Above 30 mph bogging in colder temp By seanstr (Read 9,022 times)

[seanstr]

OK, I re checked several things.

My valves were off, intake is at .004, exhaust .005. my compression went up further. Damn near 200 psi.

The spark plug indicated lean. Changed the jet from a 110 to a 115 and reset air fuel mixture using the tach. Once it got add high as it would go I then backed off the idler screw until RPM'S got back down to 1800.

Hit up the manifold intake from carb to engine to tighten it up to make sure it's tight.

Pulled if the vacuum from manifold and sucked to see if any fuel was leaking into the manifold, for the extra fuel consumption.

I cannot see a vent hose for the fuel tank so maybe Lance/Sym didn't have one?!

I have not checked the timing. However, I have a spare CDI but I have never liked the way it performed.

I will wait until tomorrow after breakfast. Take it out again for another test drive if anyone sees something a miss like the compression being higher than spec by 15 psi please post asap, thank you in advance.

Do one change and check results.

[seanstr]

I don't have a timing light. I think I since everything appears to be great (got to 7690 RPM'S) but it refuses to go past 45 mph it might just be CDI. To check CDI you need to check timing, so I need a timing light. Like I said, the adjustable CDI is available but last time I tried it out 2 fuses blow right away during start up.



Do one change and check results.

[seanstr]

Nov 27, 2016 2:00:12 GMT -6 seanstr said:

OK, I re checked several things.

My valves were off, intake is at .004, exhaust .005. my compression went up further. Damn near 200 psi.

The spark plug indicated lean. Changed the jet from a 110 to a 115 and reset air fuel mixture using the tach. Once it got add high as it would go I then backed off the idler screw until RPM'S got back down to 1800.

Hit up the manifold intake from carb to engine to tighten it up to make sure it's tight.

Pulled if the vacuum from manifold and sucked to see if any fuel was leaking into the manifold, for the extra fuel consumption.

I cannot see a vent hose for the fuel tank so maybe Lance/Sym didn't have one?!

I have not checked the timing. However, I have a spare CDI but I have never liked the way it performed.

I will wait until tomorrow after breakfast. Take it out again for another test drive if anyone sees something a miss like the compression being higher than spec by 15 psi please post asap, thank you in advance.

So the test drive.

The 115 jet is too large. Maybe need a 112. The jet kit I got is missing that.

Do one change and check results.

[jct842]

One thought out of the blue.........the carb. Do you know for sure it is opening up all the way? besides the mechanical linkage for throttle, inside the carb is the piston....it is actuated by vacuum. A tiny leak in the rubber diaphragm on top will cause the piston to not be drawn up all the way. A rip in the diaphragm will limit the speed to just over idle. A rough spot can limit that piston or slide also.

Your scooter needs more power to get the rpms up/ Right now it seems like it is going uphill instead of running on a level street. Like you need to twist the throttle a bunch more.

[seanstr]

Nov 27, 2016 14:09:04 GMT -6 jct842 said:

One thought out of the blue.........the carb. Do you know for sure it is opening up all the way? besides the mechanical linkage for throttle, inside the carb is the piston....it is actuated by vacuum. A tiny leak in the rubber diaphragm on top will cause the piston to not be drawn up all the way. A rip in the diaphragm will limit the speed to just over idle. A rough spot can limit that piston or slide also.

Your scooter needs more power to get the rpms up/ Right now it seems like it is going uphill instead of running on a level street. Like you need to twist the throttle a bunch more.

Brand new carb. Like 2 weeks old.

However, the service manual stated the CDI would cause this exact issue.



So I ordered the exact thing that alleyoop got in one of these threads.



I'm hoping for same results. Happiness. I do have a DC CDI. Tested by turning key to on, then test light on the 2 pin plug. There is only one wire. It turns on as soon as you turn key to on position. Alleyoop stated that means DC CDI.

[seanstr]

First part will be the Malossi variator today. Won't make a big difference.

Then waiting for 112 jet, performance CDI, THEN, ....!!!😂🤔
Do one change and check results.

[seanstr]

I have the koso installed. I really liked the way the belt rides on the new variator. Test drive on the way to and from work.

Do one change and check results.

[seanstr]

Fun thing, I tried out the adjustable CDI. It's crap. I finally the it away. Wouldn't even allow scooter to start.

Do one change and check results.

Edit, by crap I mean it used to at least allow the scooter to run.

[seanstr]

Aug 25, 2014 14:33:49 GMT -6 rks said:

seanstr said "So, this is my question? Can a minor exhaust leak that is undetectable with the ear cause bad mileage?"

Answer: No

If you are only averaging 60 mpg, on many, many consecutive tank fills, and you are sure you are not loosing any to leaks or vandals....then you must be using it.
Do you know what your original variator weights were? I'm still confused by your statement about what you have now....13gr...14gr....rollers...sliders
Have you checked brake temps after driving scooter...is one dragging a bit...(don't get burned when doing this)
Have you done anything to the clutch? Cleaned out the belt dust...checked pads for glazing....maybe it's slipping some
Do you have a tach installed?.....It would tell you if the rpm's at your normal cruise speed have increased.

Still say pull the spark plug first...if it is covered with cartbon....it's getting too much fuel

Read this thread:

scooterdoc.proboards.com/thread/10488/long-ngk-c7hsa-last

I'm still having this problem, so in reading this over again.

I do not know what weights the rollers where.

As for the 13 gram & 14 gram rollers and sliders, I mixed 13 gram sliders with 14 gram rollers, at least that's what I still have. But what I truly remember was that I mixed 14 gram rollers with 11 gram sliders.

I have a lazer temp gauge and I could check my brake temps this way. What kinds of temperatures am I expecting if they are functioning normally?

The rest have been answered elsewhere.


Do one change and check results.

[seanstr]

The drive in to work was ok, didn't seem any smoother yet but I am not pushing it. Just getting to work. I did try to go faster than 45mph but no good.

Hoping the CDI is the problem and the scooter works great after this.

Do one change and check results.

[seanstr]

The 835 belt still send too long. But I have done some measurements and it's still not the 799 but is closer to 818 to 824, so I ordered something. With luck, anyway

Do one change and check results.

[seanstr]

I reinstalled the OEM drive face variator outer and inner. Using the 13 gram sliders and the OEM belt 799 x 19 x 28 and the "1st gear" is still missing of course but everything else is great up to 40 to 45 mph. Just kind of levels off on going faster. I did get to go faster on a slight down hill. I got up to 47 mph or so, Yeah!, and it was cold, 37 degrees so I'll take it.

The size of the belt I ordered was an 818 x 19 x 28. so other than the length the rest is the same.

I truly hope the CDI coming fixes the MPG and MPH issue cause I'm at a loss as to what else to check.



Do one change and check results.

[seanstr]

Auto choke broke. 4th one. Ordered a new one but when this one goes I'm getting manual setup.

The bearings in driven pulley are worn. I get to replace them too, yeah. Got to re grease it all. But I have 11350 miles so might be time.

Do one change and check results.

[seanstr]

Oh!
The drive home with the OEM parts was pretty cool except the auto choke not working. 1st gear still missing but past that zoom! At least until 45mph.
Do one change and check results.

[seanstr]

My CDI and #112 jet should be arriving tomorrow 😁. Can't wait. Especially the CDI.

Do one change and check results.