Moderator DirtyDT Posted May 23, 2009 Moderator Share Posted May 23, 2009 Hi all, I have taken the oil pump off of my DT as part of replacing the 4 two stroke oil pipes. 2 to the pump and 2 away from the pump. I have bled the oil pump as advised by OG in a previous thread. I am pumping the kick start over with my hand with the plug out and the oil is feeding from the pump to the junction that is pressed into the crankcase. I can see this as I brought the clear oil pipe. Even if I hold the oil pump open and "Hand kick" the bike over, the oil is very slow going towards the carb. I have got to about 1 inch from the junction and then there is about another 6 inches of pipe before the oil his the carb. Rather than keep pumping the kick start with my hand would it be better to mix a pint of premix so it runs safely until the oil is fed to the carb? If this is recommended what ratio should I use? Thanks Link to comment Share on other sites More sharing options...
wild foamy Posted May 23, 2009 Share Posted May 23, 2009 i prefer to run a 30:1 premix after a rebuild, or on the Jawa i run 30:1 anyway so for every one liter of petrol you mix in 30ml of oil. or enter the amount you want to mix with into this calculator and it will tell you the required amount of two stroke oil http://www.csgnetwork.com/oilfuelcalc.html honestly it wont take long to bleed through to the carb once the engine is running, and aslong as you arent thrashing the bike around the lack of two stroke oil wouldnt be harmfull, its best just to start the engine up, let it idle and turn the oil pump to its maximum stroke by hand Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 23, 2009 Author Moderator Share Posted May 23, 2009 Cheers WF, I am not riding it but want to get it running OK. I have taken off so much, cleaned and rebuilt them that I will be idling it while I adjust the tick over, look for leaks etc. I will get as close to that as possible but I am going to put a pint of petrol in and add the two stroke. It's a shame that 2 stroke does not smell like it did in the good old days. Link to comment Share on other sites More sharing options...
JimR Posted May 23, 2009 Share Posted May 23, 2009 Hi all, I have taken the oil pump off of my DT as part of replacing the 4 two stroke oil pipes. 2 to the pump and 2 away from the pump. I have bled the oil pump as advised by OG in a previous thread. I am pumping the kick start over with my hand with the plug out and the oil is feeding from the pump to the junction that is pressed into the crankcase. I can see this as I brought the clear oil pipe. Even if I hold the oil pump open and "Hand kick" the bike over, the oil is very slow going towards the carb. I have got to about 1 inch from the junction and then there is about another 6 inches of pipe before the oil his the carb. Rather than keep pumping the kick start with my hand would it be better to mix a pint of premix so it runs safely until the oil is fed to the carb? If this is recommended what ratio should I use? Thanks Hi DirtyDT, there is no need to do that .. if the pump is bled to the bleed screw when the engine is running the oil will run up the small bore pipe quickly but to give peice of mind add some oil to the petrol tank in order for the process to happen. There is small chance you will be able to work out if the oil pump is working by using the kickstart (with a running engine & a good pump the oil will be to the carb in seconds). You may want to add 25:1/50:1 ratio to the fuel tank as when the pump kicks in the engine may be 'over oiled' Regards Jim Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 23, 2009 Author Moderator Share Posted May 23, 2009 Cheers JimR, I was going to add a splash of 2 stroke to the to the tank. By just putting in a small amount of fuel I am looking to get out of the over oil problem. Cheers. Link to comment Share on other sites More sharing options...
JimR Posted May 23, 2009 Share Posted May 23, 2009 the amount you want to mix with into this calculator and it will tell you the required amount of two stroke oil http://www.csgnetwork.com/oilfuelcalc.html honestly it wont take long to bleed through to the carb once the engine is running, and aslong as you arent thrashing the bike around the lack of two stroke oil wouldnt be harmfull, its best just to start the engine up, let it idle and turn the oil pump to its maximum stroke by hand Hi WF, I would guess that using a calculator to work out is a bit naff ... in the flintstone days the oil was added to the fuel via the machine/pump at the fuel station .. there was very little info to tell u if the machine/pump had any oil in it or was calibrated correctly so you may go to one fuel station & switch the pump to 50:1 and get delivered 0 oil .. a few mins later an engine lock up !!! or you may get double the oil and end up with a whisker !!! perhaps it would be also good practice to check the minimum pump stroke rather than pushing the cable wheel back to deliver more oil than is required. Regards Jim Link to comment Share on other sites More sharing options...
wild foamy Posted May 23, 2009 Share Posted May 23, 2009 i was refering to turning the pump to its maximum stroke to help the oil get to the carb quicker annd hence reduce the duration fo time for the engine to run un-oiled. Link to comment Share on other sites More sharing options...
JimR Posted May 23, 2009 Share Posted May 23, 2009 i was refering to turning the pump to its maximum stroke to help the oil get to the carb quicker annd hence reduce the duration fo time for the engine to run un-oiled. Hi WF, on commision (new bike out of the box) there was no need to hold the thing back ... it was true in the mid 70's the extra wheel added to the pump (on your pump its a big black cover to the pumps left as you look at it) and the process was to turn the back gear (in order to prime the pump and small bore pipes) to ensure oil was delivered to the engine. With the introduction of High Speed pumps (the blank on the back of the pump) it was no longer a requirement to bleed the pump in the old fashioned way .. just make sure the air is out the bleed screw & run the motor Regards Jim Link to comment Share on other sites More sharing options...
