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Discussion Starter · #1 ·
i already have a full yoshi system,k&n with the airbox lid off and a jet kit how much power will going to a 686 11.1 piston and cam produce? about how much does it cost to do this
 

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Around 50-52hp

Parts:
Piston - 125-250
Cam - 140-250
Valve springs (if not a drop in cam) - 150
Gaskets/RTV - 20

Plus labor costs and machining (bore, hone, valves)
 

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Discussion Starter · #3 ·
would this be a pretty reliable setup? good for the dunes? about how much hp am i at with the k&n and full yoshi
 

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cams76 said:
would this be a pretty reliable setup? good for the dunes? about how much hp am i at with the k&n and full yoshi
Quite reliable, but I wouldn't suggest going all the way to 102mm (686) right away. You can probably just hone and put in a 100mm piston, or if you've got a lot of hours on it you may need to go up to a 100.5mm. Be sure to check your cylinder for clearances before ordering the piston, unles you plan to bore anyway.

With the smaller piston you'll get most of the hp and still have room to re-hone/re-ring or bore again if you need to. 102mm is as large as the oem sleeve will go, and if you grenade a 102mm you'll be looking at a new sleeve instead of just a bore.

You're probably around 45hp or so with the current pipe/filter setup. I have seen/heard of unported 686's in the mid 50's.
 

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Discussion Starter · #5 ·
its an 05 and doesnt have many hours on it so maybe i could just put the same bore but just a higher compression piston and a cam also will this be a noticeable enough power gain to do all this
 

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Yes, there's certainly a noticeable "seat of the pants" increase in power.
 

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how much does a sleeve cost? and i already purchased my stage 3 or stroker cam. and i was planning on the 686 but am now im curious is there a big power diffence between stage 2 and stage 3 cam??
 

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Mia Ruff-Ryder said:
how much does a sleeve cost? and i already purchased my stage 3 or stroker cam. and i was planning on the 686 but am now im curious is there a big power diffence between stage 2 and stage 3 cam??
The stage 3 is not really designed for a trail motor, and judging from it's similarity to another cam it's best paired with an aggressive port job and/or a large displacement. I'd be afraid that without the porting and fuel to feed it you'll be worse off. If you're building a mild 686 I'd suggest the stg 2 over the stg 3.

A sleeve is around 150 bucks plus any labor charges to put it in.
 

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I'm in the same boat, you guys have helped me decide on all my mods and this is whats next. I ride trails and being in the part of texas where I'm at theres alot of 4x4 riding areas not so much for us. With my mods listed below I put down just over 52rwhp, but I'm gunning for 60+rwhp but VERY reliable. Since then I've also put a new fan and fluidyne heat exchanger(got for free as a test unit due to the one on my lightning clogging and almost trashing a 20k motor).


Or should I sell it(under 30hrrs on it) and pick up a 700SE and mod it?
 

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Discussion Starter · #10 ·
if i go with the stock bore but do 11.1 compression and a cam what jetting will i need i just jetted it for the pipe and airfilter
 

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cams76 said:
if i go with the stock bore but do 11.1 compression and a cam what jetting will i need i just jetted it for the pipe and airfilter
Let me know how this works out when you do it please, I've already broke the 50rwhp mark and am looking at this as my next mod.
 
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