This is my first topic, I am going to need a lot of help, as its been over forty years since I even rode a scoot. Anyway, bought a beautiful 1963 li150, rode it , checked out etc. New plugs oil change did everything to make sure it was ok. First reasonable length ride, it seized on a throttling back on a bend. Clutch in stopped. Wouldn't kick, locked and wouldn't roll in gear. Trailer home. I borescoped it and could see little head damage from some debris but no major heat damage. Thought maybe I caught a ring, detonation maybe. Anyway, I stripped it down and the cylinder slid straight off, one longtitudinal scratch but otherwise OK. The conrod though was seized on the crank. I sprayed a little pb blaster, jammed the flywheel and gave it a little tug and it came free. I am going to strip it down and go from there, but any advice from you guys would be great. I would like to keep it original if possible as it is a correct number Italian bike with perfect bodywork etc. Here is a video of the crank and a little chip you can see out of the case, what is your diagnosis so far. I was thinking maybe failed bearing and the piston damage from thepeices.
https://www.youtube.com/watch?v=ra8sybeLUv0
Li150 seized. What do you think.
-
dragoonpvw
- registered user
- Posts: 36
- Joined: Thu Oct 25, 2018 5:02 am
- Main scooter: Lambretta Li 150
- Contact:
-
dragoonpvw
- registered user
- Posts: 36
- Joined: Thu Oct 25, 2018 5:02 am
- Main scooter: Lambretta Li 150
- Contact:
One other thing, is this the right place to post this to get ongoing help with the strip and rebuild.
You say the conrod was jammed, but in the video it's far from jammed.
Looks to me like the big-end bearing has failed. You need to strip the bottom end right out in case there is debris in there. Then I suggest a new crank!
We can't see the piston/barrel but from your description they may well be re-useable.
Just one thing; You did mix some 2-stroke oil, at least 3% (fully synthetic) into the petrol?
Looks to me like the big-end bearing has failed. You need to strip the bottom end right out in case there is debris in there. Then I suggest a new crank!
We can't see the piston/barrel but from your description they may well be re-useable.
Just one thing; You did mix some 2-stroke oil, at least 3% (fully synthetic) into the petrol?
-
Doom Patrol
- registered user
- Posts: 1823
- Joined: Wed Jan 07, 2009 5:03 pm
- Main scooter: Jet 200
- Location: Second star on the right and straight on till morning
- Contact:
Don't get hung up on fully synth oil. You really don't need it for a standard 150.
-
Scooterdude
- registered user
- Posts: 796
- Joined: Sat May 28, 2016 4:51 pm
- Main scooter: Lambretta LI 125 S3
- Location: Skaville
- Contact:
My guess is if haven’t lost a ring causing the damage and a piece subsequently getting jammed in your big end, the bearing itself has simply failed through age/wear.
As its a standard engine I’d suggest you strip it and get someone like AF Rayspeed to fit a new rod and bearing kit, and while you’re at it get them to rebore the cylinder and supply a new piston kit.
As above no need for fancy oils, something cheap like Rockoil Groundsman is quite sufficient.
As its a standard engine I’d suggest you strip it and get someone like AF Rayspeed to fit a new rod and bearing kit, and while you’re at it get them to rebore the cylinder and supply a new piston kit.
As above no need for fancy oils, something cheap like Rockoil Groundsman is quite sufficient.
-
dragoonpvw
- registered user
- Posts: 36
- Joined: Thu Oct 25, 2018 5:02 am
- Main scooter: Lambretta Li 150
- Contact:
As I said, it was jammed but I freed it. The guy I bought it from gave me his Castor 927, but he gave me his mixing instructions and a two stroke syringe.(mix master) to get the mix, two shots to a mark that he had made to one US gallon. When I checked with my own jug he was mixing just over 2 percent, he must have miscalculated and it should have been four shots.. I mixed 4% in the fuel I used. I think the main has gone and that caused damage.
There are no local rebuilders here in Florida, so this old Leeds lad is going it alone.
My main problem now is, do I need special tools to get the crank out. I would rather not mess with removing the clutch if I can help it. Just remove the front sprocket and the flywheel and mag housing. There is a bgm pro stator with ignition fitted so that is where I am.
Then probably a new crank and bearings , if necessary a cylinder and piston.
There are no local rebuilders here in Florida, so this old Leeds lad is going it alone.
My main problem now is, do I need special tools to get the crank out. I would rather not mess with removing the clutch if I can help it. Just remove the front sprocket and the flywheel and mag housing. There is a bgm pro stator with ignition fitted so that is where I am.
Then probably a new crank and bearings , if necessary a cylinder and piston.
-
Warkton Tornado No.1
- registered user
- Posts: 296
- Joined: Mon Oct 17, 2011 6:16 pm
- Main scooter: Lambretta SX200
- Contact:
Given the age of the engine, it has done very well & needs some (probably overdue) TLC.
A habit many have (especially after not riding two strokes with pre-mixed fuel) is to throttle off as you tend to on a four stroke, which means less oil. Worst still is the idea that low revs & more oil help the running in period, but that is only worth mentioning as it's likely you will need new rings.
Don’t worry about the crankcase chip as you can tidy that with a file after stripping out the crankshaft.
If I were you, I’d get the existing crankshaft pressed apart & a new big end bearing fitted if the bearing surfaces of the pin & rod bore clean up. They probably won’t(!) so a conrod kit might be in order. In which case, due to the likely cost, a good, second-hand crankshaft may do or, as many might advise you, a SIL GP crankshaft that has been rebuilt using a good big end bearing. That will require you to modify the flywheel but GP flywheel centres are available that can be put in place of your existing, smaller taper flywheel centre. Check the bearings which might be fine, but the seals should be replaced. Nitrile seals will be more than good enough. (Despite the use of ethanol in fuel, if you Google the subject, you can find research by unbiased Organisations that will assure you that we don't yet need to remove all the seals from our scooters, motorbikes, cars & lorries just yet....
