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DRZ400SM sprocket setup

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hi guys, i have some questions, ive been doing some research on this topic and there is a million and a half of these "what sprocket set i should use" topics, but none of them really answer the entire question, or that i have found anyways.

i have a 2007 suzuki DRZ400SM and i have gone trough chains or sprockets about every year, and through out the shot 6 or so moths that i get to ride i am constantly setting the chain tension. The last set that i put on was not the most expensive but also not the cheapest set up and that only lasted about a season. 

im thinking about going with a 16/39 set up but i dont know what thats going to do to my low end, well i shouldn't say i dont know what its going to do to it i know its gonna bog it down alot, i just dont know how the bike is going to handle it and even if a stock engine with after market exhaust and 3x3 air mod dine incorrectly (i didnt do the 3x3 mod it was done when i purchased the bike) and if i should re jet the carb. or what brand i should go with that well last more than one season.

if i do end up going with the 16/39 set up what link chain would i have to go with?  

ive been looking every where for this set up in a compleate set but all i can find is for other bikes not the drz and im not sure if the bolt pattern and spline shaft pattern are going to match the DRZ's

ANY help would be appreciated!!!!!!!!  

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you shouldnt need to adjust the chain all the time even with a cheapo chain .. i run a non-oring standard chain and its got over 3k miles on it and ive only adjusted it once .. just be sure to use a good lube and DONT chase it with the adjuster - if you run the chain too tight on the drz it will just stretch it and stretch it every time you adjust it tighter ..

16/41 is as high as the drz can pull well unless all you are doing is long highway rides, acceleration is not good with 16/39 .. you could go 15/38 also which is about the same ratio as 16/41  ... i use a 16/41 and it will take slight mods to the chain case guard and front of the chain slider to fit a 16 .. a sunstar 32316 is the front i use, JT brand 41 (JTR808.41) is the rear i use, on the chain, buy it long and fit it and break it on the bike after you have everything mounted, thats the correct way to do it .. whichever link puts the adjustment closest to the middle of the range is the best place to break .. the chain adjustment should be alittle more than 3 fingers of slack in the middle top of the swingarm, double check by leaning over the bike from the right side and putting all your weight on it, reach down and be sure there is still alittle slack in the chain, it should 'not' be anywhere near tight with your weight on it ..

Edited by cowpie
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I might have more mods than you, but I run 16/39 on the street and it's alright. Currently on 15/39. 

Why are you constantly replacing chain and sprockets? Are you running aluminum sprockets? If so, just go steel. As for brands, get a DID 520 x ring chain, and JT sprockets and forget about it. Neither are expensive on ebay. Just keep it lubed and set the slack right the first time. The chains come pre stretched so you shouldn't have to keep adjusting it.

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Thanks for the all the advice. what do you have for mods on ur bike HansLanda?

i dont know y its going tough sprockets, i have set the chain tension 2 different ways to see if it helped with getting slack over a few weeks. the first way i did it is the recommended way. the way cowpie mention to leave about 2-3 finger slack in the middle of the swing arm. with no luck. then i read in a couple of different forums that if you put the closed end of a 10mm wrench on the back sprocket you and up with the tension set to about the equivalent of the 2-3 finger slack. once again with no luck.

i have also noticed a lot of metal shavings around the swing arm even if i lube the chain. i replaced my counter shaft seal last year and everything looked good behind the sprocket and the counter shaft felt good.

ill look in to the did chain and sprockets. thanks again for all your input       

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I agree with HansLanda.....i run the standard 15 front tooth sprocket and have had a custom built 37 tooth sprocket for the rear.I hardly ever use it on the highway and mods are just 3x3,jd jet kit and k&n air filter.Engine not labouring as much due to the sprocket setup-still runs like a raped ape.I am anal when it comes to maintenance however and i lube and adjust the chain every month-and that is without taking it off-road.Quality 0-ring chain-Did and JT Sprockets as HansLanda says-is the way to go.Had mine on now for three years and the sprockets and chains look still good as new.Thats doing 1800km per month.The standard length chain should be fine as they are usually very long,just get a couple of extra masterlinks.Must admit though that doing the 3x3 mod,air filter and jet kit made quite a big difference on performance.

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alright ill i think im going to find a DID chain, and JT 38 rear sprocket. what kind of lube do u guys use on your chain? and if im replacing the chain and rear sprocket i should replace the counter shaft sprocket as well correct?  

ive played a lot with 2 stroke carbs but have not played with 4 stroke carbs at all, are they relatively the same as far as jetting ?  

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2 hours ago, Eddy5150 said:

Thanks for the all the advice. what do you have for mods on ur bike HansLanda?

Athena 434, FCR39 slant, FMF Powercore 4 + Powerbomb, K&N/Twin Air, 3x3, SM & S wheels. Soon adding Hotcams.

1 hour ago, Eddy5150 said:

what kind of lube do u guys use on your chain? and if im replacing the chain and rear sprocket i should replace the counter shaft sprocket as well correct?  

ive played a lot with 2 stroke carbs but have not played with 4 stroke carbs at all, are they relatively the same as far as jetting ?  

I use Maxima chain wax. I think there are better lubes out there though. My friend swears by Motul, but I haven't used it. Pretty expensive.

https://www.amazon.com/dp/B0012TZ1RU

https://www.amazon.com/dp/B008N69C7U

Some people are anal and anytime one of the three wears out, they replace them all - both sprockets and chain. It makes sense in a way because the chain and sprockets wear down together. If you put a brand new sprocket on a worn out chain, the sprocket will wear faster, and vice versa. I just replace a single part at a time. Steel sprockets and chains last so long anyway I don't mind "spending more in the long run," if you know what I mean.

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Thumpers are harder on chains, has to do with the single power pulse.  A worn sprocket will kill a new chain.  Run more chain slack and use steel sprockets.  I run JT or Sunstar sprockets and change sprockets and chain.  Expensive sprockets wear out just as fast.  Industrial supply houses sell 520 chains in 50' & 100' lengths, expensive purchase but cheaper in the long run.  15/41 to 15/39 are the usual SM sprocket sets.  16/39 is better suited for big bore / cam / carb modded engines.  Will work on a stock motor but accel at frwy speeds is less than I'd like (unless you weigh <140lbs).

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alright sounds good. im just gonna stick with the 15/39 im going to keep the same counter shaft sprocket as i have in it now its not worn. im gonna go with 

JT Sprockets JTR808.39 39T Steel Rear Sprocket. 

DID 520VX2GB-110 Gold X-Ring Chain 

i do want to do a jet kit before i take it out for the season any advice with that?

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alright ill i think im going to find a DID chain, and JT 38 rear sprocket. what kind of lube do u guys use on your chain? and if im replacing the chain and rear sprocket i should replace the counter shaft sprocket as well correct?  
ive played a lot with 2 stroke carbs but have not played with 4 stroke carbs at all, are they relatively the same as far as jetting ?  

A quick note on chain lube, I always lube my chain when I get home from a ride, that way any moisture on it gets displaced and won't corrode it while its parked.

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alright i dont wanna sound like a super nube but ive never played with small 4 stroke carbs so im kinda on the nervous side to f*** with it. any words of encouragement and how  much of a pain in the as* is it to tune it post new jets.

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