Moderator mervin Posted May 23, 2009 Moderator Share Posted May 23, 2009 i usually hold the pump wide open with the cable to prime it with engine ticking over. if you want the smell a small splash of castrol R in the petrol tank will do the trick and cause no harm and give yo the smell merv Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 23, 2009 Author Moderator Share Posted May 23, 2009 Thanks guys, I do not have any engine oil in it at the moment. Too nice to go to Halfords. I asked the other half to push me around the garden on it (I was going to put it in gear) But she declined. Tut! Link to comment Share on other sites More sharing options...
nayruf Posted May 24, 2009 Share Posted May 24, 2009 Thanks guys, I do not have any engine oil in it at the moment. Too nice to go to Halfords. I asked the other half to push me around the garden on it (I was going to put it in gear) But she declined. Tut! Having just rebuilt my twin shock and fitted a new OEM oil pump, I did as suggested previously held the pump on max stroke and let the engine tick over till I was sure that the oil had got to the manifold, My reasoning was that lubricating oil from the rebuild was already present in the crank cases and bore so little extra wear would take place. 500 miles later all is still ok Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 27, 2009 Author Moderator Share Posted May 27, 2009 Hi all, Just a quick update. I got the "big one" tail pipe yesterday. I one I ordered from MandP on 17th of the month! So happy as larry and with the sun still shining I filled the bike with engine oil and bolted on the new expansion pipe and tail pipe. a pint of petrol with a spash of 2 stroke and I was ready to go. As the carb had been stripped and rebuilt I splashed a little fuel in the spark plug hole and gave it a couple of kicks. It fired up and died having used the fuel in the cylinder. A few kicks later and it was running. A quick adjust of the tickover screw and the choke in and it was ticking over nicely. I checked the 2 stroke fuel line and it was full of oil. Into gear and out with the cluch and it would not pull. A quick clutch adjustment and around the garden I went. As it was a non runnner I was more than happy so off the bike with it engine running and I notice that there is exhaust fumes coming from the front of the tail pipe. A quick look and placing my hand over the front of the can, It is blowing where the pipe meets the can. So a bit peeved. An email to MandP and a phone call this morning and they are collecting the pipe tomorrow. I will let you know how it goes. Link to comment Share on other sites More sharing options...
JimR Posted May 27, 2009 Share Posted May 27, 2009 Hi all, Just a quick update. I got the "big one" tail pipe yesterday. I one I ordered from MandP on 17th of the month! So happy as larry and with the sun still shining I filled the bike with engine oil and bolted on the new expansion pipe and tail pipe. a pint of petrol with a spash of 2 stroke and I was ready to go. As the carb had been stripped and rebuilt I splashed a little fuel in the spark plug hole and gave it a couple of kicks. It fired up and died having used the fuel in the cylinder. A few kicks later and it was running. A quick adjust of the tickover screw and the choke in and it was ticking over nicely. I checked the 2 stroke fuel line and it was full of oil. Into gear and out with the cluch and it would not pull. A quick clutch adjustment and around the garden I went. As it was a non runnner I was more than happy so off the bike with it engine running and I notice that there is exhaust fumes coming from the front of the tail pipe. A quick look and placing my hand over the front of the can, It is blowing where the pipe meets the can. So a bit peeved. An email to MandP and a phone call this morning and they are collecting the pipe tomorrow. I will let you know how it goes. Hi DirtyDT, I guess the tail pipe was not a good fit to the exhaust system then ? but if the exhaust is a different brew to the tail pipe there is a chance there may be some difference in their sizes and the replacement will leak also Regards Jim Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 27, 2009 Author Moderator Share Posted May 27, 2009 Hi JimR, The two parts were sourced from different suppliers but were both "Big one's". They fitted on the bike and together perfectly however the picture shows where it was blowing. Not through the pop rivets but between the pipe and can. Link to comment Share on other sites More sharing options...
JimR Posted May 27, 2009 Share Posted May 27, 2009 Hi JimR, The two parts were sourced from different suppliers but were both "Big one's". They fitted on the bike and together perfectly however the picture shows where it was blowing. Not through the pop rivets but between the pipe and can. Oh OK, I guess there is a seal problem there .... send it back & I would guess the replacment will work fine .... but if it does not just check out the gaskit in the rear pipe as there may be a production problem Regards Jim Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 27, 2009 Author Moderator Share Posted May 27, 2009 Parcel farce are collecting it tomorrow to go back. I could always put a little gungum in the slot if it happens with the new one over time as this is a one piece tail pipe and apart from drilling out the rivets and sealing there is not a lot I can do. I am suprised that there is such a little choice of exhausts, especially seeing how many DTs are still around. There is a guy on ebay at the moment selling a batch of 5 as one lot. Luck b*stard. Link to comment Share on other sites More sharing options...
JimR Posted May 27, 2009 Share Posted May 27, 2009 Parcel farce are collecting it tomorrow to go back. I could always put a little gungum in the slot if it happens with the new one over time as this is a one piece tail pipe and apart from drilling out the rivets and sealing there is not a lot I can do. I am suprised that there is such a little choice of exhausts, especially seeing how many DTs are still around. There is a guy on ebay at the moment selling a batch of 5 as one lot. Luck b*stard. Hi, don't forget that bike is now old ... and there be not enough demand to produce parts ... I have problems sourcing parts for my FS1 and to a degree over the years there were far more FS1's on the road over DT175mx's so perhaps the manufacturers do not have the market to warrent the production run ! Regards Jim Link to comment Share on other sites More sharing options...
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