Oregon dunner Posted February 13, 2012 Report Share Posted February 13, 2012 I was wondering if there was a topic about 4mill 421 cub jetting? Thanks Quote Link to comment Share on other sites More sharing options...
Boston Posted February 13, 2012 Report Share Posted February 13, 2012 give all the info about your motor that you know? elevation, pipes, carbs, timing, reeds, pretty much everything you know about it and people can help with what jets youll need Quote Link to comment Share on other sites More sharing options...
BUILDER Posted February 13, 2012 Report Share Posted February 13, 2012 Kind of need to know what carbs you are running to be able to tell you what jets you need. I have 34pj's on my 421 cub and I run a 150 main and a 55 pilot with a ceg needle Quote Link to comment Share on other sites More sharing options...
Oregon dunner Posted February 24, 2012 Author Report Share Posted February 24, 2012 I have 35 pwk carbs with a 52 pilot and 155 mains and no clue on what needle i have. My current mods are 19cc domes, 4 mill crank and of course cub cylinders with a aggressive dune/drag port and port match case by HJR. I am running +4 timing and cpi inframe pipes and riding at sea level. Quote Link to comment Share on other sites More sharing options...
Titan up Posted February 24, 2012 Report Share Posted February 24, 2012 I have 35 pwk carbs with a 52 pilot and 155 mains and no clue on what needle i have. My current mods are 19cc domes, 4 mill crank and of course cub cylinders with a aggressive dune/drag port and port match case by HJR. I am running +4 timing and cpi inframe pipes and riding at sea level. That sounds close, maybe a little on the leaner side..How does it run? I had the same setup except for shearers and was anywhere from 152-158 main, between 300-1200ft above sea level..That was with an EEK needle which is on the richer side for needles...I ran the cub both out of the box and later on with HJR drag porting and to my surprise after the drag porting, it still wanted the same size main, if anything it wanted less. Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted February 24, 2012 Report Share Posted February 24, 2012 That sounds close, maybe a little on the leaner side..How does it run? I had the same setup except for shearers and was anywhere from 152-158 main, between 300-1200ft above sea level..That was with an EEK needle which is on the richer side for needles...I ran the cub both out of the box and later on with HJR drag porting and to my surprise after the drag porting, it still wanted the same size main, if anything it wanted less. What size pilot did you run with that setup and what elevation? Quote Link to comment Share on other sites More sharing options...
SonOfSand Posted February 24, 2012 Report Share Posted February 24, 2012 That sounds close, maybe a little on the leaner side..How does it run? I had the same setup except for shearers and was anywhere from 152-158 main, between 300-1200ft above sea level..That was with an EEK needle which is on the richer side for needles...I ran the cub both out of the box and later on with HJR drag porting and to my surprise after the drag porting, it still wanted the same size main, if anything it wanted less. Hey Titan, when you went from the cast to the ported cub, was it a noticeable increase in power, and where was the increase? Worth the $300? Quote Link to comment Share on other sites More sharing options...
Titan up Posted February 25, 2012 Report Share Posted February 25, 2012 What size pilot did you run with that setup and what elevation? 48 pilot and that was for about 300ft above...I bought the carbs through Cascade and I told them I'll be riding Glamis, so they set them up for with 48p, EEK 4th clip down and 158m...After a couple trips out, I ended up dropping the needle down a clip to 3rd because it was a little rich in the mid..Other then that it was perfect for the 3 yrs I rode it, never melted down a topend. Hey Titan, when you went from the cast to the ported cub, was it a noticeable increase in power, and where was the increase? Worth the $300? I don't have any track times or dyno numbers, so just based off of seat of the pants, it felt like it had a little more over rev, but it definetly made the bottom end worse..The bike will not leave in 2nd gear period. Plenty of compression, 14-44 gearing, +4 swinger, 21x12x8 8 paddle extremes, 200lb rider and 2ng gear starts are not happening..Rev it to the moon, drop the clutch and BAAAAAWWGG.. The 21's went on at the same time of the porting, so not sure how the original 20x10 8 paddle haulers would have fared, in which I could leave in 2nd and sometimes 3rd, with 14-41....Me being more of a duner then a dragger, I don't want to be slipping the clutch and riding constantly at 8000+ rpm on a dune journey. Overall it might of had a smidge more power way up top.. It ripped before and it ripped after, so it's hard to say. If had to do it over again I would have sold the cylinders instead of the bike and replaced them with a Serval setup... Quote Link to comment Share on other sites More sharing options...
