brian Posted November 6, 2007 Report Posted November 6, 2007 Ok. I just got the 4mil running and took it for a thrashing at Lil Sahara this weekend. It ran really strong for the most part, but there are still a few adjustments to make. Just not as strong as I thought it should be. It pulls hard on the pipe for 1-5 but will not stay on the pipe in 6th gear ? :shrug: The few times I tried I was riding into a 10-15mph wind, but I'm not sure that much wind would cause that effect. I know my jetting is rich, but I guess I want some opinions from you guys whether it is so rich that it would cause it to be that weak. I did not do a plug chop (didn't have time) just set it rich, to be safe, and went. The plugs come out a tad wet and dark chocolate brown after a 20 min. ride and it smokes most of the time. My mods are as follows : 4mil crank. Stock Cylinders dune ported(mild according to Jim @ PRE). Custom Coolhead :thumbsup: with 20cc domes. CPI Inframe drag pipes. 35mm PWKs. K&N pods with Outerwears. Running VP110 with Ktotz Supertichniplate. I don't have compression numbers yet, will try to test it this week. Jetting: 45 pilot (still too rich-I got 3 turns on the screws and the idle speed screws most of the way in) 2nd deck (from blunt)on needle 160 main I bought the carbs with a jet kit. The carbs were preset with a 48 pilot, 160 main, deck 3, and 2 T/O. 45 was the smallest pilot in the kit and 160 is the smallest main, so I gotta get sum jets anyway. Quote
Bansh-eman Posted November 7, 2007 Report Posted November 7, 2007 that motor at sea lvl should be around 150-155 main 45-50 pilot 3rd clips 2/5 turns.... having it as rich up top could be whats killing your topend Quote
brian Posted November 7, 2007 Author Report Posted November 7, 2007 I guessed that, but do you think that much ? Quote
dajogejr Posted November 7, 2007 Report Posted November 7, 2007 Ask Jim @ Passion what he thinks your jetting should be. It's his motor and he should be able to tell you where it likes fuel. I didn't have that big of mains in my 4 mil cub when I had 35PWKs...so, I think you can go leaner, but ask him. Keep in mind, it takes a good motor to pull 6th gear in sand...but...a properly jettied and geared dune ported bike such as yours should pull it no problem. By the way, just out of curiosity... What gearing are you running, what size rear tires, how much air pressure and how many paddles? That has a TON to do with it as well. How much timing are you running? And...last but not least, let us know how much compression you're running.... Quote
brian Posted November 7, 2007 Author Report Posted November 7, 2007 (edited) By the way, just out of curiosity...What gearing are you running, what size rear tires, how much air pressure and how many paddles? That has a TON to do with it as well. How much timing are you running? And...last but not least, let us know how much compression you're running.... The funny thing is that the previous POS motor would pull 6th gear. With a good start, I could even pull 6th up Test Hill out at Gordon's Well in CA. Not actually Jim's port. I just took some measurements and he ran them through his porting software to come up with port timing numbers. Based on those numbers he told me the porting is fairly mild. Still it's a good idea, he could probably give me an idea on the jetting. I set up the timing at 6 deg. advanced. The paddles are sand stars with 4 psi, so I think they're 8 paddles but not the same as haulers. I want to use 10 paddle haulers, but I think I need to figure this out first. If it cant pull these sand stars, it will never pull 10 paddle haulers. I am running a 13 tooth primary sprocket with the stock rear (41 I think). I knew you were gonna ask me bout the compression again. LOL I promise, I'll get it this week BTW Dave, I'm going to Lil Sahara again this coming weekend ! :tongue: Wish you could be there ! I'll be thinking of you when I'm shredding the faces of those dunes. LOL :yelrotflmao: Edited November 7, 2007 by brian Quote
brian Posted November 7, 2007 Author Report Posted November 7, 2007 (edited) BTW Dave, I'm going to Lil Sahara again this coming weekend ! :tongue: Wish you could be there ! I'll be thinking of you when I'm shredding the faces of those dunes. LOL :yelrotflmao: I know that was uncalled for, but I couldn't resist !!!!!!!! LOL Edited November 7, 2007 by brian Quote
dajogejr Posted November 7, 2007 Report Posted November 7, 2007 Hey....no problem. Unfortunately, my dune/sand season is over....so, I'm gonna have to wait for a lake to freeze...LOL.... Have fun and be careful... Quote
brian Posted November 9, 2007 Author Report Posted November 9, 2007 Ok Dave, Finally got the compression tested. LOL 155 psi both cylinders, give or take 1 or 2 psi. Quote
J-Madd Posted November 9, 2007 Report Posted November 9, 2007 13 tooth? That killed one of my CUB motors, granted it should let you pull a higher gear. I had other issues as well. .....My stock stroke Cub never pulled 6th. It would fall on its face every time..I gotta 1-5 override now so I never see 6th Quote
brian Posted November 9, 2007 Author Report Posted November 9, 2007 13 tooth? That killed one of my CUB motors, granted it should let you pull a higher gear. I had other issues as well. .....My stock stroke Cub never pulled 6th. It would fall on its face every time..I gotta 1-5 override now so I never see 6th How did the gear kill your Cub ? I never heard of that. Quote
brian Posted November 13, 2007 Author Report Posted November 13, 2007 Finally got that jetting dialed in right. :biggrin: Yeah, that thing pulls like crazy ! No problem running out 6th ! Aside from a couple of full on drag banshees, and a YFZ 450 on the bottle, there werent too many other bikes that could outrun it. Now that that works, gotta start the next project........... :beer: Lotsa beer ! And tryin to break it again. LOL Quote
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