tlrider

Delrin melts at 347 F, my material was speced at around 325 if I remember correctly. I know I cooked it at 315 for about 3 hrs and noticed no significant changes in dimensions or appearance. Try it and see how it holds up.

I had a Powroll bore and stroke done to a stock TL cylinder in the early 80's to 161cc or there about; it made a significant difference. I have no experience with the drop in 145cc kit and I'm sure it works fine and it's probably the less expensive route. I bought my current TL with the 200cc cylinder kit installed and like it a lot, being a machinist I decided to build another. It is quite a bit of work as there are fixtures to be made and you also have to recut the valve pocket in the piston. When boring the cases you break into the oil passage on the back of the spigot hole which feeds one of the transmission shaft internals.It is recommended that this be welded and recut but my bought one was not done that way and I rode it for 10 years before tearing the engine down due to a broken kick start gear. sherpagorri, to answer your most recent question there is not a kit available to my knowledge. The stock TL head will bolt right on with no mods necessary though there are several you can do. I bought mine off ebay, piston and cylinder together so I beleive they came off the same bike. The seller had good photos and the parts looked in decent shape, there is a little pitting on the cylinder walls. It honed nicely and the bore is well within tolerance so I'm going to leave it as is. If you're really interested in doing this I can write you a detailed list of what you need to do.

You're not crazy; I've seen them too. I've been looking and can't find the website again, probably a link off a link discovery. I'll post the link if I find it. Scooter

I made my own, CNC machined from phenolic, TL125K profile, TL125S shield thickness also added an o-ring on the head side to eliminate the gasket and it has straight hole to help increase the air velocity sightly. I've had one on my bike for about 8 years now. I can see how many I have left if you're interested. Scooter

If you are going to remachine the cases I recommend getting the big fin ATC 200X cylinder and piston, 65mm bore I think. You will also have to shorten the cylinder to match the 125 stroke but you end up with a 166cc engine. I have one in my TL and am building a second one for a Fraser frame I have. Quite a few people have ridden mine and commented 'This is what Honda should have built'. Scooter

Greetings Everyone, I have just recently acquired a TLR250 and need to replace the rear wheel bearings. There is no online parts fiche available for this bike that I'm aware of and the parts fiche I've found that most resembles my rear wheel is an 85 XR350 though one of the bearing numbers does not match. There appears to be a threaded retainer on the sprocket side of the hub that has four indentations to lock the ring in place, does anyone have a procedure for removing this retainer? I'm also looking for the bearing numbers and dust seal number so I can order the parts before dissassembly. The brake side bearing is visible and is a 6202LU bearing. I can not see the bearing number on the sprocket side due to the retainer. All help and suggestions are greatly appreciated. This bike is an incredible improvement over my TL125 with modified rake and 166cc big bore, but I still love my TL!

TLTEL is correct. SL100 will fit but XL are wider, less offset on the XL. SL100 thru SL100K3 has product code 110. P/N is 53230-110-305. They show up on EvilBay from time to time. Scooter

I agree with mcman56 and B40RT. Enlarge your pilot jet. I drilled mine but don't recall by what amount. Keep in mind you are dealing with area of a circle when enlarging the hole; for example an .020" hole enlarged by 25% or .005" changes your area from .0003 square inches to .0004 square inches or 34% if my math is correct. I.E. a small change in diameter is a larger change in fuel flow. The heat shield, which is probably broken off your carb insulator, is crucial in hot weather. The TL's had them stock but most were broken trying to remove the carb insulator from the head. I was riding the Ahrma Trial at Mid-Ohio a few years ago when it was very hot. I rode up to another TL rider who was having problems similar to yours but worse. He saw the heat shield on mine and asked what it was and I explained it's function was to prevent the gas from boiling in the float bowl. I saw him later with an aluminum foil heat shield and he was running again with no other changes. Over the summer I saw a TL rider who had done the most ingenious thing. He had a battey powered fan which ran off 4 C or D batteris and had a flexible arm; the battery pack was just the right size to drop into the front lower motor mount and the flex arm allowed aiming the fan at the cylinder. Brilliant! Said he got it at an outdooor store.

