kickstart kickback

[maggo1974]

hi guys..need bit of help..i will tell you the story and hope you can help.my best mate built up a lambretta from scratch and it has an engine he bought of someone on the famous ebay.(the engine is a rb250 without reeds.and a 35mm mikuni carb) he completed scoot with powder coat paint (r1 blue with metal flake in it ) front and rear disc brake etc..any way he sadly passed away 2 and a half years ago and left me the scoot.i have only just got it cos his partner is only just gettig around to sorting things.i changed petrol,cleaned carb cleaned plug.while plug out i pushed down on kickstart to check free and all ok,put plug in and tried to kick her off.well after a while it fired but not run.after that i tried again and the kickstart started to kickback.this didnt happen when he had it cos we did a couple of rallys together.(it was a c**t to kick off cos of compression).would like to get her up and running and finish off some of the bits and bobs he didnt get done.would be gratefull for any advise and help..i dont live far from the foxhat boys but would still like your views please..cheers...les.

[Muppet]

Bigger boots

[camel]

firstly how do you mean without reeds?are they fitted now?
in my view a tough lammy to kick over is not always related to top end compression,think about it your turning the first gear cog,chain and front sprocket round as well as the crank etc so it can be related to what box and sprocket combo you have
a tall first gear will seem like high compression(which of course you may have aswell)

[coaster]

[quote="camel"]....think about it your turning the first gear cog,chain and front sprocket round as well as the crank etc so it can be related to what box and sprocket combo you havea tall first gear will seem like high compression[quote]

I know where your coming from but the kickstart only operates on the teeth on the side of 1st gear so the number of teeth make no different. BUT the size of front and rear sprockets WOULD make a difference. I have a similar issue with the TS1 I've recently put together, it take a very determined kick to start it as it will kick back with anything less. TBH, I am thinking it is probably timing and will be re-strobing when I get time.

[bristolmod]

timing could be over advanced.............

You kick it over and it fires too soon- the ignition explosion trys to force the piston back down before it travels over TDC.

In extreme cases the engine will fire and run backwards ( I kid you not!).

Check timing.

Chris

[maggo1974]

cheers guys..it does not have reeds fited..i dont know what box and sprockets are fitted yet as i cant remember what my mate said.it was 2 and half years ago,will have to check.will also get timing checked.

[Yanker]

It'll probably be a Rapido 250 then (without reeds). If he did it properly then it will need a hefty kick. You are not trying to start it on the stand are you? Get it off the stand, lean it over and crank it in a manly fashion. You will want boots and not trainers! All Bristolmod's advice is highly accurate and relevant.

[maggo1974]

thanks yanker.will try off stand.i am vertically challenged tho..lol

[Yanker]

You'll need some 'girth' then, or some vertically challenged assistants with pulleys...if there is a circus in town lol

[maggo1974]

lol.yanker.