2T Engine Change Tips

[Evo]

I'm going to be changing my engine over next weekend.

Mine is very noisy - piston slap, doesn't idle as it should so plan to have a go and changing it over myself. (Honda NSR)

Still rides as it should however, still gives me 105mph+(17k Mileage)

I'll be doing a straight engine for engine to save hassle.

Is there anything i should be wary of considering furthest i've gone on a bike is Airbox or Sprockets lol.

Hopefully i can get it done in 1 day.

I work with cars so many things i can relate back to.
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Bikes owned
1989 VFR 400 RR NC30

[alains]

except if it's a new engine you cannot swap them without checking top-end ,conrod play and crank bearings . so you must dismount barrel , clean carbon on valves,exhaust port,cylinder head and top piston . polish head squish & top piston as a mirror
when doing this , check barrel letter under the exhaust port as shown on this picture https://www.geneva-racing.com/~alains/lettre.jpg . it will be usefull is you change piston now or later as you will require a piston at barrel size (letter A to E , it's a E in my example)
also when starting first time think about 2 strokes oil getting in because it will a delay if the circuit is not clear of air
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the worst day fishing is better than the best day working

[Pete.]

It's not fair to say that you cannot do the swap without doing those things because you can, just that they are recommended.

Changing the engine itself is a simple process and should only take a few hours for even a complete novice. Make sure you unplug ALL the electrics , the engine earth and the throttle cables.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[alains]

sorry , i should have said : "it's highly recommanded to ....... "
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the worst day fishing is better than the best day working

[Blau Zedong]

Your going to swop a 2T engine that runs for a 2nd hand one of totally unknown pedigree?

Certainly a big gamble without even pulling the top end off for a quick look.

Be a shame to get it swopped then find out the replacement rattles like f**k.

It's always better to rebuild your existing engine rather than gamble on a 2nd hand one been any better where strokers are concerned.
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18:54:48 Rob Fzs: jews don't give away stuff for free

18:54:59 Rob Fzs: unless its their clothes/ hair/ golden teeth

[alains]

i am totaly with you
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the worst day fishing is better than the best day working

[Evo]

Nice tips.

Thing is, i'll have to run in a new piston/rings won't i ? and i don't want to have to run them in. Stick to 40MPH or whatever.
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Bikes owned
1989 VFR 400 RR NC30

[Pete.]

[alains]

depense on how look like your piston , may be rigns change might be enough . if piston change mind the letter under the barrel exhaust port because you must fit the correct size
look here how the letter is knocked (it's "E")
https://www.geneva-racing.com/~alains/lettre.jpg
and the joined doc shows you tyhe sizes
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the worst day fishing is better than the best day working

[Evo]

Down to last securing spindles of engine.

View picture here: https://www.nsr125.com/schem46.jpg

Number 15 seems stuck, can't get it out.

Does it thread into the frame ? i've removed a nut from one side and it will neither thread out(Though it does turn) or push out(Hammer Persuasion).
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Bikes owned
1989 VFR 400 RR NC30

[alains]

put the nut back without the washer , tighten the nut until the thread appear , then use a big nail punch and a havy hammer (if you've got a brass rod , this is ideal)
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the worst day fishing is better than the best day working