racerd
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Posts posted by racerd
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Right iv had it all apart piston is fecked but what i wanted to ask is:
Is there allowed to be any sideways action in the crank?
if not my big end is gone to
do you mean the crank moves side ways in the main bearings if you do then the crank journals are worn also what colour is the firing tip on the spark plug
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whats the forum? i have just gotten a 1980 DT 125 and im sure its the carba but would like the specs on a rebuild of it ..
thanks loads jimbo
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I am picking up a brand new 58 plate fazer on monday and have been told that the engine is a slightly de tuned R6 engine..
Bet you know what i am gonna ask lol
Can you get the engine tuned to an R6 standard???
How???
How much???
Where
Cheers Gaz
would the r6 parts fit onto your fazer
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QUOTE (yamafun @ Dec 30 2006, 08:26 AM) *
MY 1979 YAMAHA DT175 HAS 22 HORSEPOWER AT 12000 RPM. MAX RPM IS 13000RPM. DYNO TESTED USING A DYNOJET 2 WHEEL AUTOMOTIVE DYNO. USED ONLY ONE ROLLER INSTEAD OF BOTH. ORIGINAL HORSEPOWER WAS APPROX 14 HP AT THE WHEEL AT 7000 RPM. MODIFICATIONS ARE THE FOLLOWING:
IT175 CYLINDERHEAD MODIFIED ON A LATHE; SHAVED CYLINDERHEAD BUT MADE COMBUSTION CHAMBER WIDER. OCTANE USED 91 OCTANE. USED 1977 IT175 CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; MAIN AND IDLE JETS. K&N AIR FILTER. STOCK CYLINDERHEAD BORED TO FIRST OVER, PORTED TO SPECS OF 1977 IT175 PORTS SIZE. EXPANSION CHAMBER FROM 1991 HONDA CR125 MODIFIED TO FIT. MUFFLER PROCIRCUIT FROM 1991 HONDA CR125 MODIFIED TO FIT. 4TH GEAR WILL HIT APROX 80 MPH. HAVE NOT TRIED 5TH AND 6TH GEAR. BIKE IS TOO LIGHT FOR THOSE HIGHER SPEEDS. DO NOT TRUST BRAKES FOR THOSE SPEEDS. NEED TO UPGRADE FRONT DRUMS TO DUAL PISTON DISC BRAKES.
12000 RPM. MAX RPM IS 13000RPM. this is for the race track on the road 11,000/11,500 spot on,
STOCK CYLINDERHEAD BORED TO FIRST OVER = IT175 CYLINDERHEAD MODIFIED ON A LATHE. at what angle was the squish re cut to and did you measure the squish also this lines up the edge to the cylinder bore,
CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. what size is the carb now,
REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; are both the same meaning,
wot = wide open throttle,
K&N AIR FILTER. have you oiled the filter
also you need the reed block porting and flowing and finishing off in 80 grit production hone marks this aids the mixing of the fuel and oil into the engine
taper port the front of the carb
open out reed stops
inlet port open 360 degree reed block stops and starts flow
exhaust port 22mm from top of cylinder liner and make the exhaust port wider as well
guide inlet flow towards boost port
line up transfer entrances on the barrel to crank cases
the ports need a 2mm chamfer at a 10 /12 degree angle
flat and polish piston crown and combustion chamber in cylinder head and the exhaust port
bigger carb
if not using a boost bottle then connect one
set squish to 1.00mm
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MY 1979 YAMAHA DT175 HAS 22 HORSEPOWER AT 12000 RPM. MAX RPM IS 13000RPM. DYNO TESTED USING A DYNOJET 2 WHEEL AUTOMOTIVE DYNO. USED ONLY ONE ROLLER INSTEAD OF BOTH. ORIGINAL HORSEPOWER WAS APPROX 14 HP AT THE WHEEL AT 7000 RPM. MODIFICATIONS ARE THE FOLLOWING:
IT175 CYLINDERHEAD MODIFIED ON A LATHE; SHAVED CYLINDERHEAD BUT MADE COMBUSTION CHAMBER WIDER. OCTANE USED 91 OCTANE. USED 1977 IT175 CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; MAIN AND IDLE JETS. K&N AIR FILTER. STOCK CYLINDERHEAD BORED TO FIRST OVER, PORTED TO SPECS OF 1977 IT175 PORTS SIZE. EXPANSION CHAMBER FROM 1991 HONDA CR125 MODIFIED TO FIT. MUFFLER PROCIRCUIT FROM 1991 HONDA CR125 MODIFIED TO FIT. 4TH GEAR WILL HIT APROX 80 MPH. HAVE NOT TRIED 5TH AND 6TH GEAR. BIKE IS TOO LIGHT FOR THOSE HIGHER SPEEDS. DO NOT TRUST BRAKES FOR THOSE SPEEDS. NEED TO UPGRADE FRONT DRUMS TO DUAL PISTON DISC BRAKES.
