Changed the title to this post to represent the subject a little better. Plan to use it as a documentation of the what's being done to put this one back on the road. As could be expected when I pulled the steering head apart the races were dented in the straight ahead position. After reading through this, I believe the PO freaked out when the stem nut stood proud of the yoke and severely overtightened it. http://www.triples.co.uk/articles/articles/yokes.htm I have a set of tapered roller bearings to go in. I can't find the caged ball bearings and don't want to mess with the 40 individual balls. I put a set of the tapered rollers in my BSA Thunderbolt and they have worked out well. Also, pulled the forks apart. One stanchion has a fair amount of damage, like someone used a pipe wrench on it. So a new pair ordered. Had a heck of time getting the plug nuts off the end of the stanchions. Ended up using heat which destroyed the inner rubber seal. Then I read the shop manual which said they needed to be installed with red loctite. Well, that explains it. Guess they will have to be replaced too. Also, no dowty washers in the bottom of the legs just some silicon sealer. From what I've seen so far I'm going to have to go end to end on this bike repairing previous "fixes". I see a ton of sealer around the rocker boxes and push rod tubes. Me thinks the head is going to have to come off.
just catching up here My experience with needles and needle jets caused me to put a set of mikunis on the bike. Supply may be better now but I went through 12 needles(new ones) with a caliper trying to find three that had more or less the same taper. The needle jets also had some swarf left in the cross drilling. Even with all that the bike never ran that well. So I found a set of mikunis off a yamaha triple and used them. Gord
Had a heck of time getting the plug nuts off the end of the stanchions. Ended up using heat which destroyed the inner rubber seal. Then I read the shop manual which said they needed to be installed with red loctite. Well, that explains it.
Which "manual(s)" are you reading? From "plug nuts" and checking the parts manual, your T150 should have pretty much the same arrangement as my T160's - an alloy plug with hex. socket in the bottom of a counterbore, that screws into the top of the stanchion, which also preloads the spring. I've never used "red loctitite" on these, and can't see any reason to. By all means use a smear of blue Hylomar on the threads, if you're someone that believes any thread without something on it on a British bike must inevitably leak oil, but that's about it.
Maybe I wasn't clear. I meant the plug or nut that screws into the bottom of the stanchion that the damper rod goes through. It has a rubber sleeve in it. The factory shop manual says to use red loctite on it. I'm going with blue.
Got my parts in and everything is going back together. New roller bearings feel much better. I'm trying to remember do the stanchion tops and alloy plugs sit flush with the top of the yoke or slightly below or above? Always thought the two cap arrangement was a little odd. I suppose they had some reason but it's not obvious. Also, does the pinch bolt that has the lug for the brake pipe go with the lug to the front or the rear?
I'm trying to remember do the stanchion tops and alloy plugs sit flush with the top of the yoke or slightly below or above?
On the T160's, I have the tops of the ally plugs flush with the top of the yoke. But T160's don't clamp the speedo. 'n' tacho to the ally plugs ...
Originally Posted By htown
the two cap arrangement I suppose they had some reason but it's not obvious.
It is when you're fighting a single cap into a stanchion against the spring pressure while trying not to drop a speedo. or a tacho. on the garage floor ...
Originally Posted By htown
pinch bolt that has the lug for the brake pipe go with the lug to the front or the rear?
Lug to the rear ... pipe runs down behind the stanchion and slider to the caliper (on the rear of the slider ).
Btw, if you have the machined lug/pinch bolt (there are some cheap-looking pinch bolts which are a lug welded to the head of a hex. bolt ), risking stating the obvious, tighten the pinch bolt first, so you can hold the lug with a wrench, before you fit the hose and pipe ... doing it the other way 'round is a tad more difficult ...
Thanks, Stuart. I was browsing some manuals today and see there is a supplement for the 73/74 models that has all the disc brake and associated forks covered. My manual lacks this info. I see where the lug needs to be tilted about 20 degrees from horizontal pointing outward so that the hose doesn't foul the wheel. I'd have never thought of that. Mitch
I see where the lug needs to be tilted about 20 degrees from horizontal pointing outward so that the hose doesn't foul the wheel.
Never knew that either. But I've never noticed it as an issue, there's very little of the flex. hose exposed to the wheel, worst case, I'd just expect the rubber to touch the fender. But where I've fitted a flexible hose (rubber or braided), I look at its natural curve and arrange the hose so this curve is towards the rear, the hose is always slightly compressed anyway so, when it's compressed more by suspension compression, it just curves rearwards more.