Hey guys, Regarding the 122cc and 124cc top end swap here is what I have found. I have a 166cc engine where a 200cc (192cc) cylinder is shortened and put on a TL125 'K' bottom end (122cc). I'm building another and want to put the two piece head from the 76 'S' model on it (124cc). It's going in a Fraser frame so I want the two piece head. My modified 192cc cylinder and the 124cc cylinder are the same length at 2.677" (68mm). I don't have a 122cc cylinder, can someone measure for me? The 124cc cylinder OD is 2.455" (62.35mm) 'S' case ID for cylinder is 2.5" (63.5mm) unmodified 'K' case ID is 2.515" (63.88mm) Bunyan, I can't explain why yours didn't fit, manufacturing variances? Combustion chambers visually are the same size between K and S heads. Cam chain and tensioner: craig10 is correct in the 124 two piece head has a 98 link cam chain and a shorter tensioner blade due to the cam shaft lower in the head. However, the adjuster in the bottom end is higher than on the K engine. Using the the 124cc S head with a 122cc length cylinder (needs verification as stated above)and the 98 link S chain, the S tensioner is too short. With the adjuster all the way out I can not get enough tension on the chain. I replaced the original longer K tensioner and with the adjuster all the way in, bottomed out the tension is just about right without gaskets. I would prefer it to be a bit looser at full adjustment. Once the engine is together with base and head gaskets, if the chain is still too tight I plan to remove the adjuster screw and remove some material between the threads for the case and the shoulder for the o-ring. This will allow the adjuster screw to go deeper in the case elongating the tensioner. I found the 100 link chain to be one link too long for this combination. I hope this is not too confusing. Revision: Upon further inspection the lower adjuster pivot points are in the same place. The S tensioner is shorter than the K but they do not have the same radius leaving the 98 link chain too slack. The slack is taken up on the S engine with the changes to the guide blade opposite. It pushes the chain closer to the centerline of the cylinder taking up the slack.

Hello everyone, I have a Fraser Mk2 frame for the TL125. I want to replace the rubber swing arm bushings but they are not the same size as my TL125 K1 bike. The bushings I need are the following dimensions: 12 mm ID x 27 mm OD x 41 mm long, the TL bushings are 12 x 25 x 35. Does anyone know what bike these bushings are from? Thanks, Scooter

Sirius out of Canada has TL125 carb rebuild kits on ebay pretty regularly. The kits usually have a new drain screw in them. They probably have TLR200 kits as well. Another option would be a motorcycle breaker if there are any in your area.

Check the condensor wire at the coil. Mine broke there once and I had no spark.

Craig, where is Bolton?

Ooops! I didn't realize I was not directly addressing the original poster of the thread, sorry guys. 170cc Big Bore....here's what I know. My engine was built by Hoyt McKagen, may he rest in peace. I met another builder but have lost contact with him. Being a machinist I'm planning on doing another one to put in the Fraser MkII frame I have. An ATC200 large fin cylinder is used as well as a dished piston from said ATC for low compression. Depending on which overbore you have displacement should be 168-170cc. The jug and barrel are shortened to match the TL125 stroke. Same height as stock cylinder I presume. The cases are bored to fit the larger jug. The oil passage in the case that feeds the head must be welded and re-machined as it was cut in to during boring of the cases. I only know this from having been told so by the engine builder. Put it back together...and yes it is a good set up for running. A few people have said 'This is what Honda should have built.' It does make for a very nice ride, you lose the off idle cough and the bike has enough grunt to loft the front end when you need to. If anything I'm timid on the throttle, the bike will pull itself out of trouble. BPS offers 'Our 180 big bore kit complete with piston and gaskets (exchange only).' at 396 Euros. I was to get cylinder, piston and all machine work for $500 US about 3 years ago. This article on Thumperpage has a lot of info on Honda piston and cylinder combo's for the TL. http://www.thumperpage.com/articles/tl125faq.html I've also been told that installing an XL125 exhaust valve and reducing the intake diameter with an epoxy or Devcon aluminum to increase velocity aids in reducing off idle cough. Here is another option that seems to have worked. I was running 93 octane pump gas with octane booster and lead additive. The motor ran great at low rpm's with no cough but I would get detonation at higher speeds on the loop. Recently I tried CAM2 race gas which is something like 108-110 octane with lead. I picked up top end performance but seemed to lose some low end response with just a little cough. A few years ago I made some pattern carb insulators with o-rings on the head side. They allowed me to lock down the carb nuts without distorting the carb and get a good seal. With the lose of low end I decided to make some new carb insulators with a straight hole rather than with the taper as the originals have. This seems to have corrected my problem, the straight hole seems to add just enough velocity to eliminate the cough using the race gas.

