The kit's listed as being for all the 125s but the combustion chamber volumes are quite a bit different between the models. I'd be surprised if the kit just bolted straight on without some other sort of work as TLrider has pointed out. If you're using the standard TL head on a big bore kit you'll be raising the compression ratio quite a bit unless the piston is dished.
A Honda xl185 barrel will go onto your cases after boring them out (sleeve diameter 69mm), with an ATC 185 (dished) piston it helps to keep the CR down, see the picture below.
It's difficult to lower the CR on the ohc engines as you're restricted by the cam chain length.
This is what TLrider means by cutting into the oil gallery, this is one I did last year. I've since had it welded up but the project has kind of stalled.
1.5mm sleeve thickness is fine, especially for a trials engine. Pete Arnold at PACRE http://www.pacre.co.uk/ won't go lower than 2mm but he's building high spec road race engines that have won championships out of the CB motors.
To be honest, it's easier to just fit an xl185 engine or even better the post '79 xl125 6 speed bottom end with the 185 crank and top end (no casing boring required), but where's the fun in that!?!?
On the CB and XL Hondas the frame no. is on the headstock, maybe it's either been buffed off or under a ton of paint or somewhere else!
Your engine is from a CB125J (the one with the disc front brake, late 70's), externally the same but with different comp. ratio, cam timing, valve sizes, flywheel design and gear ratios.
Relative to the CB, the TL has a low comp dished piston and a head with a small combustion chamber and small inlet / exh valves. This along with different cam timing and a heavier flywheel allows better bottom end plonk without stalling.
On the CB motor, 1st gear is the same as the TL but the other ratios are different, unless someone's put the complete TL 'box in your cases as they are a straight fit (gear clusters, selectors and selector drum). You can fit the TL's 2nd gear quite easily to the CB as it's on the end of the shaft but the other gears are ordered differently to allow for the TL's bigger flywheel.
Well, made initial enquiries tonight about a flywheel, only ones I can find so far though are from XT125R,s I think they are suitable but not 100% sure so not bought one, will look another day or two for TTR flywheel, would agree with your comment about it being a noticeable mod as I have taken about half of the weight from the flywheel on my Majesty and that picks up much quicker (have done other stuff to that as well though)
It's the same engine as the Yam YBR125, not sure but the flywheel may well be the same. Might be worth checking the part nos. online.
No hay de que Sherpagorri, the mod will definitely help stop the points cam moving around, you may find that a very small amount of oil seeps through but it shouldn't be a problem on a trials bike, it might be worth putting a small amount of sealant on the outer and inner race of the bearing.
Yes it's possible, it depends if you have access to machining equipment and how bad the wear is in the cylinder head at the small end of the camshaft. If this end is badly worn it would need to be machined to take a needle roller bearing to do a good repair.
There are some articles on the Thumpertalk forums, dealing with fitting a bearing behind the advance/retard mechanism to stop the camshaft moving around.
First of all, you'll have to register on the Thumpertalk forums here http://www.thumpertalk.com/forum/ and sign-in so that you will see the pictures
This is an easy way of doing it, no machining required. A good, cheap solution which would be fine on a trials engine. http://www.thumpertalk.com/forum/showthread.php?t=819229&highlight=
If you're not seeing the pictures, do a search for user name craig10, you will see the posts there.
If you still can't see the pictures, PM me your email address and I'll send you the posts as Word documents.
I checked online, the TL 2 piece head has small valves and a dished low compression piston. If you used a head from another model you'd probably need to get a different piston as the compression ratio would be too low because the other heads have a larger combustion chamber. The only other head that would suit your TL piston would be a CB or SL one piece head.
I am about to start a bearing conversion on a 2 piece head with a needle roller at one end and a bearing at the other.
Hi, I have to change the head and camshaft of my old tl125s, but I can´t found those spares. I´m thinking in other honda models parts to fit my honda. Any suggestion?. Thanks in advance.
Any of the heads with cams from the overhead cam models will fit ie CB, XL, SL, CT.