12000 RPM. MAX RPM IS 13000RPM. this is for the race track on the road 11,000/11,500 spot on,
STOCK CYLINDERHEAD BORED TO FIRST OVER = IT175 CYLINDERHEAD MODIFIED ON A LATHE. at what angle was the squish re cut to and did you measure the squish also this lines up the edge to the cylinder bore,
CARBURATOR MODIFIED; BORED OUT TO REDUCE VENTURIS. what size is the carb now,
REJETTED ON THE STREET FOR THROTTLE MAX AND FULL THROTTLE; are both the same meaning,
wot = wide open throttle,
K&N AIR FILTER. have you oiled the filter
also you need the reed block porting and flowing and finishing off in 80 grit production hone marks this aids the mixing of the fuel and oil into the engine
taper port the front of the carb
open out reed stops
inlet port open 360 degree reed block stops and starts flow
exhaust port 22mm from top of cylinder liner and make the exhaust port wider as well
guide inlet flow towards boost port
line up transfer entrances on the barrel to crank cases
the ports need a 2mm chamfer at a 10 /12 degree angle
flat and polish piston crown and combustion chamber in cylinder head and the exhaust port
bigger carb
if not using a boost bottle then connect one
set squish to 1.00mm
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hi everyone
my chrome air filter arrived today but i cant get enough clearance to fit it between the carb and the original airbox, is there any way i can remove the filter part of the airbox but leave the rest intact so i still have somewere to mount the battery to?
i think i may end up having to dremel the front of the airbox, but is there a way to remove it intact?
un bolt it from the frame, if you are using cone filter you might need to use a spacer tube and remember to check jetting so the engine does not run lean = holed pistons, what other mods as your dt got
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can any one tell me how to derestrict a 2005 xt 125 x, any help would be much appreciated
start at the air box is there a intake snorkel on the airbox if so remove it and make the hole that you see bigger and you could even drill holes in the top part above the air filter or even use a cone filter or a foam filter, also you could change the carb for a slightly bigger one and ream out the inlet manifold to the inlet manifold gasket and even the inlet port to the inlet manifold gasket, racing spark plug, performance exhaust, up the compression
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when you have re installed the crank, you need a feeler gauge to centre the fly wheel crank webs in the crank cases,
also you could try putting one half of the crank case in the oven and the main bearing in the freezer for the same time for 30 minutes, this applies to both crank cases
this is to expand the crank case so the main bearing goes in and the main bearing in the freezer contracts the main bearing and this is the same method for installing the crank in to the crank cases but then you put the crank case in the oven which already has the main bearing in then put the crank in the freezer
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in the photo below shows the rubber o ring this must be put
back on and a touch oil smeared on the rubber o ring
have loads of photos on a assembly of a vm round slide carb
on my forum
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Do Not De restrict the Bike!! I Did And It Went Bang, how would De restricting the engine make it go bang,
have you tried De restricting the air box and have you tried a foam air filter or a cone filter if you do this then you might need to up jet the carb to stop the engine running lean, you could try a different exhaust,
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you really dont want to know how i perceive him
yes i do want to know what was he like
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yeh make sure the old oilfeed pipe [from pump ] is blanked off properly . & when running in [rebored] make the twostoke mix alittle richer .[ plenty lube] say 30/1 or 25/1 ........
