Well-sorted Bonnie there Dave , I thought you must be in England or somewhere-else when I was watching your rebuild video . Being able to quickly source-pistons wasn't something I expected in NZ . I've owned a few-Triumphs, Nortons etc , including a 79-Bonny with 12k original-miles . These-days I'm riding a Yamaha and a W650 (Kawasaki ) , both great-machines , lovely winding-roads over Hunterville-way ...another Dave
Hi Dave, Ive sealed my crankcase to run a dry belt primary. I've vented it from the plug behind the cylinder out behind the rear gaurd to catch can, its not very successful as throws out too much oil. Would this rocker cover solution be enough to vent a sealed crankcase? I would have assumed I would need a bottom end vent somewhere - I'm no mechanic 😅. Thanks in advance!
Hi so lets first understand what's going on with your bike. I understand you have fitted a belt drive. To fit the belt you will have closed off the three equalisation holes in the bottom of the primary case into the crank case. YES / NO.....?? (This is not a vent only a point to allow oil to flow from one side to the other to lubricate the triplex chain). Second im guessing again,,, that you have closed off the crankcase breather at the top of the Primary case at the back. That connects to a vent pipe that runs either to the back of the bike with a T140v,,,, or into the air breather box on the E and newer. YES/NO?? Then you have removed the plug and used the timing plug in between the carbs and fitted some form of pipe as a vent pipe for the crankcase and have linked that to the exiting breather pipes. YES/NO?? Before we can go further its very important I have a clear picture and my information from you is correct,,,, or please advise me on further... I can only then suggest a workable solution for you???
All of your assumptions are 100% correct. Crankshaft seal Inserted, 3 holes sealed with jb weld, closed off breather from back of primary, used existing hose that ran from primary to back of mud gaurd to connect to timing plug that i drilled out and brazed fitting onto. It is not an E model no air box. The 2 options i have seen that I have left is to drill and tap a hole in the top of the timing cover or to go from the front motor mount which would need me to pull the motor apart which If i ever want the bike to work again someone else would need to do. Now ive seen this video this looks like a prettier fix than the timing cover job if it would be enough to vent the crankcase. P.s. i would have never mucked with it i bought sight unseen and didnt check the primary until i broke down on it and he had a wet red belt set up which i changed to a dry BNR clutch set up.. where my troubles began.
@@spencer8503 Hiya well considering you say you are no mechanic then your doing pretty good. Over the coming years I would recommend collecting all the parts second hand for the old triplex chain set up, as that will out live the belt set up by a very long way and give you a lot less trouble. Its very very important to check for wear on belt drives as a broken one can destroy your engine. Read the manufactures recommendations on the belt life... One point of caution is you may or not know about the wet belt to dry belt conversions. They wet belt ones are like that so that the hub on the clutch is lubricated in the same way the triplex chain hub is lubricated. Simply changing to a dry belt dependant on the make you have can mean you need to change the bearing on the clutch also. Anyway I can chat about that stuff forever lol...As you have the belt drive on already I will presume you have sorted that bit out and we shall go on from there. Firstly and understanding you MUST reduce the crankcase pressure or you will blow all your oil seals if you haven't done already. I suspect your rocker boxes and o rings are already leaking oil, but that will mostly come right after you have finished doing the breather upgrade. 1. Your new vent you have from the timing plug will work perfectly but needs a bit more work. First it needs disconnecting from the old funny shaped breather pipe that runs to the back of the bike. Seal up that connection part on the old funny shaped breather pipe up with a plug. That old breather pipe should be connected still to the frame breather pipe. 2. Now check the frame breather,,, running from the breather pipe just below the steering head along under the tank is still connected to the old breather pipe connected behind the primary side air cleaner. Its hard to see it unless you take the tank off. 3. Now fit a new re routed 6mm or 8mm pipe that will be routed rising up from the new crankcase vent connection you made, running almost vertically between the carbs and route it along under the seat same as I have done. 4. Cut this new vent pipe high up at the point where the new vent pipe curves up under the seat and fit a brass Y connector. Available from any DIY store. 