No power??

[dapper]

Piston's in right way round, isn't it, with arrow pointing to exhaust port??

[muffster]

Yes mate it is!!
After a rebuild, new piston, crank, bearings + seals it's quite smokey and i get an occaisional drop of black oil from the exhaust. I'm hoping the oil seal hasn't gone.

[dapper]

No, quite common as its the additional 2 stroke burning off the piston/small end etc. that was used to slip everything in.

[muffster]

Ah thanks for that.
That puts my mind at rest a bit and hopefully won't have to strip it all back down again!

Cheers.

[Daggs]

Have you sorted this yet?
If not, use the carb settings posted by Bristolmod and I.
Now tell me what gearbox and primary drive you are using.

[djh66]

check the flow rate from that rear exit tap as there have been probs reported

I had a similar problem and it turned out to be the rear exit fast flow tap, letting in air through the fuel pipe, restricting the amount of fuel goiing into the carb. Changed it with CamLam for a standard fast flow, resolved the problem.

[muffster]

No mate not sorted yet.
The gearbox is the original standard gearbox for an LI125.
I tried putting all the original jets back in the carb, although i havnt changed the slide, but it was the same.
I will check out the fuel tap tomorrow and see if it might be letting air in, but it is brand new and it was running ok, thats why i can't understand why its won't run properly now???

[Daggs]

Running a 175 conversion through a 125 gearbox is not ideal, but it should if anything pull along readily.
I read back through t his thread and i'm concerned about how you set the timing.
"30mm before TDC" is that vertical piston movement or 30mm on a timing disc? The best answer is to set the TDC using 'positive stop' and set the timing to 19 degrees BTDC. That's left of TDC as you look at the flywheel.

[muffster]

Daggs, hello mate.
i set the timing up using a spark plug, the positive stop method as per the book. I set it 30mm from TDC, thats what the bloke in the shop told me. I'm not sure what 30mm equates to in degrees done with a disc.
Iv'e been trying to suss it out again today. I even took out the fast flow tap and put the origianal one in but it made it worse. So, fast flow back in and fuel filter removed but still the same, nice tickover but won't run under load.
I will have a look at the timing tomorrow and try set it to 19 deg and see if it makes a difference. But it was running nicely when i set it up to 30mm from TDC. :wtf:
I can't find any air leaks.
Will report back tomorrow

Cheers.

[Muppet]

Divide circumference of flywheel in mm by 360; each single degree will equal (x)mm so how many times does that figure (x)mm go into 30; This will give you a measurement in degrees from your original 30mm timing measurement.

muppet