g9 help

[grizz454]

hey all. been a while since ive been on here and I need some help. ive got a 94 g9 that's having some problems. first off, I have changed motors. the one that was in there smoked really bad and was way down on compression. the used motor I put in runs really quite and no smoke at all. the problem is it has no power and seems like it only runs half throttle. I know it is openening up all the way. ride for a while and all of the sudden it will take off and run as it should until you park it for a while and then it starts all over. read to loosen the exhaust bolts to see if it runs better so I tried it.. its blows so many sparks out of it and the end where it bolts will get red hot in seconds with it loose. throttle don't respond any different when its loose. I didn't try riding with the exhaust bolts loose cause im afraid sparks will hit the gas tank. it sparks so bad it looks like someone is grinding in there with a grinder. any thoughts?

[jeff70]

Have you done a tune up? and check the valve adjustment

[CAMPERCART2013]

Grizz not sure what you've checked yet but sounds like what I went through last year get or borrow a spark tester think there around $10 at orielly's ? Check the spark when it is running poorly then when it runs great it will be ALOT brighter.dim and weak mostlyeven spar attic then all the sudden really bright.if you read my posts you will see all I went through. I started with air and fuel then ignition.at the end of the day it was the igniter/Cdi everyone will give it a different name but it's the little black box screwed to the gas tankthank you again to everyone that helped me with this one smallblock Boke Mac Don at plow mans and g1-g9 for hooking me up with a gently used one oh and don't forget to check the grounds on everything or Mac will remind us lol great bunch of people on here dont give up on it i almost did you'll get it figured out

[grizz454]

I have. new spark plug and checked the valves. this motor had a ngk plug... something 8 don't remember right off what the letters were but I have read it should be a 4 or even a 2. would that have anything to do with anything. told the guy at the parts place I thought I needed a 4 instead of the 8.. he said that was thread design?

[grizz454]

camper, I have another ignitor from a 91 g9 I was going to try. my 94 has 6 pin plug and the 91 has more than that. it looks different

[CAMPERCART2013]

grizz I also have a 1994 G9 and according to the yamaha manual it calls for a BR4ES with .028-.031 in gap you can download and print the manual alot of great info and people on here i am unsure what to say about the different ignitors? i believe mine has 5 wires i'm sure someone will chime in and help on this one eventually did you try the spark tester yet?

[cgtech]

G9 ignitor is different from all the others. I think the different models all had different ignitors. In the "engine swap" thread/stickie, the ignition system differences are covered in more detail. Ngk BR4ES is correct plug for all G2-G14 models as far as i know.

[grizz454]

the replacement motor is a 91 g9 I was told. the pulsar coil is the one that goes to spark plug right? I will change them to see if its any different in running. there were only 2 plugs to plug into my wire harness and they matched my plugins

[cgtech]

Pulser coil is the crank trigger, not the one that actually makes the spark (hooked to spark plug). Both of your G9 motors should be compatible with your current electrical system.

[grizz454]

thanks for all your help. I will see about getting a ignitor to try, just hate to spend that much on a part if that's not it. still confused on why so many sparks when the muffler is loose. wouldn't think its normal but I don't know.