5. Cut the new vent pipe again under the seat and fit a 5psi spring loaded 6mm or 8mm one way valve under the seat as in my video. THIS ONE WAY VALVE IS VERY VERY IMPORTANT.. Available from most plumbing stores for about $10 and then out to the back of the bike. This valve prevents moist air from being drawn into the engine and actually depressurises the crankcase when in operation. 6. Fit securely a 3mm dia plastic restrictor about 10mm long inside the new vent pipe you have made at the new timing plug vent you made between the carbs. This restrictor helps reduce and almost stops the oil throw you are getting from that vent position you are using. This oil throw is from the crankshaft as it rotates but still allows the lower crankcase pressure to vent. Ensure this plastic restrictor is fitted securely and cannot fall into the engine. 7. So now you should have a connection from the new timing plug you made that runs on its own vent pipe running almost vertically from your new plug up above the carbs to the brass Y connector then along under the seat to the one way valve, and then out to the back of the bike as in my video. 8. Now we are at where my video starts -----Remove the Rocker box cover and fit the pipe as I have shown in my video and connect that to your new pipe at the Y junction high up between your carbs. 9. Start the bike and put your finger over your new vent pipe at the back of the bike. You will feel it pulsing. That's perfect and you wont need a collector can on the end of the pipe as any oil in the lines gets sucked back from the one way valve. 10. If you find with use that you are still using too much oil just fit a 3mm restrictor inside your new rocker vent pipe.(Normal oil usage even on a brand new Bonnie is about 0.5ltrs per 1000 miles.) 11. I would recommend disconnecting the new breather lines every 10,000 miles and just give them a cleanout and check the one way valve is working ok. 12 Clean your engine and now check your bike for oil leaks. Replace any seals that have blown prior to you fitting the new breathers. You will be oil free after that. This is a bit drawn out I know but to do the job is really pretty simple and will only takes a couple of hrs and only cost a few bucks. Happy to answer any more questions you may have. Have fun and ride safe...🙂
Dave this has been incredibly helpful and makes a lot of sense. I can't thank you enough! Looking forward to following this to a T. You're a good man, thanks again.
Well-sorted Bonnie there Dave , I thought you must be in England or somewhere-else when I was watching your rebuild video . Being able to quickly source-pistons wasn't something I expected in NZ . I've owned a few-Triumphs, Nortons etc , including a 79-Bonny with 12k original-miles . These-days I'm riding a Yamaha and a W650 (Kawasaki ) , both great-machines , lovely winding-roads over Hunterville-way ...another Dave
Hi mate yes we have a very good supply line to keep us all on the road out here out in the colony's lol. Ride safe.
Looks good
Works great
Hi Dave, Ive sealed my crankcase to run a dry belt primary. I've vented it from the plug behind the cylinder out behind the rear gaurd to catch can, its not very successful as throws out too much oil. Would this rocker cover solution be enough to vent a sealed crankcase? I would have assumed I would need a bottom end vent somewhere - I'm no mechanic 😅. Thanks in advance!
Hi so lets first understand what's going on with your bike. I understand you have fitted a belt drive. To fit the belt you will have closed off the three equalisation holes in the bottom of the primary case into the crank case. YES / NO.....?? (This is not a vent only a point to allow oil to flow from one side to the other to lubricate the triplex chain). Second im guessing again,,, that you have closed off the crankcase breather at the top of the Primary case at the back. That connects to a vent pipe that runs either to the back of the bike with a T140v,,,, or into the air breather box on the E and newer. YES/NO?? Then you have removed the plug and used the timing plug in between the carbs and fitted some form of pipe as a vent pipe for the crankcase and have linked that to the exiting breather pipes. YES/NO?? Before we can go further its very important I have a clear picture and my information from you is correct,,,, or please advise me on further... I can only then suggest a workable solution for you???
All of your assumptions are 100% correct. Crankshaft seal Inserted, 3 holes sealed with jb weld, closed off breather from back of primary, used existing hose that ran from primary to back of mud gaurd to connect to timing plug that i drilled out and brazed fitting onto. It is not an E model no air box. The 2 options i have seen that I have left is to drill and tap a hole in the top of the timing cover or to go from the front motor mount which would need me to pull the motor apart which If i ever want the bike to work again someone else would need to do. Now ive seen this video this looks like a prettier fix than the timing cover job if it would be enough to vent the crankcase.
