ryskie22 Posted September 17, 2011 Report Share Posted September 17, 2011 ok i have a 421 cub on gas with 39 pwks 160 main and 52 pilots with dek in the middle position, cpis with cascade silencers. the problem is that the motor on the the topend wiill nose over and have a slight miss to it, i have checked all electrical from a known good bike(actually switched everything on it one at a time) now have also tried jetting it down and up with same results so for some weird reson i decided to try me cpi selincers bingo that fixed the problem! i am confused as to why it seems that there is being too much heat being held in the pipe the cascade silencers are bone dry no oil residue at all my cpis are dripping oil. i have taken them apart and found no obstructions just very disscolored packing and burn holes in the front of the packing. when i just cruise around with the cascades on it feels like my head pipes are on fire againts my knees! but with the cpis not so. its geting the spark plug so hot its cracking at the Spark Plug ceramic Insulator and is fine with the cpis. now i know that a lot off people run these type of silencers and i would like too as well if i can figure out what is wrong with them. oh also just let everybody know how my pipes are getting my stinger tubes have full leangth heat sleeves on them and they have burnded through them and into my plastic! Quote Link to comment Share on other sites More sharing options...
RadarRacing Posted September 17, 2011 Report Share Posted September 17, 2011 Porcelain cracking in the plugs is from detonation not necessarily from heat. A hot motor will detonate very easy compared to a cold motor. Something is wrong with those silencers if the CPI ones work fine, they are clogged up or the tube length is longer, tube inside diameter is smaller or something. I would NOT run with those silencers even one more time if it detonates with them on. That will hammer your pistons and domes to death. Quote Link to comment Share on other sites More sharing options...
ryskie22 Posted September 17, 2011 Author Report Share Posted September 17, 2011 Porcelain cracking in the plugs is from detonation not necessarily from heat. A hot motor will detonate very easy compared to a cold motor. Something is wrong with those silencers if the CPI ones work fine, they are clogged up or the tube length is longer, tube inside diameter is smaller or something. I would NOT run with those silencers even one more time if it detonates with them on. That will hammer your pistons and domes to death. my pistons and domes are perfect been running the silencers for two seasons and the silencers are not clogged the perferated tube is spotless like you burned it out with a propane torch but it is longer and the same size in diameter as the cpis. Quote Link to comment Share on other sites More sharing options...
ryskie22 Posted September 19, 2011 Author Report Share Posted September 19, 2011 anybody got any ideas someone has to have ran into this? Quote Link to comment Share on other sites More sharing options...
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