If you've got the Honda part number, any Honda dealer can get you it if it's still available, normally the price is the same across the dealers for genuine parts.
You might need to register on the Thumpertalk forums to see the pictures
I've line bored a head and fitted a needle roller / ball bearing set up on the cam but not had it running as yet, the engine's in my garage waiting to go in.
Is it OK to fit the 2 piece head type 124cc top end on earlier 122cc engine? - Yes but you'll need a 98 link cam chain (100 on the 122 engine) and at least the rear tensioner blade off the 124 engine, possibly the front one as well.
This engine had a problem many years ago, could the fail be down to mis matched parts? - Unlikely, the main cause of death is dirty oil or folks taking off the clutch cover to clean the centrifugal filter or whatever then putting some sort of gasket sealer on when replacing the cover. A piece of that then comes off and chokes the 1mm diameter hole that feeds oil up the right rear head stud to the camshaft, then it's curtains. You really need to make sure the oil galleries are spotless where the oil feeds round to that stud, and don't use gasket goo on the casings, the only place it's needed is a very thin film between the 2 halves of the head.
If you can mix the barrels will it be OK to use the CB100 head on the 124cc barrel? - If the pitch of the head studs is the same then maybe but there's a lot of variables. You'll need to check that the combustion chamber is the same volume on the 124 head and the CB100 head, if the CB is smaller then you might end up with too high a compression ratio or the valves running too close to the piston. Also depends on what piston is fitted, the proper TL 124 engine has a dished crown to lower the CR but the CB and XL 124s have a raised crown. As mentioned above, the TL cam has different timings but any of the 2 pc head cams will fit.
The problem is that as TLTEL says, lots of parts were swapped around on these engines back in the day so it's anyone's guess what's in there.
From memory the CB100 engine has a smaller gudgeon pin than the 125 so unless you changed the crank there's not much can be done there.
Also, it may be regarded as heresy but don't rule out fitting a Chinese replica engine, my mate has fitted one into an old BSA frame and it's been totally reliable, they can be picked up for £150 all in with all the electrics included.
Probably the nearest to you would be the Stevenson or Dalmellington clubs in Ayrshire http://www.stevenstonmcc.co.uk/Links1.htm or Cumberland County mcc in the North Lakes area around Caldbeck
You'd be best working back from your wanted compression ratio with the piston you have before getting a spacer made, otherwise you might be out of pocket for another piston as well. Remember to check your valve to piston clearances using putty or similar when boxing it all up.
Not really familiar with that specific engine Ross but the normal BSA unit single seal is done by taking the clutch off then removing the large alloy plate behind it. That gives you access to the gearbox sprocket, once that's removed you should be able to pry the seal out in situ.
Not really familiar with that specific engine Ross but the normal BSA unit single seal is done by taking the clutch off then removing the large alloy plate behind it. That gives you access to the gearbox sprocket, once that's removed you should be able to pry the seal out in situ.
I don't know these engines, only the tl125 series but if it's points ignition with a battery and not CDI, check with a meter that the points are definitely making and breaking and that you've got voltage at the coil . If you touch the points wire to earth and then break the connection with battery power on the coil you should get a spark at the plug, making sure of course that the plug body is well earthed. That way you should be able to isolate it to the points or coil. Could be that. the isolating washers are incorrectly assembled at the points wire connection.
If you're going to the bother of fitting new stem seals, get genuine Honda ones if they're available. I've found on my Honda single trail bike that the pattern ones give up quite quickly and then you're back to square one.
I am accustomed to the cub gearbox where adding the teeth on each of the MS and LS gear pairings = 45, so was a bit thrown by e.g. comparing 2nd gear on the TLR250 and the TLR200, 17/33 vs 16/33: same number of teeth on the CS pinion but they can't be the same pinion as the pitch circle diameter needs to be different.
Maybe the gear shafts are on a different pitch on the 200 and 250 engines (unlikely), or the cut of the teeth is different. If the teeth and the shaft pitches are the same then as you say the mesh wouldn't be right due to the pcd. Maybe the 26t gear is just catching the mesh, ie with a lot of backlash?
Me too. I've about 70% of an ME07 engine bottom half in not great shape. I'm having a frustrating time trying to figure out what I've got and without a parts manual I'm not even sure all the gears are actually for an ME07 engine and what the commonality (if any) is with the TLR200 (MD09) engine and the other Honda singles in the same family (XR200 etc).
