit higher than the conventional straight plug low compression cylinder head. I would be inclined to set the Jaguar CDI to the lowest ignition advance curve (to start off) with both jumpers attached to A & B

The Rock Solid Engines reed valve intake is a jewel like piece of billet art work, and it performs quite well, once the jetting is correct.
In my situation the jetting needed a massive increase over standard (8 jet sizes) to account for the complete lack of reversion, which is something that i was expecting, but i didn't expect it to be such a large increase.

With a billet Rock Solid Intake tube and (optimised) standard jetting, which in my case was a No 70, gave an EGT of 450 degrees celsius when working hard. With the Rock Solid Engines reed valve intake and a No 78 jet, it still runs at 450 degrees, so the air/fuel ratio hasn't changed despite the jetting increase.
This proves two things a) the jetting is correct and b) the reed valve intake has virtually stopped all reversion.

More telling is that everything is on the money; the colour of the plug with reed valve intake matches the colour of the plug from the setup with the Rock Solid Engines billet intake tube.

When i first installed the billet reed valve intake (with a No 70 jet) it ran quite poorly, which is what i was expecting, and i spent the next three hours messing around with jet size increases of a maximum 4 jet sizes and looking for air leaks.
It frazzled my brain as 4 jet sizes still had the engine running lean, but i thought it (must) be getting on the rich side. I wasted so much time looking for air leaks because it was obvious that it was running lean as soon as i jumped on the bike and rode it 50 meters down the street.

Eventually i just placed a No 80 jet in the carburettor and i could feel it running rich, so i went down to a No 78 and it cleaned up the carburation beautifully, but just slightly rich. I then went down to a No 76 and it was running right on the limit, maybe just a touch lean, so back in went the No 78 jet and i felt that joyful feeling of carburation perfection, which also slightly improved the low and midrange torque over a No 76 jet, but that torque increase was nothing compared to the midrange torque improvement of the reed valve intake

After 2 of my next door neighbours tested my bike with the reed valve intake, they both ordered one and have since installed it on their bikes, to good effect.
Prior to their bikes running correctly and prior to me giving them hints on jetting, they both *****ed and moaned about the engine running like a bucket of c.r.a.p when installing the reed valve intake on standard jetting.

Motorized biking shouldn't be this difficult. your supposes to buy your kit install it and ride ride ride..not work work ride..

 

[Fabian]

@ BchCruizer

I read your comment and my first thought (actually you don't really want to know my first thought); suffice to say that it was an asinine comment on your behalf. It's plainly obvious that you haven't researched how a reed valve intake works, because standard jetting on a standard style intake tube cannot be transferred to a reed valve intake. They are two totally different systems and they work in two totally different ways, so it would be safe to assume that the fueling requirements will be completely different, and two bikes in two different locations will have different jetting requirements depending on air density, air temperature and humidity. The jetting for someone riding in Miami is not applicable to someone riding in New York.

Motorized bicycling isn't difficult, though it can be challenging when making significant changes to the electronics or the mechanical systems or the fueling system.
My reed valve intake (to date) has over 3,000 kilometers on it; still working to perfection, and i wouldn't even think of going back to a conventional intake tube.

3 hours of messing around with jets could have been shortened to 30 seconds if a twin needle Walbro carburettor was fitted; which is the type of carburettor everyone should install on their engine. Having said that, (even with a Walbro carburettor) there are people who could still f&*k up the carburation with ineptitude - so short of electronic fuel injection it isn't a completely idiot proof system.

Unfortunately Rock Solid Engines still hasn't released their (reed valve compatible) Walbro carburettor, but the moment it is released, it'll be fitted to my bike.

 

[Fabian]

Opps, i spoke too soon: Rock Solid Engines has just released their reed valve compatible Walbro carburettor

http://shop.rocksolidengines.com.au/index.php?option=com_virtuemart&page=shop.product_details&flypage=flypage.tpl&product_id=287&Itemid=1