Chilly and raining here. This is usually our best time of year to ride. So an afternoon in the shop. Decided while the front end is apart to go ahead and rebuild the brake system. Started on the caliper. After 3 hours its finally apart. As usual using my air compressor the puck on the feed side popped right out leaving its port exposed and the other side not moving. Finally came up with the idea of jamming a golf tee in the port and holding it with a screw driver. Seeing those things come out I'm not putting my finger in there. It sealed it well enough that the other side started moving. After a fair bit of struggle it eventually popped also. Glad I decided to do it as both sides were full of rust. Pucks cleaned up okay. New seals and should be good to go.
Time for an update. With all the rain lately I have been able to get some more done. Wish I was riding more though. Front end is mostly finished, new fork tubes and seals, headstock bearings, tire and tube and brake hoses, caliper rebuilt. Need to rebuild master cylinder. Rear end is mostly apart. Have on hand new shocks, new chain and new tire and tube. Oil tank is out and being flushed, then reinstalled with new rubbers. Rear fender was in pretty bad shape, so sent it out for replating. Birds nest of wiring to straighten out. I'm still continuing to find more bodgery at every step. Lots of cheapo fasteners, the engine mounting plate bolts were really loose. Again I can't believe someone tried to ride this. Missing fin on head. Not going to worry about it at this point. And this is the crowning touch. Looks like the pin was put in from the wrong direction then tightened until it snapped. Of course like this the pin isn't in far enough and the arm wiggles on the shaft. A hammer and drift isn't moving it. Will try some heat on it.
Time for an update. Got the kickstarter pin out. Used some heat and got a pair of needle nose vise grips on it and got it to twist a hair. Kept working it and gently tapping and it eventually pulled free. Have a new one on order. New tire, tube and rear shocks installed. Once chain was cleaned up it appeared in pretty good shape so reinstalled. Oil tank reinstalled On the front end, rebuilt the caliper and master cylinder and installed new brake hoses. Got the brake bled. Newly rechromed fender back from the plating shop
Tropical storm Bill is here so more shop time. When I first looked this bike over a number of oil leaks most coming from the top end were apparent so I decided to pull head. Before I did I checked compression, 120 psi across all 3 cylinders. This on a cold engine and my gauge seem to read little low anyway, so not too bad. Here's what I found after pulling the head. Steel head gasket, timing side cylinder leaking into center cylinder. Note build up of carbon on piston top near leak. Strange dings in top of piston. Other cylinders appear okay. cylinder head showing leak, fairly carboned up. Head seems flat when checked with straight edge. (timing side on right) the culprit head gasket. (timing side on right) I'm going to order gaskets from LP Williams, I'm thinking the composite flame ring type. Used one on my Commando rebuild with good results, but did diligent retorquing.
Piston tops and combustion chambers will get a thorough decoke. The bores look in pretty good shape. No scores and even some faint cross hatching. Pistons have 70/9741 stamped on the top so they are standard bore not oversize. I did a "poor boy" leakdown test on the valves by dumping petrol into the combustion chambers. No leaks. The ts combustion camber that had the dinged up piston also had some divots in combustion chamber. Almost like something was banging around in there. Can't image what. They look like they have been there a long time and were full of carbon. Compression test results were around 125 for all 3 cylinders on a cold engine. Given that, I think I will leave the pistons and valves alone, this time. I think I found the source of most of the oil leaks. The rocker box gaskets had major gaps and the 4 outside bolts on the rockerboxes were barely finger tight. I put composite rocker box gaskets on my t140 and they stopped some bad leaks. Leaning toward using them again.
The ts combustion camber that had the dinged up piston also had some divots in combustion chamber. Almost like something was banging around in there. Can't image what. They look like they have been there a long time and were full of carbon.
Possibly a dropped valve in an earlier life?
Originally Posted By htown
I put composite rocker box gaskets on my t140 and they stopped some bad leaks. Leaning toward using them again.
One of the problems with the triple rocker boxes seems to be that they 'shuffle around' as the engine heats and cools, eventually 'pushing out' the gasket somewhere and allowing a leak. I believe Dave Madigan (and others) have successfully dowelled the two 1/4" bolt holes (parallel to the 5/16" head bolts) to stop the 'shuffling'?
Many use the different thicknesses of available copper rocker box gaskets to get the rocker geometry as correct as possible.
The type of composite rocker box gasket I used on my t140 was a thin piece of aluminum with sticky gasket material on both sides. I believe it is call a cov-seal. Supposed to be able to deal with shuffling. I was going to order parts from L P Williams. Hopefully, their composite gasket is this type. Will need to check with them.