SonOfSand Posted February 25, 2012 Report Share Posted February 25, 2012 Thanks for the feed back Titan. I just installed a cub, could have gone with the serval but changed my mind at the last minute. Hope I don't regret it. Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted February 25, 2012 Report Share Posted February 25, 2012 What domes, compression and type fuel were you running titan and what will you be running sonofsand? Im building a 421 cub too, and it'll be on pump gas. Quote Link to comment Share on other sites More sharing options...
SonOfSand Posted February 25, 2012 Report Share Posted February 25, 2012 What domes, compression and type fuel were you running titan and what will you be running sonofsand? Im building a 421 cub too, and it'll be on pump gas. I am running 19cc domes at 5000 feet. running straight AV gas LL100. +7 timing. I hope it is a big improvement over my HJR 4 mil stock cylinder drag port. Quote Link to comment Share on other sites More sharing options...
Titan up Posted February 26, 2012 Report Share Posted February 26, 2012 What domes, compression and type fuel were you running titan and what will you be running sonofsand? Im building a 421 cub too, and it'll be on pump gas. For the first 2 yrs I ran 21cc domes, straight VP c-12 (108 mon)...After the porting, I ran 19cc domes to help with the bottom end with timing anywhere between 4-7*. The 19's did help some. My compression tester reads low because it doesn't thread in as far as a spark plug, so I just used it as a gauge to periodicaly checked compression levels. Quote Link to comment Share on other sites More sharing options...
SonOfSand Posted February 26, 2012 Report Share Posted February 26, 2012 For the first 2 yrs I ran 21cc domes, straight VP c-12 (108 mon)...After the porting, I ran 19cc domes to help with the bottom end with timing anywhere between 4-7*. The 19's did help some. My compression tester reads low because it doesn't thread in as far as a spark plug, so I just used it as a gauge to periodicaly checked compression levels. Do you prefer your LTR to the banshee you sold? Quote Link to comment Share on other sites More sharing options...
Titan up Posted February 28, 2012 Report Share Posted February 28, 2012 (edited) Do you prefer your LTR to the banshee you sold? For some things I do.. I like to jump and ride agressively through the tighter, technical parts of the dunes. I can do it more comfortably on the ltr..Basically we like to play follow the leader MX style through the dunes and I'm definetly faster on the ltr..Although not as quick in drag race as the banshee, I don't think it would be too far behind..It would take a near 70hp banshee to pull on me, up the hill...Needless to say, my ltr doesn't have your normal 450 Briggs and Sratton power band, it has some personality. I do 100% for sure miss the banshee though! The sound, the looks, cruising along in third or fourth gear right on the edge of getting on the pipe and you just blip the throttle onto the pipe, braap, braap, braap with that instant rip your arms out of their sockets response...Yeah I miss that...I wish I would have stopped trying to make it faster right when I bolted on the cub cyl..After the porting and override, It just became too much work to be a good dune bike and too heavy to be a good drag bike. Edited February 28, 2012 by Titan up Quote Link to comment Share on other sites More sharing options...
SonOfSand Posted February 28, 2012 Report Share Posted February 28, 2012 For some things I do.. I like to jump and ride agressively through the tighter, technical parts of the dunes. I can do it more comfortably on the ltr..Basically we like to play follow the leader MX style through the dunes and I'm definetly faster on the ltr..Although not as quick in drag race as the banshee, I don't think it would be too far behind..It would take a near 70hp banshee to pull on me, up the hill...Needless to say, my ltr doesn't have your normal 450 Briggs and Sratton power band, it has some personality. I do 100% for sure miss the banshee though! The sound, the looks, cruising along in third or fourth gear right on the edge of getting on the pipe and you just blip the throttle onto the pipe, braap, braap, braap with that instant rip your arms out of their sockets response...Yeah I miss that...I wish I would have stopped trying to make it faster right when I bolted on the cub cyl..After the porting and override, It just became too much work to be a good dune bike and too heavy to be a good drag bike. Perfect description of what I love about riding my banshee in the dunes... I agree, for real fast MX style dunning, 450 based quads are the way to go. Quote Link to comment Share on other sites More sharing options...
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