trailshee23 Posted March 2, 2012 Author Report Share Posted March 2, 2012 i rode my friends 421 and it is way to much for our trails we even did some timed runs and mines a little faster so with that being said lets hear about the 392 servals Quote Link to comment Share on other sites More sharing options...
rjdgriff Posted March 2, 2012 Report Share Posted March 2, 2012 With ur friends sprocket sizes it's no wonder he can't trail worth a shit lol Quote Link to comment Share on other sites More sharing options...
Titan up Posted March 3, 2012 Report Share Posted March 3, 2012 Take the 421 and subtract about 5-7 hp and about 3ft lbs and there's your 392...The smaller motor would have a slightly peakier (if that's a word) power band which may make the situation worse. Like mentioned earlier, it's all about set up and rider ability..The tighter and more technical the terrain, the more this plays a factor. Quote Link to comment Share on other sites More sharing options...
trailshee23 Posted March 3, 2012 Author Report Share Posted March 3, 2012 well my cylinders are junk now and i dont want to buy someones junk cylinders off ebay thats when i found the servals but i cant find any info on a 392 my plan is to make a 392 long rod im not sure about carbs or pipes yet im thinking cpi pipes with 28 or 30mm carbs but any info you have i can use let me know Quote Link to comment Share on other sites More sharing options...
Titan up Posted March 3, 2012 Report Share Posted March 3, 2012 28mm would be good or even your stock one's...For trail riding I would run Pro Circuit pipes. They make the most low end power of any pipe on the market If I were in your shoes I would be on the phone with FAST or M&M atv..Those 2 guys have built enough servals, to answer any questions you have. Check the sponsor forum for contact info. Quote Link to comment Share on other sites More sharing options...
lms1977 Posted March 3, 2012 Report Share Posted March 3, 2012 you will have to get your crank welded and at this point but new bearings on I would think, that being said I would consider the 421 serval again since you have to split the cases. with the bigger serval you are able to ride them in a higher gear in the trail and with mine it kinda acts like a 4 stroke where you dont need to shift very much ( I have the 10mil serval) I think the 392 serval would be great for someone who just bought a new welded crank and now wants to do the topend Quote Link to comment Share on other sites More sharing options...
trailshee23 Posted March 3, 2012 Author Report Share Posted March 3, 2012 (edited) my crank went out thats why my cylinders are junk now i have to rebuild top and bottom i read that a long rod crank last a little longer so thats what im going with Edited March 3, 2012 by trailshee23 Quote Link to comment Share on other sites More sharing options...
dcalsv02 Posted March 3, 2012 Report Share Posted March 3, 2012 Grab a set of Paul turner mids. Those pipes by far have the most bottom end than other pipes. Quote Link to comment Share on other sites More sharing options...
trailshee23 Posted March 4, 2012 Author Report Share Posted March 4, 2012 i have a set of pc pipes now but im not sure if they will work or not with a 392 serval Quote Link to comment Share on other sites More sharing options...
gotta_goatsfast Posted March 4, 2012 Report Share Posted March 4, 2012 I ride a 421 serval and it absolutely pulls away from all the 4 strokes and bolt on banshees that I ride with (anything from black diamond trails to hair scrambles). For you, I would suggest you save some cash. Pick up a 4 mil crank and some stock bore/port cylinders. Send them out for a woods or MX style port. A stroked "low-mid" port motor will be your best bet in tight trails. Since you keep stressing tight trails and woods, your first concern should be the suspension/tires/brakes. This will ultimately make you faster than any motor will in these conditions. Quote Link to comment Share on other sites More sharing options...
georgie Posted March 4, 2012 Report Share Posted March 4, 2012 your friend needs to learn to ride....as there shouldn't be any reason that a stock stroke ported bike is being a 421 serval setup. something is wrong.... we don't know the complete set up of both bike's, you can't take a 4 mil. set up for trailing and go drag race a stock stroke bike set up for drags. Don't under estimate stock stroke bike's set up for drags, they rev out faster Quote Link to comment Share on other sites More sharing options...
trailshee23 Posted March 4, 2012 Author Report Share Posted March 4, 2012 i have elka shocks yfz brakes and itp hd tires so im good with all that and yes my brothers shee revs like a sob im not sur what he did to it i posted the last known mods but i do know it was the same as mine but a smaller bore who knows now he wont tell he hasnt had the bottom end apart tho just the top Quote Link to comment Share on other sites More sharing options...
Titan up Posted March 4, 2012 Report Share Posted March 4, 2012 i have a set of pc pipes now but im not sure if they will work or not with a 392 serval Quote Link to comment Share on other sites More sharing options...
andrew3160 Posted March 4, 2012 Report Share Posted March 4, 2012 There is another thread on here that shows dyno numbers with Pro Circuits, CPI's, and one other pipe. The Pro Circuits seemed to do great on a 421 Serval. I ran pro circuits on my ported 4 mill stock cyl and that thing ripped with a very usable power band. You might want to consider trying the Pro Circuits first. 28mm Carbs would work real well on a 392 and help preserve some low end. Quote Link to comment Share on other sites More sharing options...
trailshee23 Posted March 4, 2012 Author Report Share Posted March 4, 2012 would i need to upgrade my tranny or would it be ok to rin the stock one Quote Link to comment Share on other sites More sharing options...
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