200 colt

[Paul_Linden]

C11G and C12 have a different bore and stroke to a Colt, so it's not going to flop straight in. I don't remember if the studs for the barrel and head have the same spacing - I'd need to check the old Colt and C12 barrels I have in the shed.
I think a whole C11G or C12 engine (cases, barrel and head) will fit straight in.
The rust damage to the bore in picture 3 - it might not be critical to remove it all with a rebore if what's left is only above the rings at TDC and is not deep.
Draganfly sell second hand Colt barrels for £35-ish, which are already first or second oversize.

[bsmart]

thanks for the tech info Paul , very helpfull i only asked as there was a barrel and piston on ebay the other day , i took the barrel to a local engineering cop and after alot of deeply inhaled breaths thro the teeth he recond that it was to far gone , if it was a standard he rekond we could save it but as its at +0.5 its to far gone . so i got hold of a brand new barrel and pistons for £80 ish delivered , chances are something may have popped up on ebay but i fugured if i get that then its only check the bottom , oil pump and make sure everything is within useable limits . i now already that the stator is gassed but as this is a secondary project and i have one of the main parts sorted ill keep my eyes on ebay .

cheers again

[bsmart]

Paul , sorry but im looking to pick your brain , im getting to the point of realesing everything but the advance and retart mech requires to come off , on your thread you say that a 7.5 mm x 80 mm rod and that part i have done but im a lad of the metric system , can you tell me what bolt i require to go into the intermal threads ?

cheers
blair

ps it must have been a comon fix to use a bit of wire instead of a circlip as mine was the same as yours

[bsmart]

been to work today and managed to get the advance / retard unit off , makes a bit more sense now its in bits . not sure if its serviceable but its now sat in a bath of wd40 . since this is a side project i have set it all up on the side bench and also manage to print off a large bow out of the engine for referance . now to get that nut off the other end of the crank shaft



set up for being dismantled



progress . slow but theres no rush

this photo was ment to be on my last post , showing the wire instead of the circlip modification

[Paul_Linden]

I guess it's academic now, but the thread is 5/16" BSW (16 TPI). You can always send me a PM for a quicker reply.

[bsmart]

hi Paul not a problem , i was really being lazy if im honest . i have a fastners company next to my work but they sometimes struggle with anything that not metric .

in the future if i need to pick your brain ill send a pm

cheers

[bsmart]

little up date , had a look at the small gear wheel at the and of the crank shaft but realised quite quickly that A. i did not have a puller small enough and B. that i would have to remove the oil pump before i could get ( A ) on once i have found one .
to get the pin at the top of the pump drive gear out i used the bolt from the advance retard unit as it fits straight in , im a metric man and most of my nuts and bolts are metric along with my spanners but i do have a small selection that fit . the washer that sit infront of the pin was missing , im no Hercule Poirot but i can tell when someone has been " fixing " and engine so im going to guess that at somestage when someone cracked the casing off they never notice the washer so it never whent back in .
the oilpump bolts came out ok and didnt look like they had been interfeared with before , there was some sludge but i shall crack open the pump at a later date .
the lock tab that held the crank shaft nut on was well bent out of shape and the nut itself was pretty badly rounded but i managed to get it off so that leave me to find a puller to fit it and try to remove the gear .....going by Pauls thread i may need a little heat as well

[bsmart]

its a bit cold up here so just spending an hour in the garage is enough , disasembled the oil pump , it would turn but only with pliers not fingers . after given it a good clean to get rid of the sludge it turned no problem . to test it i stuck it in a spray can top filled with oil and turned it , sure enough it worked so thats were it will stay for the time being







next on the 1 hour hit list is the advance/retard unit

[bsmart]

well i think my lack of knowledge may come into this engine rebuild a few times and the advance retard unit would be one of the hurdles , when i removed it i really didnt have any idea of how this was supose to work , i knew it was about throwing weights out at high revs but couldnt work out how this was suposed to happen , but i asked some members of another site and they explained that there should have been 2 spring to retract to weights but the unit i have has been "modified" to remian closed

apperently this was quite a comon mod to make back in the day , so it may be just a case of finding springs with the correct springyness or try and source a new unit








on another note when i got the bike there were some spare engine parts , my bike had the head removed and push rods were missing , going to guess that someone bought a spare engine to get parts from.

so i have a couple of questions to ask that you guys may be able to help with

what length should the pushrods be ?
can anyone identify the crank case on the right ?
does anyone have a wiring diagram for a colt ?





from what i can tell i may be just missing a barrel , oil pump , stator , advance retard unit and i would have a spare engine

[Paul_Linden]

Hi Blair,

Well it looks like you are getting well stuck in to this Colt.

The cases on the right are from a BSA C10 or C11. There is a mounting at the rear for a dynamo which the Colt cases don't have. The engine number will have C10 or C11 in it somewhere (like XC11.455).

I can email you a Colt wiring diagram - send me your email address by PM.

Colt alloy push rods are both the same length: 8" 5/8.

Paul