why would you need to run 30 to 1 or 25 to 1 when running in to much oil ratio and the motor will not run in right but this depends on the make of 2 stroke oil being used
run my motor in at 50 to 1
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Hi,
I bought a shed of a DT50 (yes, off ebay...............) and have done lots to it, but it won't run right.
It has had a rebore and piston, the 14mm carb was kaput so I got a brand new 16mm (yes, ebay again...............)
Starting is great, tickover fantastic, it revs up a treat, but, when ridden, it won't go onto the main jet, you can
bimble along on a part throttle all day long (hills are no good though) but open it up and she just dies, go back to
part throttle and she picks up again.
I've checked, and altered, the float height, it's running the correct 88 main jet, but just won't have it.
Do any of you guys know what may be the cause ?
Something else which may influence any suggestions, it's running pre-mix, the oil pump does not exist any
longer, perhaps I need a much bigger main jet now the petrol has oil in it ?
Hope someone out there can shed some light.
Thanks,
Roger.
but open it up and she just dies, go back to go back to
part throttle and she picks up again.
. might need a bigger main or might need a smaller main jet, a plug chop is need to sort this
you need to run it in first 500 to 750 miles no more than half throttle, also you need to do a plug chop, when running premix run at no less than 50 to 1
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need to grease up the linkages and swing arm spindle this means taking out the swing arm
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you could try using a ram air filter and a spacer tube, also a bigger carb,open out the reed stops, port and flow reed block,
port the barrel, line up transfer entrances to crank case mouth, set the squish to just under 1.0 mm, flat and polish piston crown/combustion chamber/ exhaust port, use a couple of base gaskets, racing spark plug and plug cap, ledar air corrector kit
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this called entrapment
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if the manifold sucks in air this will cause lean running and holed piston crowns
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fibre reed should be ok but these work with other mods done to the engine as well
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I Am in the process of restoring my bike it is the unrestricted type 10W not the 12A. It has a Micron Exhaust system and K & N type air filter fitted. Does anyone know what Jets I should fit on the carb So that I dont burn holes int the piston and over heat her as with the standard jets it is runnin too lean?
if you have a k and n filter you might need a spacer tube that goes on the back of the carb, a ram air filter might be better,
to find out what size main jet you need you have to do a plug chop to see the colour of the burn,
what size main jet are you running
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when I shift in the fifth gear at gaining full speed the bike loses power and the rpm keeps falling
is the gearing to high, like no spark is the ht coil dead
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just peg open the power valve
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or it could be the pilot jet to big
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yes it is the water pump oil seal what happens is when the seal goes the coolant goes into the gear box
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ihave a dt mx ,i have raised the top of the exaust port ...all is ok, a bit more mid boost..i have a gianeli exhaust ,trying to get a bit more pwer out of the engine,,,i have been told i could advance the timing
when you raised the exhaust port did you chamfer the edge this is to help the piston rings go over the port if you did not chamfer the edge of the port this could break the piston rings and wear them out faster,
if you want more power then try looking at bigger carb, open out the reed stops, change reeds, port and flow reed block
set the squish up to just under 1.0 mm, port the inlet port, match up transfer entrances to crank cases,
if you advance the timing too much this causes detonation holed pistons and makes the engine run slower, also when tuning you need to do a plug chop to see how the mixture is burning in the cylinder if you run lean then you get power fade then a nip up and or seize up and holed pistons,
you could try using a racing spark plug and plug cap
dt125 parts
in Yamaha Workshop
Posted
you could put a rd engine into your dt or you could put the complete top end of a rd on,
?have you tried e bay