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Discussion Starter · #1 ·
Just did a little bit of an overhaul on my 04 SM450 because last time changed the oil i found 3 gear teeth and a circular bushing in the bottom of the crankcase. Found out it was teeth off 6th gear on the mainshaft and one of the bushings that goes between your shift forks and shift drum. Anyways, replaced what need to be replaced and put the motor back together. I also replaced a cracked intake manifold and a missing airbox clamp. Ok so my question is...:headscrat

Since the rebuild my throttle "wackability" has been lost. Would you suggest the carb needs tuning after replacing the intake manifold and clamp? I havent had the bike long and found the mixture screw to be 6 turns out... Maybe to compensate for leaking intake seals? I compaired my jetting to some other people and definitly think i need a jet kit but the bike ran fairly well be for the tear down. FMF Pipe, Uni foam filter, sealevel, Main 175, Pilot 35. Im guessing this is stock?

OR could my timing be off my a tooth or so? What happens when your timing is off a tooth? bike fires up no problem, revs fine as long as you dont wack it. If you wack (rev the engine fast in neutral) the throttle hesitates for just a second then either the revs take off or it dies. On test rides down the road it seems ok, surges a little while cruising around 5k. Ive messed with the carb and mixture screw (turned it in from 6 to 2 turns out) and have got it better but i want it to purrr.

Any suggestions would be great.
 

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throtle wack

i believe there is a blog on carb settings on here somewhere. You will want to check your leak jet while you do the rest of this. JD kits work, but the finish on the needles leaves a bit to be desired. the stock mfg needles are alum but they are ground super accurate and super smooth.
 

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Discussion Starter · #3 ·
Ok thanks for the info. Im going to go to my local yamaha dealer tomorrow and see if they have some mikuni jets. What about the jet needle/slide needle? I know with most dyno jet kits you get a new needle, should i be ok with the stock needle and these bigger jets?

Ill have to do a little research on the leak jet, not exactly sure what were talking about, is that another word for the air bleeds?

Can someone verify for me that cam timing (off a tooth) would or would not create the carb hesitation. Will the bike be street worthy at all if the timing is off by a tooth?
 

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cam timing being off would make starting extremely hard. Sounds like either your accelerator pump needs adjustment, or the pilot jet is not the correct size. 1st off, did you clean the carb really good when it was apart. Possible that some of the old fule varnished on the pilot jet and is causing this issue. A cracked intake manifold would create an erratic idle if the air leak was significant. I would clean the carb really good first, then post back up what the result is. Also, a rule of thumb is to not have the fuel screw more than 4 turns out or you risk losing it if it falls out....also, if it needs to be turned that far out, you should bump to the next sized pilot jet.


-Craig
 

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Discussion Starter · #5 ·
I did a quick once through on the carb while the bike was apart, jets were clean no varnish in the bowl. I was also thinking of investigating the accelerator pump. Is their an adjustment procedure?

Thanks for the info.
 

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I did a quick once through on the carb while the bike was apart, jets were clean no varnish in the bowl. I was also thinking of investigating the accelerator pump. Is their an adjustment procedure?

Thanks for the info.
yes, there is adjustment for the AP. Search Thumpertalk for "Accellerator Pump adjustment". Also, even a small amount of varnish on the pilot jet will close the gap enough to cause issues. I would take the carb apart and clean it good to rule out dirty carb jets.
 

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Discussion Starter · #7 ·
Ok, did a good carb clean today as well as change my jetting up a bit. Went from a 35 pilot to a 45, and changed my main from a 175 to a 190. Took her for a short spin and the bike ran alot better. It was dark by the time i got done so didnt get to check the plug. Ill check it out tomorrow and see if i need to make any more adjustments. I also bought a couple extra jets, a 185 and a 45, from a local shop just in case.

I would like to do the leakjet mod, did a little research but all the examples ive found are with a different carb. Looked at what i believe is my carbs leakjet but it is way to small to try and remove, doesnt look like a JET more like a pressed in brass insert or something.

The bike is running way better now though, thanks for all your input!
:thumbup:
 

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Only make one change at a time. which carb do you have? FCR 39? The low end bog that you spoke of would have nothing to do with the main jet in the carb......pilot jet handles from idle to 1/3 throttle, main takes care of 1/3 throttle to WFO. Were you having issues with the top end too?
 

