jst854

The CDI is brand new and the coil is good, I switched it out from my brothers bike which is running good so I know that is good.

I am around 1000ft for elevation. The plugs are 8's, the engine is fresh, brand new crank, pistons, head, carbs, and pipes. The filters are clamp on's with prefilters. I have a oversized petcock and the stock vent on the fuel cap, could that keep it from getting enough fuel? I have not checked the plug boots yet, I will switch them out for a pair that I know is good. I do not have room to do a plug chop around here so I can't get a accurate reading on the plugs.

yes I did a leak down test and it held 5 pounds for 5 mins what would you recommend as a starting point?

I have been trying to get this bike jetted for about a month now. It is a 4 mil long rod with the domes cut, dont remember the dome size but it has about 160 psi and i am running 114. It has a cool head, VF3's, timing +4, very close to a full out drag port, CPI inframes, and 35mm mikuni carbs. Currently I am at 70's for the pilots and 580 at the mains. The clip is in the bottom position. This is by far the best it has run with the jetting as I have tried everything from 200 through 600 and 30 through 80 for the pilots. The bottom end is good but as soon as it hits the power it seems to not want to pull and sputters. Here is a short video of it. Let me know what you guys think as I am stumped.

I started making my way back down and I am at 270's now and it is starting to run a little better. It just seems weird that this set up would take such small jets. Is there something different about bigger carbs that make up for smaller jets?

I am also running 2 clamp on filters with prefilters, so no airbox at all.

Sorry for the spelling and grammar mistakes, i typed that from my phone. But the Carbs are Mikuni's. When I had the 310's in the bike ran a little bit better on the top but no where near perfect when I had the choke on. When I switched to the 410's it seemed to run the same as with the 310's in it. It could get into the powerband range but did not have any pull at all like it should. So I am thinking that the 310's where too lean and that the 410's where too rich. What do you guys think of that?

They are mikuni and with the 300 it seemed to rev out a little better with there choke on but would not idle under half throttle. I did not try the choke with the 400s in there.i am thinking I might try some 360 and see how that works but that seems kind of lean yup me. What do you guys think?

Here is what I have, a 4 mill long rod stroker, aggressive port, not quite a full out drag port though, 34mm carbs, and cpi inframes. Where should I start for jetting, I have a 410 in there now and I cant get any top end, the same happened with 310. any suggestions

I am just getting my shee together finally and ran into a problem when trying to get the carbs on. THey are 34mm Mikuni Flat slides and I have the banshee manifold ( intake boots) for a PJ34, PWK 33-35 and the carbs physically fit in the boots, however the bottom of the carbs are hitting the clutch cable and clutch lever on the case by a good half of an inch. Is there something I am doing wrong, or some special trick to this?

I did use this cable but it seems too short, almost like the carbs are at 1/4 throttle with out even pulling the throttle. I am also having problems mounting the carbs. I have the carb boots for PJ34, PWK 33-35 and the bottom of the carbs are hitting the clutch cable and clutch lever on the case, is there a special way to mount these?

I just got a set of 34mm Mikuni Flat Slides carbs and was wondering what throttle cable i have to use with them. I currently only have a tors throttle cable and that obviously doesnt fit, Does a stock throttle cable w/ tors eliminated work with these carbs, if not where could I find a cable that will work. Thanks

I do not know how SLP is with ATV Products, but they are very well know in the snowmobile industry. I have a ton of SLP Products on my sled including a pipe and can and will say that I am very happy with it and it does have very noticeable gains over stock.

Thanks for the help and the engine is a 4mil stroked long rod bringing the engine up to about a 403. John at Gassrx did all the engine work. It will be running CPI inframes with 35 carbs. Should have it all back together in about a week or so

I just got a +4 swing arm for my shee as I am building it from the ground up and need help finding a chain as well as a good baseline for the gearing. I know the chain is 520 pitch but how many links will be needed for a + 4 swing arm. I will have around 70 HP and plan on dragging it in the 1/8 mile and was wondering what gear set up would best suit me, I am pretty sure that I have 20 inch tires, I will double check that tonight though. I also have the option of running on alky and my engine builder told me to expect around 95 hp that way, not sure if I want to go that route or not yet as this is not strictly a drag bike, but if I were to do that should I run taller gears than if I ran it on gas?

I need a pair of stock jugs ASAP. Please email me at justinklumb@hotmail.com if you have a pair you are looking to get rid of. Thanks Justin