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TOPIC: Re:Sputtering when coasting Forum Tools Post New Topic Show latest posts Rules

#990949 Clongo (User) Fresh Boarder Posts: 8 Re:Sputtering when coasting 1 Year, 4 Months ago   The new parts final arrived and I installed them this morning. Took the bike out for a short ride and there seems to be some improvement. I'll be going on a long road trip tomorrow so that will be the true test. This is the old part. You can see the small crack in the middle. I'm glad I also ordered a new spring and diaphragm. The old spring was about a quarter inch short from 14 years of compression. If you can get your hands on one of these right angled screwdrivers it made the job much easier. Not sure where you can get one. I've had this one for 35 years and I got it from my grandfather.   Logged     Last Edit: 2016/10/30 16:38 By Clongo.   The administrator has disabled public write access. #992028 Clongo (User) Fresh Boarder Posts: 8 Re:Sputtering when coasting 1 Year, 3 Months ago   Here are the pictures that were missing from my last post.   Logged     Last Edit: 2016/11/03 18:44 By Clongo.   The administrator has disabled public write access. #992029 Clongo (User) Fresh Boarder Posts: 8 Re:Sputtering when coasting 1 Year, 3 Months ago   Picture number two.   Logged     The administrator has disabled public write access. #992307 Clongo (User) Fresh Boarder Posts: 8 Re:Sputtering when coasting 1 Year, 3 Months ago   Still experiencing sputtering while coasting (1/4 throttle), popping and backfiring when decelerating. If I leave the choke knob out about 1/4" it minimizes the sputtering and eliminates the popping and backfire. As previously mentioned I have a Kuryakyn Twin Velocity air box and Cobra exhaust w/o baffles 2 1/2" diameter pipes. I'm going to order a Baron's jet kit. Is that a good kit? Is there a better one I should consider. I read another post that had a similar setup to my bike and they were located here in S. Florida so the atmospheric conditions should be the same. They use the following setup. Does this setup sound right? Does anyone have a better recommendation? PMS: 2 1/2 turns Needle: 4th slot from blunt end Main: 172.5 or 170 Pilot:35   Logged     The administrator has disabled public write access. #992362 SKWEARpeg (User) Platinum Boarder Posts: 12885 Re:Sputtering when coasting 1 Year, 3 Months ago   I think I'd start looking for air leaks where the intake manifold connects to the heads. It sounds like you may have a vacuum leak there. With the throttle closed or nearly closed, the vacuum spikes in the manifold. By adding enrichment, your covering for the lean condition caused by the possible leak.   Logged       The administrator has disabled public write access. #992697 Curt (Moderator) Never to old to ride! Moderator Posts: 22378 Re:Sputtering when coasting 1 Year, 3 Months ago   Un-baffled pipes don't help Get some kind of restriction to put in the end like the Thunder Monster Baffles. The sound good and are loud enough but do give back pressure. Check the pipes at the head joint with an insane stick for leaks those too will cause your problem. You should be close on the needle you may need to reset it. I will e-mail you the method that have written up. PM me your e-mail address.   Logged     Last Edit: 2016/11/10 13:45 By Curt.     The administrator has disabled public write access. #992703 Jclevesque (User) Platinum Boarder Posts: 1461 Re:Sputtering when coasting 1 Year, 3 Months ago   SKWEARpeg wrote: I think I'd start looking for air leaks where the intake manifold connects to the heads. It sounds like you may have a vacuum leak there. With the throttle closed or nearly closed, the vacuum spikes in the manifold. By adding enrichment, your covering for the lean condition caused by the possible leak. +1 on the air leak if added the enricher stops it.   Logged       The administrator has disabled public write access. #992826 Flashback (Moderator) Just the facts, Ma'am.. Moderator Posts: 10749 Re:Sputtering when coasting 1 Year, 3 Months ago   Curt wrote: Un-baffled pipes don't help Get some kind of restriction to put in the end like the Thunder Monster Baffles. The sound good and are loud enough but do give back pressure. Check the pipes at the head joint with an insane stick for leaks those too will cause your problem. You should be close on the needle you may need to reset it. I will e-mail you the method that have written up. PM me your e-mail address. +1 but I think he meant incense stick.... Also the ais should be removed if it isn't already............   Logged       The administrator has disabled public write access. #994173 Clongo (User) Fresh Boarder Posts: 8 Re:Sputtering when coasting 1 Year, 2 Months ago   Looks like my jets and fuel mixture are just fine. Checked for manifold leaks and there were none. Ordered a set of Big City QQ Thunder Monster Baffles and that seems to have done the trick. I'm still getting a little bit of popping when decelerating but the hesitation and sputtering is gone. I suspect I just need to adjust the position of the baffles. Currently I'm using an existing hole in the exhaust pipes that is 3" from the end. The instructions that came with the baffles recommend 6" from the end for optimum performance and sound. The new sound is also a big plus. Before the pipes just had an obnoxious BLAAAAHHHHHH sound. The baffles are still loud but have a more throaty tone that I really like. Thanks for the advice Curt.   Logged     Last Edit: 2016/11/26 20:39 By Clongo.   The administrator has disabled public write access. #994222 davej (User) Platinum Boarder Posts: 18167 Re:Sputtering when coasting 1 Year, 2 Months ago   Clongo wrote: I'm going to order a Baron's jet kit. Is that a good kit? Is there a better one I should consider. I read another post that had a similar setup to my bike and they were located here in S. Florida so the atmospheric conditions should be the same. They use the following setup. Does this setup sound right? Does anyone have a better recommendation? PMS: 2 1/2 turns Needle: 4th slot from blunt end Main: 172.5 or 170 Pilot:35 The Barons kit is the recommended jet kit but that is not the correct jetting for your bike. Now that you have installed baffles you should run either a 167.5 or a 170 main jet along with a 37.5 Mikuni pilot jet (sold separetly), clip in the 4th slot and PMS at 2 1/4 - 2 1/2 turns out. Is your Cobra exaust just slip on mufflers or a whole system front to back? If it is just slip on mufflers you will find out that the Cobra's are problematic at best   Logged     Last Edit: 2016/11/27 07:18 By davej.   dave   The administrator has disabled public write access.

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