Got the rocker boxes off and found this. This valve is the worst, others range from some "dimpling" to none at all. What to do mushroom adjusters replace the worst valves and lap-in. redo the head completely I'm really hesitant to do the last as compression is decent and valves don't leak with combustion chambers filled with petrol. I'd really like to get this bike up and running before doing a complete overhaul.
The real question is how soon do you plan to tear it down to do what you did not do this time.
I get the trepidation, and the desire to simply assemble it, and ride. Realistically it is nothing but time, and money well spent on a complete rebuild. I work as a mechanic, and the customers I don't like to see are the ones that ask for the cheap fix, dozens of times over.
Every time you tighten a bolt, might be it's last time. Threads strip, parts shear... 2 hours after doing heads, a gear shaft seal lets loose or the throttle cable breaks.
I am a firm believer in doing a complete job, buying all new parts (where you can), and doing all the needed machine work. The only thing I dislike more than pushing a bike is opening it up twice. What is really lost in gauging the main bearings, and replacing the seals? Same for having the head completely worked. Save a few bucks each week, and have it done.
From the looks of all the Picts. you've posted... That's one well worn engine with more than it's fair share of "quick" fixes.
What to do mushroom adjusters replace the worst valves and lap-in.
Mushroom adusters on their own won't fix the problem even temporarily.
Replacing some of the valves is only sensible if you plan to stick with standard valves long-term; if you're planning to fit lightweight valves when you "do a complete overhaul", you risk having to discard perfectly-good second-hand valves?
One other option you might want to consider is grinding the ends of the valves flat and fitting 'lash caps' to bring the valves back to the correct length? Fine details: Big D should be able to advise? If not, one of the Triple Tecs definitely can.
Before I spent a dollar on a triple of unknown heritage I would run it and check the oil pressure. The center main bearings are known to for wearing out starving the rods of oil. The next thing is one of the rods exits the crankcase taking the cams and cylinder with it.
"When the engine is started from cold, pressure may be as high as 90 lbs. p.s.i., reducing when hot to the normal running figure of 75/90 lbs. p.s.i. at three thousand rpm."
If the pressure is much below 70 lbs. p.s.i. @ 3,000 rpm I would not operate the engine until the reason is found. There are other reason beside the rod and main bearing clearance, but these are of the most concern!!! John
Thanks for all the replies, guys. Special thanks to Stuart for sticking with me through this rehab. Have spent a few days studying the parts and having a think. Come to the conclusion the PO put this back together using the 69 bottom end with the 74 cylinders and head. The rocker box casting have 7/73 dates on them, the valves measure 3.74 so they are the "short" type used from mid 73 on and the adjusters are the "captive ball" or long type that were used with the short valves. I looked into using the "lash caps" but the ones I can find run around 60-80$ a set. I would also have to have the valves machined to use them. However, I have gathered from various posts I would not have to have these "short" valves machined if I use the early "short" adjusters for the pre mid 73 bikes. Only problem is bike came with a set of new long, post 73 mushroom adjusters, so I would be out their cost. Looks like best alternative is a set of new valves. I found a set of nos Alpha valves for not a whole lot more than the lash caps. This will allow me to also use my new mushroom cap adjusters. I guess potential wear would be a down-side but I doubt if I will put over 1000 miles a year on the bike as I have others to ride. Plan would be to then lap them in and get the head back on and try to get this thing running. This will give me a chance to get an oil pressure gauge on and see what shape the bottom end is in per John's suggestion. Can also do a hot compression check, listens for noises, smoke ect. If it does need a rebuild I can go ahead and use the new valves anyway. I'm 99.9% sure I would never use a light weight valve. The only downside I can see to doing it this way is I might have to strip the top end again real soon, so a few hours labor and the cost of some gaskets and I'll hopefully have a better picture of the engines health. By the way the guides have rubber seals on them. I found Kibblewhite manufactures them, so I was planning on getting a set of those also.
I am gld to hear you are finding a route to follow.
It also pleases me that all I bought with my bike was the lower 1/2 of an engine. There are so many combos of miss-matched parts on these old bikes that it leaves me shaking my head in amazement. I guess it all comes down to your own research, and what you find will or will not work together.
Thank goodness for these few forums, and those that share their time, and experience.
Plan is to go with the copper head gasket and rocker box gaskets in case it needs to come apart again in the near future. I understand they are reusable if you anneal them. I understand I need to use some sort of sealer around the drain dowels. Should the gaskets be completely coated with something on both sides? I already have a tube of Hondabond, equivalent to 3 bond. Should I use it or something else?