Triumph T140 Bonneville rockerbox spindles are susceptible to leakage, specially on large mileage bikes. Merely replacing the little rockerbox O-rings typically is not enough. Numerous O-rings on the sector are sub-conventional in phrases of high-quality. Quite a few are pretty simply just the completely wrong dimension.
However, you could need to consider a selection of O-rings ahead of you discover a pair that operate. But they are low-cost to obtain and quick to switch. Correcting them just seems additional sophisticated than it is. Here’s how to do it.
With the motor off and chilly, loosen and remove the aluminium inspection addresses from the entrance and rear rockerboxes. Every single deal with will be secured by six Allen screws. Loosen them just a portion of a convert to just take off the initial load. Now undo the Allen screws incrementally. That assists stay clear of distortion. When you’ve got turned the Allen screws when of 2 times, you can loosen up and get rid of them immediately.
There should be a paper gasket underneath each and every inspection cover. Clear away this gasket diligently by scraping and peeling gently. Do not use a tough scraper these kinds of as metal. Use a plastic or aluminium scraper of some type. Loosen the valve adjuster nuts on the rockers. This takes the load off the rocker spindles and the valve equipment. Do NOT omit this phase. You want only make certain that the rockers are free. You should not get rid of the valve adjuster nuts.
If, nonetheless, you see that a single of the valves is in the absolutely open up situation, carefully rotate the motor (utilizing the kick starter) to near the valve. This operation also can help consider the load off the rocker equipment and the rocker spindle. To facilitate closing a valve, you could possibly choose to clear away the spark plugs to minimize cylinder force. The motor will turn more than substantially easier this way.
But how will you know if a valve is open up? Uncomplicated. Look at the finishes of all the valves where by they meet the rocker adjusters. If one of the valves is pushed all the way down by the rocker adjuster, it is really open. You might want to transform the engine above a few instances to familiarise your self with the valve movement. It will come to be crystal clear when you glimpse at it for a when.
Up coming, you will have to have a specific resource offered from good classic Triumph sellers. Low cost to purchase (usually a few kilos or bucks), this software is just a tapered tube about one particular inch (25mm) very long developed to suit snugly about the rocker spindle.
To use it, follow these simple ways. Initial loosen and remove the appropriate hand dome headed nuts that protected the rockerbox oil feed pipes. There will be 1 for the entrance rockerbox, and one particular for the rear. The pipes are joined at a T junction which is in turn related to a rubber pipe. Eliminate the copper washer from beneath each and every dome nut. Take out the oil feed pipe. Remove the copper washers powering the rocker oil feed pipe. There should be a single on every rocker spindle.
Now temporarily change the dome headed nuts, but not the copper washers. Preserve the washers for later reassembly. The plan at the rear of this phase is to get the rockerbox oil feeds out of the way. The dome headed nuts do not require to be fitted tightly. They are changed only to safeguard the threads on the close of the rocker box spindles. Wind them on just a few of turns.
Next, working with a hide mallet or rubber mallet, carefully tap one of the dome headed nuts. This will travel the rocker spindle across the rocker box from the right side of the engine to the remaining aspect. You should not faucet the spindle a lot more than a handful of millimetres. The concept is to slide it across just ample to expose the O-ring and O-ring groove on the other conclude of the spindle. Keep tapping carefully until eventually you can see the O-ring. Do this on the entrance and rear rocker boxes. You may well have to loosen the dome headed nuts a transform or two to facilitate this. It will be apparent when you are doing work on it.
Next, acquire a little resource with a level or hook. Carefully lever off the outdated O-ring from every single spindle. They will now be flattened somewhat than rounded. You can just pull these off and toss them away. Wipe the finish of the rocker spindle with a rag and check out that almost nothing is weakened. If the spindle is ruined, it will have to be changed. If the spindle is in seemingly fantastic situation, oil it with some refreshing motor oil. Then oil a single of the O-rings. Gently roll the O-ring more than the end of the spindle and make certain that it is a comfortable in good shape in its groove. Do this with each rocker spindles.
Now you need that unique device pointed out earlier. Oil it on the inside with fresh motor oil and slide it in excess of the O-ring and rocker spindle. Get care not to snag the O-ring. Following, remove the dome headed nut on the end of the spindle and quickly change the rocker oil feed. Replace the dome headed nut and gently tighten even though keeping the special instrument on the other stop of the spindle. The plan is to gradually attract the spindle and the O-ring via the little tapered tube. This allows end the O-ring from snagging as it truly is pulled back into the rocker box.
Do this with both equally O-rings. Check as very best you can that both of those O-rings are seated. If you lower or harm one, swap and consider once more. Bear in mind to use a good deal of oil. The oil feed pipe is made use of right here purely as a spacer. You’ll see why quickly plenty of. Some house owners test to tap the spindle again by from the remaining aspect. You must keep away from this. Just use the technique over. It is really slower, and extra controlled.
Next, anneal the copper washers. There need to be four one particular to fit at the rear of and one to in good shape in entrance of the rocker feed pipe on the appropriate hand aspect of the motor. To anneal, keep just about every washer in a naked flame until finally it’s cherry red, then drop straight away into chilly h2o. Copper can be safely and securely annealed this way. Ferrous metals want to be cooled slowly.
Get rid of the rocker oil feed pipe and suit a copper washer on to every single spindle. Replace the oil feed pipe. Put another copper washer on every feed pipe. Cautiously change the dome headed nuts and tighten. This will pull the rocker spindle even much more tightly into the rocker box. You should not more than tighten.
Reset the valve clearances. Eight-thousandths of an inch for the inlet side, and 6 thousandths of an inch for the exhaust. It is strange to have the inlet rocker hole much larger than the exhaust, but this is suitable for the T140 motor owing to its camshaft profiles. Change the rocker box gaskets. A smear of gasket sealant will not likely hurt. Never overdo it. Tighten the rocker box inspection handles (incrementally, please).
Examine that everything is as it was. Start out the engine, assure that the oil pressure light goes out, inspect for leaks, and experience the bicycle to heat totally. If, right after a time period of a several days or months, the spindles aren’t leaking, they are most likely set. But if one or both even now leak, you’ll have to check out once more. It should to function each and every time, but it won’t. These are old bikes and need to have a minor fussing.
If you have persistent difficulties listed here, you can check out removing equally rocker packing containers and stripping fully. Then you might test machining a pretty small 45-degree bevel (or thereabouts) on the still left facet of each and every rocker box the place the spindle is drawn in. This bevel can enable reduce the O-rings from snagging on reassembly. Just a millimetre or two will suffice.
Generally get the best O-rings you can from a trustworthy resource. Don’t bother making an attempt any kind of resin or sealant close to the O-rings. It not often, if ever, performs. Try to remember that the spindles you should not actually spin. As a substitute, the rockers inside of the rockerboxes pivot all-around the spindle. The object of the exercising is to feed those people new O-rings gently into the rocker packing containers. Appear at the problem in engineering conditions. By no means power anything in this spot. It shouldn’t need to have it. Just be sluggish and methodical. If you want to check out the spindle housing for use, start off the motor and set a gloved finger from every spindle in transform (still left hand aspect, and then proper hand facet).
If the spindles are bouncing up and down, or shifting at all, they have to have replacing. Often this movement is obviously obvious. If you like, you can absolutely take out just about every rockerbox and replace the O-rings on the bench. But it just isn’t important if you very first take out the valve/rocker-load and use the distinctive instrument with a good deal of oil.