The cam timing is a bit different on the TL for better bottom end power but I'm not sure how much difference it would make.
The one pc head cams have different journal sizes to the 2 pc head cams so are not interchangeable, but a 2pc head cam will fit in any 2pc head, and a 1pc head cam will fit in any one pc head.
The early CB one piece heads have smaller valves than the later 2 piece head, not sure about the TL. The early one pc XL heads have the same size valves as the later XL and CB 2 pc heads.
Ok, time to give credit where it's due after some criticisms I have made on here re SACU licences. Just read on the SACU website that they're going back to £10 day licences for club and some nationals. Hopefully should attract occasional riders back into the fold, might even get out there myself...
From the SACU News Bulletin 4/2011
ONE EVENT LICENCES
The Directors of the SACU decided at their last Management Meeting, held in October that the One Event Licences would come back into use for NATIONAL & CLOSED TO CLUB EVENTS ONLY but NOT for SCOTTISH CHAMPIONSHIP EVENTS.
There will be a new one event licence application form (separate from the annual application form). One event
licences will be £10.00 and a rider can apply as many times as he/she wishes throughout the year. The difference this time with the one event licences is that it will not be carried forward towards an annual licence. Both licences will be completely separate.
These one event licence forms should be with the clubs in the next couple of weeks.
'Also any concern of damage to the lower portion of the fuel tank with having the skid plate mounted to it? Could be quite a bit of stress on the lower part of fuel tank with the skid plate being bashed and bending around a bit'
All the ones going round the Scottish this year seemed ok, plenty of bashplate bashing going on there.
I'm with Ross on the anode theory, but not necessarily just to the steel. The first weld was probably done with the right rod, the second one with a material that will act as an anode to the surrounding metal, just like zinc does on galvanised metal
Happened when I changed the pegs on my Scorpa 125, I put a couple of weld spots on the bottom inside face of the peg so it sits slightly angled up, works fine and you don't notice it when riding.
remember the SSDT is a fantastic proving ground for a new machine, it will either come out with plaudits or blow its' brains out trying!
Big John
No comments on the Greeves but I feel the sales failure of the Sherco 4t was directly linked to their disastrous first outing at the SSDT a few years ago, takes years to build up a reputation for reliability ...and just a few days to destroy it.
the real problem for us at the end of the event and commented upon by our forgiving landowners was the huge amount of litter left behind. So please, let this be a reminder to all and sundry, no matter what the trial, leave the land as you found it please.
Totally agree with Mike's comment re litter.
As well as Chris having a pop at the riders, observing a spectator section at the Scottish is a well known PITA due to the litter left behind by spectators. Lagnaha on a hot day? Couldn't be in a better place, unless of course you have to go round picking up the beer cans, bottles, sandwich packets, sweetie wrappers etc left behind!
Just remember that we're on the land as guests...TAKE IT HOME!!
Tl 125 alternative cylinder EBAY
in Honda
Posted · Edited by craig10
The kit's listed as being for all the 125s but the combustion chamber volumes are quite a bit different between the models. I'd be surprised if the kit just bolted straight on without some other sort of work as TLrider has pointed out. If you're using the standard TL head on a big bore kit you'll be raising the compression ratio quite a bit unless the piston is dished.
A Honda xl185 barrel will go onto your cases after boring them out (sleeve diameter 69mm), with an ATC 185 (dished) piston it helps to keep the CR down, see the picture below.
It's difficult to lower the CR on the ohc engines as you're restricted by the cam chain length.
This is what TLrider means by cutting into the oil gallery, this is one I did last year. I've since had it welded up but the project has kind of stalled.
1.5mm sleeve thickness is fine, especially for a trials engine. Pete Arnold at PACRE http://www.pacre.co.uk/ won't go lower than 2mm but he's building high spec road race engines that have won championships out of the CB motors.
To be honest, it's easier to just fit an xl185 engine or even better the post '79 xl125 6 speed bottom end with the 185 crank and top end (no casing boring required), but where's the fun in that!?!?