)
As for the bore & piston, a light hone might suffice with new rings.
Rebuild should be methodical & that may incur some expense, though you may be lucky. Personally, I always endeavour for the best squish, the optimum being 1.0 mm & NEVER use a head gasket. Hopefully, you can then fiddle with base gasket thicknesses (even thin alloy types are available now) to get the optimum piston to head clearance….
As for the subject of oil that has been touched upon, again, this is personal, but Exol are the only manufacturer that I am aware of that makes air-cooled specific (Optima) fully synthetic two stroke oil. I can buy it @ £15 cash for five litres. In a tuned long stroke Rapido 240 engine, it performs very well @ 2%, which makes for incredible economy IMHO.
Lastly, if the original engine ran well on points, my belief is that they are probably more reliable than the current Indian electronics. The mass of correspondence on both significant Forums more than validates my reasoning, yet they are supposedly selected for ‘reliability’
I hope that you can enjoy the rebuild!
A habit many have (especially after not riding two strokes with pre-mixed fuel) is to throttle off as you tend to on a four stroke, which means less oil. Worst still is the idea that low revs & more oil help the running in period, but that is only worth mentioning as it's likely you will need new rings.
Don’t worry about the crankcase chip as you can tidy that with a file after stripping out the crankshaft.
If I were you, I’d get the existing crankshaft pressed apart & a new big end bearing fitted if the bearing surfaces of the pin & rod bore clean up. They probably won’t(!) so a conrod kit might be in order. In which case, due to the likely cost, a good, second-hand crankshaft may do or, as many might advise you, a SIL GP crankshaft that has been rebuilt using a good big end bearing. That will require you to modify the flywheel but GP flywheel centres are available that can be put in place of your existing, smaller taper flywheel centre. Check the bearings which might be fine, but the seals should be replaced. Nitrile seals will be more than good enough. (Despite the use of ethanol in fuel, if you Google the subject, you can find research by unbiased Organisations that will assure you that we don't yet need to remove all the seals from our scooters, motorbikes, cars & lorries just yet....
)As for the bore & piston, a light hone might suffice with new rings.
Rebuild should be methodical & that may incur some expense, though you may be lucky. Personally, I always endeavour for the best squish, the optimum being 1.0 mm & NEVER use a head gasket. Hopefully, you can then fiddle with base gasket thicknesses (even thin alloy types are available now) to get the optimum piston to head clearance….
As for the subject of oil that has been touched upon, again, this is personal, but Exol are the only manufacturer that I am aware of that makes air-cooled specific (Optima) fully synthetic two stroke oil. I can buy it @ £15 cash for five litres. In a tuned long stroke Rapido 240 engine, it performs very well @ 2%, which makes for incredible economy IMHO.
Lastly, if the original engine ran well on points, my belief is that they are probably more reliable than the current Indian electronics. The mass of correspondence on both significant Forums more than validates my reasoning, yet they are supposedly selected for ‘reliability’
I hope that you can enjoy the rebuild!
-
Warkton Tornado No.1
- registered user
- Posts: 296
- Joined: Mon Oct 17, 2011 6:16 pm
- Main scooter: Lambretta SX200
- Contact:
Ooops!dragoonpvw wrote: ↑Tue Oct 30, 2018 5:05 pm As I said, it was jammed but I freed it. The guy I bought it from gave me his Castor 927, but he gave me his mixing instructions and a two stroke syringe.(mix master) to get the mix, two shots to a mark that he had made to one US gallon. When I checked with my own jug he was mixing just over 2 percent, he must have miscalculated and it should have been four shots.. I mixed 4% in the fuel I used. I think the main has gone and that caused damage.
There are no local rebuilders here in Florida, so this old Leeds lad is going it alone.
My main problem now is, do I need special tools to get the crank out. I would rather not mess with removing the clutch if I can help it. Just remove the front sprocket and the flywheel and mag housing. There is a bgm pro stator with ignition fitted so that is where I am.
Then probably a new crank and bearings , if necessary a cylinder and piston.
You must have Posted that as I was typing my own response.
(The ignition you have should be good, but my reasoning about poor quality electronic ignitions remains valid)
You need a good manual (such as Sticky's) & a few tools such as flywheel holder, flywheel puller & possibly three legged honing kit.
Early Christmas presents, I would have thought......
My point was not about "getting hung up" on any particular oil. It was; did he remember to put ANY in the fuel (which it seems he did)Doom Patrol wrote: ↑Tue Oct 30, 2018 9:39 am Don't get hung up on fully synth oil. You really don't need it for a standard 150.
dragoonpvw
Sadly on forums such as this, when someone offers advice, someone else comes along and contradicts it.
It really doesn't help when someone such as yourself is seeking assistance.
In the end you'll have to read it all and decide for yourself which advice to take.
P.S. Fitting a new rod/bearing to an old crank is, in my opinion, a monumental waste of time, effort and money. There are many new cranks available that would do the job. Mazuchelli and Mec-Eur spring to mind.
Yes, I have just contradicted a previous poster. So you'll have to make your own mind up.
Sadly on forums such as this, when someone offers advice, someone else comes along and contradicts it.
It really doesn't help when someone such as yourself is seeking assistance.
In the end you'll have to read it all and decide for yourself which advice to take.
P.S. Fitting a new rod/bearing to an old crank is, in my opinion, a monumental waste of time, effort and money. There are many new cranks available that would do the job. Mazuchelli and Mec-Eur spring to mind.
Yes, I have just contradicted a previous poster. So you'll have to make your own mind up.