Brakes locking up.

[eyeguy]

Today I finally got my TV on the road for the first time. I was cruising at about 55 mph when the back brake locked up. I wasn't sure what happend at first. I thought the engine locked first. Stopped and restarted the scooter all was fine. Road for a while with no issues at slower speeds. Then again while running wide open same thing happens. Rear wheel locks and slows scooter down. Pulled over and started again. Only happens when running wide open. Any thoughts.
Thanks
Eyeguy

[rossclark]

Are you sure it's the brakes? Did it roll with the clutch in?

Anyway what ever it is sounds fecking dangerous and you were very lucky.

[Rich Oswald]

Heat seizure??

[eyeguy]

yes it did roll with the clutch in now that I think about it.

[rossclark]

Seizure then.

[eyeguy]

Thanks thats what it sounds like. Should I send engine off, or how do I check some of those things. I pretty handy but have no clue where or how to start.

Thanks

[rossclark]

If you're handy with the spanners then get yourself a copy of sticky's spanner's manual.

It is the best workshop manual for Lambretta s1 - 3 models.

It will tell you how to check the cylinder / piston / ring clearances, the timing, carburation etc.

If you've suffered a minor heat seize a bit of wet and dry might see you right, clean the piston and barrel up and check the tolerances.

Is the engine newly rebuilt? If so it should be carefully run in for a bit, maybe as much as a 1000 miles, running it at full chat on WOT is a recipe for a seize.

What is the engine spec?

[peejay]

sounds like you need a bit of assistance with the finer points of running a lammie and what to look out for while riding. i think you've had a lucky escape so far.
have to agree with rossclark about the seizure.
probably a good idea to check top end to see what damage you have done before riding again.

[eyeguy]

Yes I do need some break in time myself learning the Lammie. hopefully I didn't ruin anything yet.. I will not ride again until I check things out. Not sure of the specs other than a 175 series3 engine. Don't think it was rebuilt, but I will check with the seller. The spedo shows about 5500 miles.Do you think it's time for a rebuild??? Thanks for all the input. I will order the book.

You guys don't go anywhere cause I am sure I will need advise!! It will be a while before the book makes it and I have time to tear apart.
Thanks for the help thus far

eyeguy

[hullygully]

get in contact with the seller regards the mileage the top ends done
you are using the correct oil/petrol ratios aren't you?
what colour's the spark plug?
try not wringing the throttles neck for a while

[eyeguy]

Hi Hullygully, I am assuming when you say dont wring the throttle you mean slow down. If I do that the scooter has no problem. Its only when wide open for about 2 min then it locks up. I am using non ethonol gas at a 33/1 ratio. The spark plug is not black. not sure I know how to read one.. i would say it looks clean. when you say the top end is done do you mean the head has blown? It still kicks over and starts. Sorry I don't understand shop talk.

Any help is appreciated,
eyeguy

[peejay]

hi eyeguy
if you have an original cast iron barrel then it certainly needs much more running in even if the jetting is correct. if you have a modern ali kit and the jetting is somewhere near correct it is much more forgiving on large throttle openings and will probably give you an advance warning that all is not well by hessitating as you try to ride at any significant speed.
getting the full engine spec from the builder/ last owner will give you a starting point.

PeeJay

[eyeguy]

Hi PeeJay, Can't get the info if the engine was rebuilt or not. However I did notice that the mixture screw was only turned out about 1.5 turns. From what I gathered it needs to be about 2.5. I did this and so far all is good. I am going to treat it as if it needs breaking in. I viewed the spark plug after a good ride and it seemed good. So hopefully it will be fine. I would like to upgrade the engine. I saw the SS200 cylinder kit. You think that's an overkill?

Later
eyeguy

[maz]

Hi mate welcome to the world of vintage scootering.

Before you run you must first learn to walk.............. find out what your initial problems were............. like one or two have said buy a copy of ' sticky's spanner's manual ' and learn the differences between engines and what you can and can not do with them.

like most people have said........... it really does sound like you have experienced a piston siezure and you have most likely caused some damage to the piston and rings and therefore you need to take the head, barrell and piston off and have a look.

One massive word of warning, be very careful about throwing money at a problem you are not 100% sure what has been caused by......... this can be a very expensive game !

You use some strange terminology............ where you based mate ? where do you live ?

[eyeguy]

No it's you that uses strange terminology . Just kidding!!! I am in the good ole USA.Southern part of Illinois. I'll be honest, I was going to join the US forum but didn't get a very good welcome. Also some very rude responses. So here I am with you guy's. I think I found the problem with the siezure. My fule mixing needle was only turned out 1 turn. After adjusting it about 2.5 turns it has not had an issue. I will say I am backing off the speed until I have put at lest a 1000 miles on it. I was told it was a soft siezure and hopefuly no damage done. Anyway rode all this weekend and all is good.

I would just like to be able to run a little faster so the cars behind me don't get to angry.

Thanks for your advice. It really means a lot. I am willing to give it some time to learn. I do have Sticky's book.

Later Mate
eyeguy

[hullygully]

you'll allways get a response on here, sometimes not favourable but as long as you give our written regional accents a go its allways well meant, well almost keep the faith

[eyeguy]

Thanks HulluGully, I feel right at home here.

eyeguy

[maz]

The particular terminology that drew my attention was " ethonol gas " which made me think you were maybe from the good ole US of A........... UK peps would say petrol or unleaded........ among other things.

One thing about your engine you do need to find out is if it's a TV175............ does it have the standard TV175 crank or has it been replaced over the years ? Generally speaking the TV175 crank has a different ' con rod ' to other series 3 engines....... it's length being longer therefore different pistons......... which means if you want to put a modern ' kit ' on you more than likely will need to change the crankshaft........ again have a good read of ' Sticky's manual '.

[eyeguy]

Thanks for the tip. Learning more all the time. Scooter is running fine still. Leaving well enough alone for now. I am searching how to tune the carb. Any thoughts?

eyeguy

[Scooterlam]

Upping your main jet, would be a step inthe right direction.
there are loads of exploded views online to help you locate it.