Hey bunyan, I have a TL125 with a 168-170cc big bore and have both chopped the lower frame rails and the steering angle. I bought the frame modified and the modifier had cut about a 5/8" to 3/4" wedge from behind and below the steering stem. He pulled the lower portion towards the rear of the frame thus steeping the rake. I thought the bike steered like a Yamaha TY175. It was very responsive and the bike did not fall into the turn as does the stock geometry. My dislike to the mod was doing any kind of drop off or dropping into a gully where the front wheel had to go back up the other side immediately without a flat spot at the bottom. The sensation was that the forks were going to fold under the bike. I did measure the angle compared to a stock TL and have it written down somewhere. I'll have to find it. The wheelbase shortened by about 3". I rode it like this for a year or so. I decided to de-rake the bike. I cut the weld and moved the lower portion of the steering stem forward about half the distance of the original mod. I made a steel U shaped bracket that slid on from the bottom and welded it all the way around. I like this much better. The bike still turns tight and does not fall into the turn. Drop offs are much more comfortable but the stock forks are still lacking. I haven't figured out what to replace them with. Mariocchis off a Fantic have been suggested. I can't comment on what rake is legal, is there even a legal spec? I'm in the States. What I can tell you is the bike seems to handle fine wide open in 5th gear across an open field. I run a 12 or 13 tooth front sprocket and a 60 tooth rear. Am hitting 40 MPH or so? I also cut out the lower frame rails and added a 1/4" AL bash plate. I modeled it off what BPS Engineering of France shows on their TL Pro kit. It's a nice mod adding more clearance in the front and it slides off rocks and logs better. Another important mod I got from BPS is adding supports from the sub frame, the portion going from the footpegs up to the rear shock mounts, to the main vertical backbone near the rear engine mounts. These are also visible in the BPS photo but you have to look closely. These stiffen the ride imensley and I just recalled I made a triple tree brace. Modeled it off the image from the parts list that shows it as an option for the bike. Mounts between top triple tree pinch bolt on one side and lower triple tree pinch bolt on the other fork. This gets rid of the 'wiggle' in the bars when doing drop offs. Sorry to be so long winded, hope you find this useful. Scott

Hi guys, I have been following this thread with great interest. I acquired a Fraser Mark 2 frame for the TL125 and was wondering if anyone has any history on this model. I have found very little info on the net. The photo is like my frame and I intend to build it to look similar to this. I'm doing a 170cc big bore and different fenders. I appreciate your comments. Scott Fraser Mark 2 TL125

John, Good to hear you have your problem sorted out, glad to be of help.

John, These are still available in the States thru Honda. Part number is 16955-028-004 Packing, cock. The middle number 028 indicates the part first appeared on the S90 in the mid '60's, here in the states anyway. Point being that part is used on many Honda's so you should not have a problem finding it. If you have trouble let me know, I'm happy to send you some. Scott

What engine oil are you guys using in these old Honda four stroke trials bikes? Natural? Synthetic? Blend? 10w-40? 20w-50? I have a TL125 with a 170cc kit. Thanks, Scooter

Oldguy, The adjustment screw attaches directly to the tensioner via a sliding yoke if you will called a hinge item #20 in the parts list. THe top of the tensioner is anchored by the bolt (#22) on the head to the rear of the points cover, there is no spring. Adjusting the screw moves the hinge up or down causing the tensioner to bow. See the parts diagram here: http://www.mrcycles.com/fiche_section_deta...4&fveh=3705 This is an online parts fiche, the link should take you to the page with the cam chain and tensioner. If not find the Honda Parts menu on the left of the home page, click Honda Motorccle Parts, pick year and model then desired parts diagram. The exploded views are great for understanding what's going on.

Hello Oldguy, To adjust your camchain: I do it with the engine running at operating temp so I can hear it. 1) loosen the locknut on the adjusting screw located behind the cylinder on the left side. 2) adjust the screw counterclockwise listening for a change in sound 3) tighten and loosen several times as necessary for your confidence level 4) tighten the locknut 5) do not overtighten the chain as the cam journals are machined right into the aluminum head. Overtightening will cause premature wear to the cam journals. An alternative is to remove the altenator cover on the left side of the engine, this is not in an oil bath so if you lean the bike to the right you won't lose any oil. You will be able to see the cam chain behind the rotor and should be able to see it tighten and/or slacken as you adjust the screw. This method is with the engine off mind you. I'm glad to hear you are doing this. I bought a parts bike from a guy who never adjusted the camchain on his TL. THe camchain ate through the camchain tunnel on the inside of the cylinder. Looking from the front of the bike there is a narrow space between the cylinder wall and the camchain tunnel on the right. He let the bike sit dissasembled for about 10 years so it became a parts bike. Good luck...

What's the 2k hardener trick? THink this will help TL125 front brakes?