P.s. i would have never mucked with it i bought sight unseen and didnt check the primary until i broke down on it and he had a wet red belt set up which i changed to a dry BNR clutch set up.. where my troubles began.
@@spencer8503 Hiya well considering you say you are no mechanic then your doing pretty good.
Over the coming years I would recommend collecting all the parts second hand for the old triplex chain set up, as that will out live the belt set up by a very long way and give you a lot less trouble. Its very very important to check for wear on belt drives as a broken one can destroy your engine. Read the manufactures recommendations on the belt life...
One point of caution is you may or not know about the wet belt to dry belt conversions. They wet belt ones are like that so that the hub on the clutch is lubricated in the same way the triplex chain hub is lubricated. Simply changing to a dry belt dependant on the make you have can mean you need to change the bearing on the clutch also.
Anyway I can chat about that stuff forever lol...As you have the belt drive on already I will presume you have sorted that bit out and we shall go on from there.
Firstly and understanding you MUST reduce the crankcase pressure or you will blow all your oil seals if you haven't done already. I suspect your rocker boxes and o rings are already leaking oil, but that will mostly come right after you have finished doing the breather upgrade.
1. Your new vent you have from the timing plug will work perfectly but needs a bit more work. First it needs disconnecting from the old funny shaped breather pipe that runs to the back of the bike. Seal up that connection part on the old funny shaped breather pipe up with a plug. That old breather pipe should be connected still to the frame breather pipe.
2. Now check the frame breather,,, running from the breather pipe just below the steering head along under the tank is still connected to the old breather pipe connected behind the primary side air cleaner. Its hard to see it unless you take the tank off.
3. Now fit a new re routed 6mm or 8mm pipe that will be routed rising up from the new crankcase vent connection you made, running almost vertically between the carbs and route it along under the seat same as I have done.
4. Cut this new vent pipe high up at the point where the new vent pipe curves up under the seat and fit a brass Y connector. Available from any DIY store.
5. Cut the new vent pipe again under the seat and fit a 5psi spring loaded 6mm or 8mm one way valve under the seat as in my video. THIS ONE WAY VALVE IS VERY VERY IMPORTANT.. Available from most plumbing stores for about $10 and then out to the back of the bike. This valve prevents moist air from being drawn into the engine and actually depressurises the crankcase when in operation.
6. Fit securely a 3mm dia plastic restrictor about 10mm long inside the new vent pipe you have made at the new timing plug vent you made between the carbs. This restrictor helps reduce and almost stops the oil throw you are getting from that vent position you are using. This oil throw is from the crankshaft as it rotates but still allows the lower crankcase pressure to vent. Ensure this plastic restrictor is fitted securely and cannot fall into the engine.
7. So now you should have a connection from the new timing plug you made that runs on its own vent pipe running almost vertically from your new plug up above the carbs to the brass Y connector then along under the seat to the one way valve, and then out to the back of the bike as in my video.
8. Now we are at where my video starts -----Remove the Rocker box cover and fit the pipe as I have shown in my video and connect that to your new pipe at the Y junction high up between your carbs.
9. Start the bike and put your finger over your new vent pipe at the back of the bike. You will feel it pulsing. That's perfect and you wont need a collector can on the end of the pipe as any oil in the lines gets sucked back from the one way valve.
10. If you find with use that you are still using too much oil just fit a 3mm restrictor inside your new rocker vent pipe.(Normal oil usage even on a brand new Bonnie is about 0.5ltrs per 1000 miles.)
11. I would recommend disconnecting the new breather lines every 10,000 miles and just give them a cleanout and check the one way valve is working ok.
12 Clean your engine and now check your bike for oil leaks. Replace any seals that have blown prior to you fitting the new breathers. You will be oil free after that.
This is a bit drawn out I know but to do the job is really pretty simple and will only takes a couple of hrs and only cost a few bucks.
Happy to answer any more questions you may have.
Have fun and ride safe...🙂
Dave this has been incredibly helpful and makes a lot of sense. I can't thank you enough! Looking forward to following this to a T. You're a good man, thanks again.
@@spencer8503 Your welcome😀