Engine replacement after CCT failure....

[Brokentechie]

Hi guys, new here and I hope you don't mind me diving in with a Q before I introduce myself.

I have a customer with a very poorly VTR - front CCT failed and it currently has 1 very bent inlet and 1 completely broken inlet valve!

I have sourced a new engine for a great price, however his is an import (clocks are manual and in km) whereas replacement is a UK bike (digi odometer).

Both about same year - his R reg, new one T reg - Q is: Is there anything that I need to know to replace the import engine for the UK one?

They are both carb model, and the engine swap is likely to be the cheapest option for him (with the snapped valve I think he looking and new cam, valves, valve guides, cylinder and poss cylinder head and piston+rings) so are they compatible?

Many thanks


BT

[AMCQ46]

Quick answer is yes.

Newer bike had a bigger tank, a smaller airbox and the new clocks, almost everything else is same.

only area I am not sure of is if the speedo pulse generator is different, but you will be able to swap those if it is a problem.

Put the other engine on here to see if anyone needs bits off it or the rear cyl head.

Also dont let him have it back till you fix the CCT's either manual or the stopper mod which you will fing instructions for in teh workshop section.

[gilson]

Or you could just swap the head over. You wouldn't even have to take the engine out of the frame IIRC. Careful of timing 180 degrees out either...sorry if I'm teaching you to suck eggs...

[Brokentechie]

Or you could just swap the head over. You wouldn't even have to take the engine out of the frame IIRC. Careful of timing 180 degrees out either...sorry if I'm teaching you to suck eggs...

Not at all, however like I said one of the inlet valves has snapped off completely so I fear there's bore damage, head damage and piston damage too - I could swap the whole thing, but I'd be wary about swapping the whole front cylinder to the existing engine - I have huge hands and as we all know space is quite limited on the front pot lol

Thanks for the replies chaps

BT

[tony.mon]

You can't swap the cylinder, they're cast in with the crankcase.
So if there is wear on the cyl wall then it's the engine swap.
You can re-sleeve, but that's still an engine rebuild to split the cases.
TBH, with the forces generated on the big end, little end and mains when the piston's trying to punch the snapped-off valve through the head, you won't get away with anything short of a complete engine rebuild, or a replacement.
Lastly, check the cam to head and cam to top clamp clearances with Plastigauge, as per the Haynes manual.
The forces on the cam with a snapped valve is often enough to have created excess wear and the cam will not last long afterwards.
If knackered, new heads, cams, clamps.

You'll need the special socket for both sizes of engine mounting bolts, and they often seize in place.
I find it's easier to chock the engine, then lift the whole frame off the top, takes two people but easier.
If you have the replacement lump ready to go standing next to it, you can just drop them frame over the next engine.

[bazza696]

Hi guys, new here and I hope you don't mind me diving in with a Q before I introduce myself.

I have a customer with a very poorly VTR - front CCT failed and it currently has 1 very bent inlet and 1 completely broken inlet valve!

I have sourced a new engine for a great price, however his is an import (clocks are manual and in km) whereas replacement is a UK bike (digi odometer).

Both about same year - his R reg, new one T reg - Q is: Is there anything that I need to know to replace the import engine for the UK one?

They are both carb model, and the engine swap is likely to be the cheapest option for him (with the snapped valve I think he looking and new cam, valves, valve guides, cylinder and poss cylinder head and piston+rings) so are they compatible?

Many thanks


BT

It would be easier to take the top of the engine off and replace the valves, Tony done one in hours and a lot cheaper than swapping an engine out....if you can get it out without cutting the old engine out....

[Brokentechie]

Thanks for all the replies guys (and gals if there are any) - next problem, engine swap done, however the starter had chewed itself inside out so had that done, now when starting there is a god-awful amount of clattering and noise on the starter, and bike is difficult to start.

Turned over by hand loads with no sticky spots so happy that nothing in the engine is colliding, so could it be the starter clutch effort - read another thread about the "sprag" being tits-up, so is it likely to be that?

Also to remove flywheel - drain engine oil etc?

thanks again for all help, mucho appreciated

BT

PS replacement engine was £250 so he got a bargain!

[benny hedges]

could be the sprag bearing.... maybe the one on your old engine is ok?
they can fail if the bike has been kicking back when started on a low charge, ie fkt battery or duff r/r.

you don't need to drain the oil, just lean the bike over with handlebar on full left lock against a wall on the right.
a bit of oil will come out as there will be some inside the casing.
get a new timing cover gasket tho as it will come off fkt! (silvers about £7)
tie the casing up toward the seat to avoid damaging the stator wiring, or disconnect it at the plug.
to get the flywheel off you will need a m22 fine bolt (£13 off ebay) - don't try getting it off using the 1st gear & back brake thing as it won't work and you will succeed in creeping the bike forward and knocking it over (don't ask!)

use a big adjustable or plugging spanner on the flats of the flywheel, but watch you dont damage the edge with the timing marks or the inside that runs round the stator as it is very thin metal plate ;)
have fun getting the 17mm bolt out of the end lol - it's a normal rt hand thread btw as the engine turns anticlockwise.

*oh, and as always, threadlocking compound when it goes back together!