brucey Posted June 29, 2019 Report Share Posted June 29, 2019 I continue to have problems with the Cub I built from all my spare parts for my Son to ride. It has a habit of leaking the contents of the Sammy Miller type top tube oil tank onto his shed floor!. The first time this happened I replaced the steel balls in the later type oil pump for a plastic ball and spring upgrade kit from UPB. But after sitting in his shed for a few months, it just did it again. I drained the remaining oil from the engine sump and got about 250 to 300 ml out. The total capacity is around 750 to 800 ml with the external oil filter and oil tank filled. I did notice the jubilee clip on the oil feed pipe to the bottom of the engine wasn't as tight as it could have been which may have caused the semi synthetic oil to leak out as the weather got warmer. My question is; Would there have been more oil in the sump if the oil was making its way past the oil pump and wet sumping? If it was wet sumping, where would the oil come out? The engine turned over fine when I took the spark plug out and pushed it down the road. I'm going to fill it up again, tighten the Jubilee clip and see what happens ? Does anyone else have this problem with their Cub? Bruce. Quote Link to comment Share on other sites More sharing options...
naichuff Posted June 29, 2019 Report Share Posted June 29, 2019 I use a Miller oil tank on both Cubs I did not use the plastic pipe to feed the engine but rubber oil hose to feed it as I cut the plastic pipe the wrong length on the first engine But when doing the second one used the plastic hose Like you it leaked at the gearbox where it fits on to the copper pipes So the was fitted with rubber pipe also The plastic pipe is a loose fit on the mettle pipe even with hose clip tight 1 Quote Link to comment Share on other sites More sharing options...
brucey Posted June 29, 2019 Author Report Share Posted June 29, 2019 48 minutes ago, naichuff said: I use a Miller oil tank on both Cubs I did not use the plastic pipe to feed the engine but rubber oil hose to feed it as I cut the plastic pipe the wrong length on the first engine But when doing the second one used the plastic hose Like you it leaked at the gearbox where it fits on to the copper pipes So the was fitted with rubber pipe also The plastic pipe is a loose fit on the mettle pipe even with hose clip tight Thanks for your reply Naichuff. I will leave the sump guard off for a bit and keep an eye on the feed pipe at the engine end. The reinforced plastic pipe is at least 5 years old but still flexible. Quote Link to comment Share on other sites More sharing options...
pre65wobbler Posted June 29, 2019 Report Share Posted June 29, 2019 Flog it and get a C15 !! 1 Quote Link to comment Share on other sites More sharing options...
brucey Posted June 29, 2019 Author Report Share Posted June 29, 2019 3 hours ago, pre65wobbler said: Flog it and get a C15 !! Or upgrade it Joan ? Trouble is it's my spare Cub so I don't get a chance to ride it and fettle it as much as I should. I filled it up with oil and ran it this evening. I have oil leaking from the crank case to gearbox cover, top push rod tube (straight onto the exhaust) timed vent in the cam bush and gear selector (even though it has the o ring plate fitted). Looks like I'm going to need to use more sealant next time! I think I'll take the opportunity to fit close ratio 1st and 2nd gears and replace the 16T trials primary drive with a standard 19? tooth sprocket as it does make a lot of noise. Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted June 30, 2019 Report Share Posted June 30, 2019 (edited) Brucey do you have a 16t crank sprocket with tensioner is it that which makes a noise, is the noise inherent due to the tensioner or does the amount of free play make a difference my bike also rumbles from the tensioner area might the noise be due to wear on the main bearings? Edited June 30, 2019 by trialsrfun Quote Link to comment Share on other sites More sharing options...
