Do I Have A Ty80 Or 50?

[steve1979]

Hi, I am in the process of rebuilding a little TY for my son, I got it in a sorry state, the person I got it from told me it was an 80 so that's what Ive been going on. I've had the frame, swing arm etc shotblasted and now it's all repainted. I was cleaning the engine getting it ready for painting when I found "553" with "49cc" stamped underneath the fins on the cylinder. When I put in the frame number on the Internet it tells me she's a 1975 TY80. Is the 49cc stamp telling me it's a Ty50 or does the 49cc relate to something else. Thanks for any help.

[steve1979]

Thanks oni nou, it might end up coming to that eventually. I sent off the engine serial number through yambits, typically though the first 3 digits are readable as are the last 5 but the 6th digit in the line has got damaged sometime in the past making it unreadable. The frame does appear to have 80 rear shocks etc but the engine seems to be hinting at its a 50 with the shape of the barrel going on images on the Internet the 80 looks different. It will be whatever it is. I'm not sure how a 50 performs against an 80 but I guess we will find out once it's finished.

I'm thinking maybe at some point someone has put a ty50 into a ty80 frame and perhaps made one bike out of two.

[steve1979]

Hi, I took your sizes and while the engine is on the bench and the carb and reed block are off, I measured with a piece of firm stainless wire the bore size. I put the piston to tdc and I was able to measure underneath the piston from the front of the cylinder to the back of the inlet and I got 41mm so I guess I have a TY 50 engine in a ty80 frame. Im thinking once he gets bigger and perhaps the 50 gets too underpowered for him I can put on one of those big bore kits perhaps. Maybe the 50 will be ample for a long time? How does the 50 fare against the 80?

[steve1979]

Cool, I had a little look at some YouTube videos of guys on there TY 50s and they seem to have a lot of pep with them. He follows me around on his 70cc quad while I'm on my gas gas 250 txt pro but he can only go over very small bumps etc so if he can get the hang of the TY then we can venture out to more places. He's only 5 so it will be probably next summer before he can start having a shot.

I'll check out the big bore kits, they may be a nice little upgrade once he's older.

Cheers

[steve1979]

Well I now know the exact engine and frame. She's a 1975 TY80 frame and a 1978 DT50M engine. I got this information from yambits so now I know. No idea how the gearing will be for hill climbing like oni nou said but I guess it'll be a bit of fun all the same and in the mean time I can keep an eye out for an actuall ty80 engine to put in some day.

[steve1979]

Hi, I'll try a small update of progress with the TY, she's not going to be original especially with the tank. The tank was a mess, full of holes and filler! After silver soldering up the pin holes, resin lining the inside and for belts and braces a full coat of fibreglass all over the outside, it is now bullet proof. I wanted to do something a little different from the standard graphics. this is how she is ATM, still in the progress of making a seat unit, then airbox.

This is how she was when I got her! She was apparently destined for the skip before the fellow before me salvaged her.

I have various pictures of her as I went along. She was never going to be showroom or 100% original but atleast she'll perhaps live on a little longer.

[steve1979]

There was plenty of parts missing and other bits rotten with rust, I think what saved the frame was over her lifetime she has had multiple colour changes and has held the rust at bay from the frame and swingarm. Unfortunately the rims and spokes were bad, I managed to salvage the rims but had to replace both front and back spokes. The front forks were pitted beyond repair so I managed to source a second hand pair that were fairly corrosion free on the stanchions, so stripped and rebuilt with new seals etc and repainted. Exhaust was pretty ropey too but I've welded it up best I can with what metal was left to weld to, it will have to hold until perhaps next year I'll build a complete new system basically copying the original. Anyway I'll not waffle on about what's been rebuilt, replaced etc but I will say, what a fantastic starting little machine, way better than my gas gas. Only snag ATM is the rear shock seems to close to the chain? But all spacers etc are in place. The split link actually touches the spring as it goes past? Any ideas as to why that may be? Unless something is twisted around the frame/swingarm

[suzuki250]

it's looking good  

The only thing I would add is a rear sprocket guard (I saw someone lose some fingers when I was in the schoolboys!)

[steve1979]

Thanks ? Yes a chain guard will be on the to do list, I'll look into that. I'm wondering if I can get something that will cover the chain and also wrap further around the sprocket. I may need to fabricate something, the original chain guards look quite minimal for protection. Don't think the wife will be to happy if I come home with 99% of the boy lol