Oh, and it definitely needs a new countershaft as I deduce a previous owner welded the sprocket on at some stage and then ground through the shaft to split the cases - its not pretty.
I've counted all the teeth on the gears and made a table for reference; when I feel it is definitive I will post it for info. What confuses me with the 2nd gear pinions is that I count MS = 17T and CS = 33T, but on the TLR200 CS is also 33T with 16T on the MS - is that right, so the CS pinsion for the 200 and 250 have different size teeth and pitch circle diameter - or the MS pinion I have is actually TLR200? The RTL 250S 1989 manual (one of the links in this thread) show a 17/33 combination for 2nd gear.
Does anybody have a parts manual for an ME07 engine and would scan the transmission page for me? Anybody want to sell me a parts manual?
Nicely done Craig. A much bigger job doing it all on a lathe.
For the one piece head I've thought about putting in a large ring that will encompass the lobe cut outs and the original journal size. THe hole will be larger than the original journal. I would then make a bronze split ring that matches the cam journal with an appropriate od and flange to mate up to the new ring in the head. Haven't gone much past this thought, no sketches or measurments at this point just a thought.
I'll have to register on Thumper Talk and check out the photos.
I see the small end being a bigger problem on the one piece head due to the depth/diameter ratio more than the big end, an allusion on my part?
This was the jist of the thumpertalk thread, a shimmed bearing in the housing, drturnip's been running it for a year with just minor oil weepage
The scrap heads I got were both worn out at the small end, the large end was actually acceptable on them.
I've bored the small end to 28mm on the 2pc head I'm working on, it's a bit nerve wracking doing it on the lathe due to the overhang of the tool from the toolpost. I'll get a video up of it soon. Might not be too difficult on the 1pc head if you bore the chain side wall first to take your large support ring. It's an easier job to fit a bearing on the larger journal on a 2pc head as it's 34mm od with 32mm lobes so it can be bushed to 35 to take a bearing, if I remember right the 1pc head cam has a 30mm journal with 32mm lobes so not so easy without making a split bush as you say.
Re the lad asking about the cams, the timings are different, not sure how you could tell the difference without putting them in a rig and timing them with a degree wheel. TL cams are like rocking horse doo-doo, I expect a lot of what's being offered are standard CB or XL cams.
It's a 2-piece head, originally I was going to use normal ball bearings 2 off 61807 47mm od at the cam chain end, but I ballsed it up and had to take it out to 48mm so I'm going to use a needle roller instead, but it needs a bit more work to keep the inner race in position on the camshaft. Doing it all on a lathe so not so easy to get the accuracy. Pete Arnold at PACRE just runs the cam direct in a needle roller at the small end on his race engines, 28od x 22id. The original idea came to me from a guy called Nigel Houlston who turned down the small end of the camshaft and made a hardened 'tyre' to run it in a needle roller of 28mm OD with the 61807 bearings at the cam chain end.
I'm probably going to do a 47mm one as well, as originally planned, I bought some 'scrap ' heads off ebay to experiment with.
Think it'd be a struggle with a one piece head without welding in an alloy ring to take the bearing at there's not much material thickness at that diameter.
I actually did an outrigger bearing set up on a one-piece head which was total overkill.
If it's a standard TL head with the domed piston on your big bore engine, the CR must be pretty high! The standard TL piston is dished, or at least the one I've got in the garage is.
I've actually got an xl125k2 but the engine architecture is basically the same. I've got various projects on the go at the moment using xl185 and ATC185 parts. I've also just line-bored a head to take roller bearings on the camshaft just to see if it was do-able, I'll upload some pics once it's finished and tested.
Like you, I'm also in engineering so these things just have to be tried!
Tl125 Advice Needed.
in Honda
Posted
The one and 2 piece heads have different journal sizes and are not interchangeable but as far as I'm aware any cam will fit in it's own type of head.
I've measured them as follows
One piece head cam brand new: Journals 29.93 / 19.93 Lobe nearest sprocket 31.95 Lobe furthest from sprocket 31.50
2 piece head cam (used) : Journals 33.96 / 21.96 Lobes (showing slight wear) 31.7 / 31.3
Clearance of journal to bore in 2pc head 0.1mm measured with plastigage, engine was running fine
Check out Vincent Crabtree's stuff in pdf format, there's a whole page on cams http://www.google.co....53899372,d.d2k
Craig