brucey Posted June 30, 2019 Author Report Share Posted June 30, 2019 10 hours ago, trialsrfun said: Brucey do you have a 16t crank sprocket with tensioner is it that which makes a noise, is the noise inherent due to the tensioner or does the amount of free play make a difference my bike also rumbles from the tensioner area might the noise be due to wear on the main bearings? Trialsfun, The noise is almost a mechanical whine. I have checked the tension several times and got it about as good as it's going to get but the primary drive duplex chain seems to take quite a tortuous route with such a small drive sprocket. I used a standard set up with close ratio gearing before which was much quieter. Time to note all the faults, pull the engine apart and put it back together properly this time ? I have fitted a diaphragm clutch and belt primary drive to my Armac Cub and it is amazing! Bruce. Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted June 30, 2019 Report Share Posted June 30, 2019 (edited) 48 minutes ago, brucey said: Trialsfun, The noise is almost a mechanical whine. I have checked the tension several times and got it about as good as it's going to get but the primary drive duplex chain seems to take quite a tortuous route with such a small drive sprocket. I used a standard set up with close ratio gearing before which was much quieter. Time to note all the faults, pull the engine apart and put it back together properly this time ? I have fitted a diaphragm clutch and belt primary drive to my Armac Cub and it is amazing! Bruce. I have the UPB thin clutch plates with 16t engine sprocket and tensioner. I seem to remember someone saying the belt drive pulley being about 17t equivalent on the PK belt drive conversion. By comparison I have a Villiers engined bike fitted with a Villiers Services 17t sprocket (similar pitch primary chain to Cub but single row) and nylon tensioner running with complete satisfaction which made me question if the mains are to blame for the noise made by the Triumph Cub. Edited June 30, 2019 by trialsrfun Quote Link to comment Share on other sites More sharing options...
brucey Posted June 30, 2019 Author Report Share Posted June 30, 2019 2 hours ago, trialsrfun said: I have the UPB thin clutch plates with 16t engine sprocket and tensioner. I seem to remember someone saying the belt drive pulley being about 17t equivalent on the PK belt drive conversion. By comparison I have a Villiers engined bike fitted with a Villiers Services 17t sprocket (similar pitch primary chain to Cub but single row) and nylon tensioner running with complete satisfaction which made me question if the mains are to blame for the noise made by the Triumph Cub. I too am running the UPB additional plate clutch in this Cub. The mains were replaced when I rebuilt the engine from all my spare parts only a couple of trials ago but I'll check them as I'm currently in the process of removing and stripping it to cure the oil leaks. From an engineering point of view, I think I prefer the standard (larger)duplex primary drive sprocket. It should also make the bike easier to start but I will have to get the close ratio 1st & 2nd gears from somewhere. As well as the trials ratio's, I would like to fit a side points 'R' Cam but am having extreme difficulty in finding one! Quote Link to comment Share on other sites More sharing options...
brucey Posted July 6, 2019 Author Report Share Posted July 6, 2019 On a slightly different note, I have stripped the engine and measured the crank alignment near the ignition rotor key way. It appears to be running out around 0.3mm (about 10 thou) total. I have been advised this is ok. The ignition rotor doesn't touch the stator (I recon about 0.5mm clearance). although it does 'wobble' a little bit ? Has anyone else measured the crank run out on their engine? Bruce. Quote Link to comment Share on other sites More sharing options...
thai-ty Posted July 31, 2019 Report Share Posted July 31, 2019 (edited) 1. Again no Cub expert, but ten thou seems a lot. 2. Having sold up my Triumph shop in 2003, i am not familiar with a plastic ball oil pump kit, but it just sounds so wrong. 3. If you are getting wet sumping with a Triumph type plunger oil pump, it can only be balls not seating on the seat. Normally dirt. However a light plastic ball again just does not seem right. 4. By the sounds of things, the whole thing needs to come apart and be blueprinted. Regards. Edit, on our race or high performance twins we always ditched the timed breather, and ran a proper large bore non timed breather pipe from either the timing cover, primary cover or c/case. We also ran top end breathers from both r/boxes. None of our engines had oiling problems or oil leaks. Again, these were all 650-750-830 twins. Edited July 31, 2019 by thai-ty 1 Quote Link to comment Share on other sites More sharing options...
old bones Posted August 28, 2019 Report Share Posted August 28, 2019 Brucey, I am also having problems with the oil pump on my Cub, I had an LF Harriss plunger type fitted and after a short time it started to fill up with oil whilst running, the oil tank was draining and not returning so took it apart to clean the pump hoping to find a problem but none could be found. Put it back together and using the kickstart to see if oil was returning and it was ,so put it back in the garage. After about 4 days I noticed oil on the floor so stripped it down again and inspected the pump... nothing found. I left the cover off and the pump connected to a full tank of oil and found it was dripping from the supply plunger on a new pump with only a short time in use!! I am still trying to determine if the pump is at fault or something else I could be missing. So check the pump with it in place and see if your problem is the same as mine. Old Bones Quote Link to comment Share on other sites More sharing options...
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