Terry, Yes I'm the guy with the 'S' carb. I stopped in Friday evening and it is nice to be able to stop and check on things. I'm glad to know they contacted you. You must have already made an inquiry. Nice folks, very helpful. The carb he has is a Sheng Way made in Taiwan. The quality looks very good. We put my OEM jets in it so the threads are the same, looks to be an identical copy. As I said earlier they may have bought Keihin's obsolete tooling. I know that is not an uncommon practice. I'm confident it will work for you. The carb I took in has not been on my bike, it is a spare. I bought it off ebay listed as an 'S' carb. The one on my bike, also an ebay 'S' carb is almost identical. THe one on my bike has the number PC 04A. THe one I compared to Re-Mx's has the number PC 04B. The A carb has a few additonal gussets and what appears to be a vent or overflow hose just in front of the fuel inlet about 1/2 way up the barrel. The B carb has just a tiny hole where the vent/overflow hose is on the A. THe B has the important gussets along the barrel. Both carbs have a 38 pilot jet, mine had a 105 vs. an 89 main jet. I'm not sure what size main is on the bike. I'll check and let you know but I can't get to it for a week or two. Remember I have a 168cc big bore and at one time I drilled my pilot jet larger which helped with idle and the off idle cough, it doesn't. The bottom of the globe? I guess you don't have overheating problems in Antartica....where are you? YOur welcome, I'm glad to have helped. Scooter

RMXBOY, I have not run my bike without the heatshield. A couple of years ago I rode the Trial at AMA Vintage days at Mid-Oho. It was a hot July day, short loop, looooonngggg lines at the sections. Another TL rider was having problems keeping his bike running. I saw him alittle while later running smoothly. He had jury rigged an aluminum foil heat shield between the cylinder and carb so I guess it works. Dimensions: same width as the flange @2.4" , length to bottom of float bowl @ approximately 3.2". THe flange is an extension in the same plane as the head side of the insulator, it is one piece. The 'K' model flanges were .0625"(1.5mm) thick. Most of them are broken since the easiest way to break the bond between the gasket and head was to use the flange as a lever, so they broke. I made mine to the 'S' thickness of 1/8" (3mm). I'm taking these measurements from a carb in hand. The bike is elsewhere so I can't give you the total block thickness. I presume yours is a broken original. I forgot to bring the camera home from work so I can post a photo, still digitally challenged here. Scooter

RMXBOY, According to the TL parts list both the 'K' and 'S' carbs have the TL's product code of xxxxx-355-xxx. To the best of my knowledge the product code denotes the model the part first appeared on. The part can and may have been used on subsequent models as many of the TL parts are carry overs from the CL (?) and SL 125. If the 'S' carb was used on anything else I don't know and really have no idea how to find out with out looking at part numbers for other bikes. I do know the 'K' and 'S' are jetted differently. The 73-75 XR75 carbs are 20mm but the flange holes are at an angle as opposed to horizontal. I think they first appeared on the XR so they would have a different product code. The carb Re-Mx has for the 76 and later XR75 appears to be the same body as the 'S' and we believe only the jetting to be different. I'm going to take my spare 'S' carb there and do a side by side comparison. Sorry to say I have no idea on the 22mm XR100 carb. Terry, Sheng Wey is a Chinese carb maker that I believe makes a repro S carb but I can't find one on the net anywhere. I've seen them on ebay in the past though that's of no help now. B&J Racing offers a bolt on replacement I have been told is off a late model XR100. If you want an authentic appearance go with the one from Re-Mx and get a jetting kit which are available on ebay from Sirius Consolidated I believe, they're listed frequently. Any specifics you are looking for on the Re-Mx carbs? They have OEM and repros. I drive by them on my way home from work so stopping by is not a problem. I believe I made the spacer from Garolite XX which is a paper based phenolic. I thought I ordered a flame resistant variety but I can't find what I think I ordered from McMaster-Carr. The material would barely burn with a flame held to it and would go out immediately when the flame was removed. I also oven tested it at 350 F for about 3 hours. Being a phenolic there is minimal heat transfer. It is made to 'S' specs, major difference is the heat shield is 1/8" thick as opposed to the 'Ks" 1/16". I really should post a photo, from standing distance you can not tell it's a repro. I've thought of making another batch with the plan of putting an o-ring on the cylinder head side and eliminating the gasket. I need to check operating temps for o-ring materials first. The other change may be to reduce the taper of the spacer from the carb to the head, this would increase the air velocity somewhat. No worries on the questions. I'm happy to share some of my knowledge in exchange for useful info I've gathered here over the last several years.