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leak jet

for smog reasons some bikes came with a blank plug, instead of a drilled leak jet. I would replace it with a proper jet. 65 or 70 should be pretty close. perhaps someone else can chime in on what they are using.
 

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Discussion Starter · #10 ·
Sorry for the delayed reply,

Craigs, I dont know exactly which carb i have, im slowly figuring out that this bike is a bit of a mutt. I wasnt having any problems with my top end at the time of rebuild, just horrible noise and vibs while crusing in 5th and 6th gear, then found sheered teeth in bottom of my engine so i tore her apart to fix the trans. Checked the valves on the way out, within spec.

Reason i say she is a bit of a mutt is because i realized a few of the parts on my bike are not stock. When taking the top end off first noticed the piston was not stock. Only one ring and a scraper, didnt measure but i should have. And, when looking for the ap adjustment and mod threads noticed my carb doesnt look like the one in the picture. Ill attach a picture of the carb, maybe someone can tell me if it is stock or not. Only thing i can see that looks different from any of the carbs ive worked on in the past is it has 8 bearings that the throttle slide rolls on. Maybe that will tell you something, maybe they all have that...

Reason i changed the main jet was just in comparison to others on the site. seemed like the bike was struggling after the rebuild, even cruising at higher rpms. After the jets its is alot better, only this is she doesnt like cruising at a steady speed, around 5000 rpm either wants to go or decel. is does cruise but you have to really keep a steady throttle hand, the bike was like this alittle before the rebuild so thats why i havnt paid it much attention but do your huskys have the same manners?

Just want to say you guys are the best, thanks for all the advice and pointers. :clap:

Pic of carb...
 

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Maybe one of the 04 owners will chime in, but I thought all the carbed Husq"s had either the FRC 39 or 41 flat slide made by Keihin......I am not familiar with the Mikuni in the pic.....Sorry bud, I can give no more advice:anim_peep:
 

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Make sure your pilot jet is clean and try 1 3/4 turns out with the mixture screw. It looks like stock is size 30? No idea either about the Mikuni.



Type (450)...“Mikuni” TMR 41 with acceleration
pump and T.P.S. (Throttle Position Sensor)
Venturi diameter (TE 250 ......................1.42 in.
Venturi diameter (TC 250-SM 400 R)....1.50 in.
Venturi diameter (450)...........................1.61 in.
High speed jet (TE 250)..............................150
High speed jet (TC 250) .............................155
High speed jet (SM 400 R) .........................165
High speed jet (450) ...................................175
Low speed jet (250) .................................. 22,5
Low speed jet (SM 400R) .............................25
Low speed jet (TE, SMR 450).......................30
Low speed jet (TC 450) .............................32,5
Throttle piston ..............................................1.0
Metering pin ..................................................52
Metering pin groove
(TE 250, TE-TC-SM 450 R).........................3rd
Metering pin groove
(TC 250 - SM 400 R)......................................4th
Main nozzle ....................................................P4
Idle mixture adjusting screw (250-400) (turns)..2
Idle mixture adjusting screw (450) (turns) . 1+3/4
Acceleration pump jet (TE 250, TE 450, TC
450, SMR 450-SMR 400)..............................30
Acceleration pump jet (TC 250)....................35
 

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Restucky is right that is the stock Mikuni TMR 41 that all the 04's came with. If you are looking for some more jetting info there is a few different threads about the Mikuni over on thumpertalk. From what I have read it looks like you are at least barking up the right tree. I still haven't gotten around to playing around with the jetting on mine to see if I could do better. Definitely let us know what you end up settling with.
 

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Discussion Starter · #14 ·
Restukey, Thanks for the info on the jets, im going to try the mixture screw at 1 3/4 tomorrow, and absolut thanks for the confermation on the carb, glad to know it is the stock carb.

Took her out the other night and had a blast, I feel like she could still use a few tweeks but im not going to let it stop me from riding.

Thanks for the help, ill let you know how it goes. :thumbup:
 

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motorider, i had the cam timing one tooth off and these were the symptoms: difficult starting, coming to a stop after riding the bike hard the idle would drop down real low and frequently die although the bike would start right up, low on power/fuel economy but there wasn't a bloggin hesitation like you're explaining.
 

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Discussion Starter · #16 ·
Thanks for the input cb, just what i wanted to hear. Wanted some reassurance that i didnt have the timing off. my bike starts within 1 second of pressing the button, and stays running till i turn it off. I just wanted to rule that out seeing as i just did a complete tear down.

Thanks
 
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