Blata rep engine rebuild two stroke

yamaha4life

looking for advice on my minimoto, blata rep two stroke watercooled engine, i cleaned the carb, checked for spark and refitted it. Put some fresh fuel in and tryed to start it, the pull start is broken so used a cordless drill to swing engine.

on the initial go it gave a very slight try to start for a second, after that nothing pulled plug was dryish, thought it wasnt getting fuel but then saw carb bowl was weaping so must be getting some, i put a drop in down the throat of carb nothing happend, tryed plug hole aswell nothing.

the engine would appear to have compression but dont think theres alot compared to my cag engine. The cag had a good bit more resistance.

to add to the confusion the bottom radiator hose filled up with fuel so my guess would be theres a problem think it might have been ran without water by previous owner, so probably overheated. I suspect the headgasket is gone.

im new these little engines so could someone break down what i will need for a rebuild and where to get parts!

It looks a bit like i will have to make gaskets and things would rather a kit and fit it though.

yamaha4life

I tore down the last night, There didn't appear to be too much play in piston at tdc but small engine so yeah i might be wrong.

Questions
What do i use to seal the top cap a standard rubber o-ring? Theres two seals. They look like rubber o rings!

the barrel doesnt look too bad but im not 100% sure but piston definitely has wear and ring on exhaust side check pic!

where can i get a new piston and ring? New Barrell if needed? The piston is 37mm single ringed.

​The head gasket was gone on exhaust side can i use any gasket paper the squashed gasket measured 1.2mm so i guess it would have been a lil thicker?

do i need to split the casing to change waterpump bearing?

thats all i can think of right now any information would be great

Hotblack Desiato

Was probably run without 2-stroke oil. What's the big end like (can you rock the con rod side to side at all?) and depending on how long that went on for the main bearings might be gone too. A picture of the inside of the exhaust side of the barrel would be good.

Is the top of the barrel and cylinder head flat, no cracks etc? A new gasket might be all you need.

yamaha4life

Hi thanks for your reply the big end has slight sude to side no up and down, my other engine has the same so i think its ok. Here are some more pictures. I have deglazed the barrell it looks alot better but i have no pictures. With the piston and ring fitted there is not much lateral movement near tdc, i can get a repair kit without the barrel much much easier than with :-(

Hotblack Desiato

Doesn't look too bad. You might as well try a new piston, rings and head gasket and see how it goes.

yamaha4life

It looks a bit worse in person the plating is coming off the wall in places,after scotching the walls alot of the marks came out and the cross hatching returned only thing has me worried is the chipped plating.

I emailed cork engine center about it but they said it looks too damaged to reuse with a std piston? Im not an expert but from what i gather its only the plating thats damaged so could it not be replated and used again?

Either way i think if i dont find a barrel by the end of the week ill buy the repair kit minus the barrel and put it together and see what happens, maybe some lourdes water in the rad for luck!

yamaha4life

been a while waiting for parts from china for my blata rep but most have come now and i want to fire up this little cnut!

But right now i have a small problem, when i fill up my coolant tank, it seems to just come out the pipe on the radiator overflow im guessing, if the bike is anything but level or tipped to the opposite side of said pipe, if i tip it in the direction of the pipe it leaves coolant out! This is while its not running btw so i can only assume while running the waterpump might push more out.

why is this happening? Should this pipe be capped? I stuck a bolt in in for now to stop it marking its territory in my house

Ive tried leaving some air out of the bleed screw on the top hose but didnt change,

what do i do about this?

Im still going to try start the beast later, heres a picture of the radiator setup