GT80GUY Posted October 15, 2014 Share Posted October 15, 2014 anybody know if I could fit a yamaha 100DX engine in my gt80? my engine is fu@%ed and a guy on my local classifieds said he'd sell me a DX for cheap but I don't want to spend the money and end up with a broken engine and a useless one. -.- Link to comment Share on other sites More sharing options...
Moderator Cynic Posted October 15, 2014 Moderator Share Posted October 15, 2014 Cheap engine swaps dont happen. Whatever is wrong with the gt it will be cheaper to fix than replace. You will need to work on the exhaust, air filter/carb. Engine mounts.. it goes on. Not least of all is the insurance will rocket. Link to comment Share on other sites More sharing options...
JimR Posted October 15, 2014 Share Posted October 15, 2014 Cheap engine swaps dont happen. Whatever is wrong with the gt it will be cheaper to fix than replace. You will need to work on the exhaust, air filter/carb. Engine mounts.. it goes on. Not least of all is the insurance will rocket. not 100% true certain yamaha products do have a modular approach (eg any V model (within reason), 2 stroke scooterette and not XV ) can interchange motors. However I can not remember coming across the GT80 or 100DX in the UK so as you say this may become costly as they may not be modular. if anyone is interested I could compile a list of 70's ~ 80's UK models that are/were modular and others that need mods but still fit ! Link to comment Share on other sites More sharing options...
slice Posted October 15, 2014 Share Posted October 15, 2014 Go for it Jim might make a fine post so folks can just look it up rather than ask the same question over and over. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 15, 2014 Moderator Share Posted October 15, 2014 not 100% true certain yamaha products do have a modular approach (eg any V model (within reason), 2 stroke scooterette and not XV ) can interchange motors. However I can not remember coming across the GT80 or 100DX in the UK so as you say this may become costly as they may not be modular. if anyone is interested I could compile a list of 70's ~ 80's UK models that are/were modular and others that need mods but still fit ! dont see much of you these days Jim but its always good to read your input Link to comment Share on other sites More sharing options...
GT80GUY Posted October 15, 2014 Author Share Posted October 15, 2014 Cheap engine swaps dont happen. Whatever is wrong with the gt it will be cheaper to fix than replace. You will need to work on the exhaust, air filter/carb. Engine mounts.. it goes on. Not least of all is the insurance will rocket. Link to comment Share on other sites More sharing options...
GT80GUY Posted October 15, 2014 Author Share Posted October 15, 2014 true true and true, except for the last part, she's too old to be on the street, she only reaches about 90km/h (60mph). but ok I'll get a new cylender and piston. I wonder if it'll be cheaper to bore out this cylender and get a new piston... MORE POWAAAA Link to comment Share on other sites More sharing options...
Moderator Cynic Posted October 16, 2014 Moderator Share Posted October 16, 2014 not 100% true certain yamaha products do have a modular approach (eg any V model (within reason), 2 stroke scooterette and not XV ) can interchange motors. However I can not remember coming across the GT80 or 100DX in the UK so as you say this may become costly as they may not be modular. if anyone is interested I could compile a list of 70's ~ 80's UK models that are/were modular and others that need mods but still fit ! Modular some maybe. How many people have been on this very site with the same or similar: "I got a cheap motor from a mate but". Then spending more in time and or money to fit/fix the replacement than repairing the original. Sounds like its only done the piston. Link to comment Share on other sites More sharing options...
dt502001 Posted October 16, 2014 Share Posted October 16, 2014 It will cost about 200 to bore it and throw a wiseco piston in it ,a new cylinder will be more than that alone. what is wrong with the motor or why are you saying it ducked? Link to comment Share on other sites More sharing options...
GT80GUY Posted October 19, 2014 Author Share Posted October 19, 2014 It will cost about 200 to bore it and throw a wiseco piston in it ,a new cylinder will be more than that alone. what is wrong with the motor or why are you saying it ducked? the cylender and piston are both scored, the exhaust literally spits oil out of it. Link to comment Share on other sites More sharing options...
dt502001 Posted October 19, 2014 Share Posted October 19, 2014 Well you needed to determin how deep the scratches are in the cylinder,to know if it is borable if the scratches are deeper than .030`` then its junk . Depending the condition of the rest of he bike you might just be better off to buy something else,a 1978 gt 80 is not a desirable bike and dumping alot of money into it ??? well thats up to you. You can sell off good parts of the bike how easy or hard that will be ? someone might be tring to have a set of bikes from 80cc to 250 and if you have a good set of original body work??? Godd luck with it. Link to comment Share on other sites More sharing options...
GT80GUY Posted October 22, 2014 Author Share Posted October 22, 2014 Well you needed to determin how deep the scratches are in the cylinder,to know if it is borable if the scratches are deeper than .030`` then its junk . Depending the condition of the rest of he bike you might just be better off to buy something else,a 1978 gt 80 is not a desirable bike and dumping alot of money into it ??? well thats up to you. You can sell off good parts of the bike how easy or hard that will be ? someone might be tring to have a set of bikes from 80cc to 250 and if you have a good set of original body work??? Godd luck with it. well I guess I'll have to take a look, everything's mint on it. fresh paint job, engine block is re painted. has original front fender (which apparently is rare) and looks beautiful. how do I post pics off my iPhone? I'd love to share it with you guys. Link to comment Share on other sites More sharing options...
Sacha Posted October 22, 2014 Share Posted October 22, 2014 I use tapatalk to post pics with my phone. a photobucket account is another route. Link to comment Share on other sites More sharing options...
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