Vintage Dirt Bike Q & A

i hooked up a battery and did the switch test.




works great!

the wires to the speedometer were cut off sometime before i got the unit.i am repairing the damage by soldering in a new section.
making a mechanical connection.


then soldering it.


then apply the heat shrink tubing.


then plugged it in to the harness.

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(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

i made this video before i got the cylinder and other parts needed and before i got the engine running, i wired in the battery into the headlight circuit for testing purposes.

click the image to play the video.


i located a NOS speedo trip knob because the speedo i have has the knob missing.the knob i got had no screw though and this is a pic of the parts i needed.


i dug into some small metric screws until i found one that would work.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

i decided to peel off the stickers on the forks,quite a layer of stickers was found and evidence this bike was registered in 1977 in Oklahoma.

it says 1978 and is good until the expiration date in 1978 but was good for the 1977 year.




i had to buff it off on a buffing wheel and it looked better but not perfect,this is going to be a rider and it is good enough for that.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

to restore the color you use a heat gun,you heat it until it looks like wet paint then move to another area.


after a bit more work.


this is the best i can get out of her.








here is a video of the heat process being done,just click this image to play the video.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

now to work on the brake panels.first the rear brake.
this lever as you can see is quite bent up.




i found a piece of flat bar stock the same width as the opening and used that to straighten the bent parts.


the finished product.


now to work on this very neglected part.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

after cleaning off some rust.


this had a incorrect 1/4 bolt and nut on it but i had a correct 6 mm bolt and nut for it.i also trial fitted it on the refurbished lever.




now to repaint this.


i stripped off the old paint.


then i gave it a coat of fresh satin black paint.


after the paint dried it was ready for reassembly.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

i gave the actuating rod a coat of grease.


the finished part ready to put on.


the same process was done on the front brake panel.first to disassemble and clean for painting.


when i reassembled the panel the speedo drive clutch was destroyed because the unit was froze up.i replaced that with a new part after freeing it up and cleaning the associated parts.


ready to go.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

as the time for the initial start up got near i got a new K&N air filter for it.




to oil the filter i used the spray oil K&N makes to coat the filter with.


ready to install.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

i also got a new SLA type battery to put in.




the battery installed and ready to go.

i ran it with the stock 22.5 pilot jet and all i had was main jets and i already replaced the stock 140 main with a 180 main jet.

so i ordered a pilot jet for a Yamaha Banshee which is a 25 pilot jet from the same supplier i ordered some other small parts from.


here i am changing the 22.5 pilot to a 25 pilot jet,it is still a touch lean so next month i am ordering a 27.5 and a 30 pilot jet.


how to get the little guy out with the carb on the bike? with a wooden tooth pick.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

i got another tank for this bike and i am going to use it as a model for decal placement as i plan to either repaint the yellow tank or get one that has fewer dents to fix.

for now i am using it,i fitted it with a new petcock and new vent and fuel hoses.


the petcock is different than the original but other than that it fits and works great.


5 videos,first 2 is the first start up of the fresh engine and 3 more videos with the 25 pilot installed and running on the fuel tank,the first video i am using a Motion Pro portable tank.
despite saying it was fat as in rich it is really too lean.


this video i got it to idle more or less.


cold engine in this video


hot restart


another video,a cold start with the 25 pilot installed.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

another pair of videos of two different electrical tests.

there is one of the turn signal operation and another with the tail/brake light being tested.

i only had 3 units with the correct 6 volt 21 watt bulbs and a 6/12 volt test light.
i wired in the test light to load the circuit so it would light the indicator light and without the test light it tried to flash all 3 turn signal lamps and not light up the indicator.

without the right bulbs they will not flash at all and this is why it would only flash in 1 direction,i plan on picking up a set of 4 reproduction lamps for it.


this one is the brake/tail light operation.i need to repaint the tail light bracket and get the mounting hardware as i do not have that yet.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

with the porting and mild engine work done,here is a couple of videos that inspired this project i have going.these do pack a punch when treated right.

this bike was built by BVH racing developments in Africa.he is using the stock pipe and a gutted silencer and on mine i will mod the stock pipe and use a FMF Turbine core 2 universal silencer.the porting on my bike is of a higher spec than the one in this video.
these videos are of a 1978 DT175 like the one i am building.




this is a link to the bike in the videos,i agree with him on the assessment the stock ports are crap.
http://www.extreme2strokes.com/showthre ... 90#pid3790

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

the wheel guy got me fixed up with some beautifully done rim assemblies.it may be a while before i can get them though.


i also got the new grips today and put them on.








i got the mounting hardware for the tail light coming and it should be here this weekend,i painted the bracket but i had not done much with the light other than getting it to work.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

i got the jets,wheel bearings and the tail light mounting parts in this morning.


i did not get parts 12,14,17 and 18 but i know a store has part 12 in stock as it is no longer available but the rest is still available from Yamaha however.


here is a short video of the cold engine being started and a lighting test.click the image to play the video.i rigged up the tail light mounting due to the missing pieces for now.

_________________
(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!