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Yamaha xt350 17hp restriction

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Hi everyone, I am one of the unfornate people who has a 1992 Yamaha XT350 rated at 17hp.... Anyway I was wondering what yamaha did to restrict these (jetting???). Here is some background info: yamaha xt350 86-89 were rated at 27HP, 90-93 were rated at 17hp, and 94+ were 27hp again.. my motorcycle has a smog canister evaporative thing also (would removing this help performance at all?)... It is also listed on custombike:

http://www.custombike.org/bike_yam.htm

this is what is on there page:

YAMAHA XT350

1986 on, 350cc DOHC single

30hp, 90mph, 70mpg, 265lb

Neat thumper, potential as a road bike. Runs to 45k if well serviced; cams, valves go first – some in trouble at 20k. Later models restricted to 17hp but simple to derestrict. Many ended up well knackered from off-road excesses – frame quite easy to bend. Starting can be difficult. Rear linkage and exhaust go.

Thanks in advance. :cry:

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The intake manifold from the carb to the engine is restricted (Reduced inside diameter). Replace them with older models or grind it out.

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I too have one of those bikes - I took the carbs off last night and the intake between the carbs and the motor and there was no restrictions in there....Boycelaforest, what did you find out at the dealer.

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Asked the dealership, and they said there is a throttle stop on the carbs, I look at my carbs and there is a max throttle stop screw, but it is already allowing the throttle to pull to 100%. I dont know yet, going to talk to a guy that owns a motorcycle repair shop and have him take a look at it.

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what did you find out about the restriction I have a 94 xt, just bought it and seems to run, start, ride good any reviews or info is apreciated :cry:

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I have a 94 also, it is a great bike, the suspension is soft compared to my friends 97 honda xr250, but I can keep up with them on the trails and hill climbs. This bike has great torque! If you get a good set of knobbies there is nothing that it wont climb. I have just got used to mine and feel comfortable with throwing it around, it runs great and seems pretty much bulletproof, fun bikes!

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Maybe I am not reading this right, but it seems nobody came up with a way to derestrict these bikes... Help! CJ

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I'd like to know too. I just started commuting with my 1992, and the freeway parts of my mixed commute are a little tough. Can't even hit 60mph without a tailwind. Fairly sure it's not a malfunction. The bike runs great. Just runs out of steam at highway speed limits.

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This is interesting. I have a 1986 Yamaha XT350 and I have never once had a problem getting my bike to 60mph on the highway. Infact I can run her at 90mph right on 8500rpms. I also have the 18 tooth sprocket in the front. I have removed the baffle also. The bike runs pretty strong. Find those restricters and get rid of em cause when you open this bike up shes a low end torque monster. Atleast the newer ones are a little less ugly. I can't stand the red and white.

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I'd like to know too. I just started commuting with my 1992, and the freeway parts of my mixed commute are a little tough. Can't even hit 60mph without a tailwind. Fairly sure it's not a malfunction. The bike runs great. Just runs out of steam at highway speed limits.

I've had my dad's all-stock 92 XT350 at about 80 before with plenty left in it. I didn't go any faster because I wasn't supposed to be on the road and because the wind was beating me to death. I recommend taking te baffle out of the muffler. One screw and it comes out. I did have the baffle in when I hit 80. Also I'm not sure about the 90-93s only having 17 horsepower. In a drag race my dad on his XT350 (probably almost 500 pounds combined) can beat me on my KX100 (about 300 pounds). My KX probably has about 20-23 horsepower. It would take a considerable amount of more horsepower for my dad to beat me. And I'm actually a little bit better of a rider, so it wasn't me that was the problem.

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