detailbarn 14 Report post Posted April 1, 2007 I just had the local muffler shop put a new exhaust on my 20hp honda , i used a stock honda manifold pipe on the motor which they extended through the floor and into a car muffler from a 4cyl car then over to the side of the trailer. Problem is it now sounds likes a worked Harley coming down the road , I would say loud but that would be an understatement. It's going back to the shop on monday but I'm not sure what do have them do , should i change to bigger muffler? Should I put the stock muffler back on and run two mufflers? Any help is greatly appriciated. Share this post Link to post Share on other sites
PLD 14 Report post Posted April 1, 2007 Mufflers are tuned to the air flow they will handle. If you put too large of a muffler, it acts more like a section of exhaust pipe than a muffler. I'm not sure what the appropriate muffler is, but it sounds too large... Share this post Link to post Share on other sites
Tmrrptr 164 Report post Posted April 1, 2007 The post abt muffler tuned to engine is very correct ! I would suggest an aftermarket exhaust pipe muffler for an offroad motorcycle complete w/spark arrestor. 20hp is abt the 250cc class, or less. My kid has a few out in the garge..... I could look for names, if you wish. r Share this post Link to post Share on other sites
detailbarn 14 Report post Posted April 1, 2007 ok this is very helpful , i had originally though to put a motorcycle muffler on but wouldn't 250 be to small the honda 20 hp is a 750 v-twin? thanks for the help. Share this post Link to post Share on other sites
Christopher 102 Report post Posted April 1, 2007 It might be that the muffler was for a 4cyllinder engine. I have talked to a couple of guys that used a regular full sized muffler and it made all the difference. I have been wanting to try this to quiet my machine. I have the Briggs Vanguard 21hp motor and woud like to try the auto muffler. Maybe this week if I have time. Share this post Link to post Share on other sites
detailbarn 14 Report post Posted April 1, 2007 yeah I'm thinking the 4cyl muffler is the problem , the shop did increase the pipe size from 1.25 to 1.50 then into the muffler and out to 2.0 so it may be a combination of everything. Share this post Link to post Share on other sites
Douglas Hicks 128 Report post Posted April 1, 2007 Some time ago, a post was made about this subject. That person used a muffler from a B210 Datsun. For you young guys, that is what Nissan used be known as. Share this post Link to post Share on other sites
detailbarn 14 Report post Posted April 2, 2007 well it goes back to the muffler shop tomorrow , hopefully they will be able to correct this in a timely fashion , I will post updates tomorrow. If anyone has suggestions feel free to continue with them because I don't have much to go on yet. Share this post Link to post Share on other sites
PressurePros 249 Report post Posted April 2, 2007 Tim the toolman would probably tell you its perfect as is. Share this post Link to post Share on other sites
Scott Stone 604 Report post Posted April 2, 2007 Honda has a muffler made for teh 20 hp. It is quiet though not silent. Share this post Link to post Share on other sites
detailbarn 14 Report post Posted April 3, 2007 so the muffler shop was able to fix the harley sound coming from the muffler , how? By putting two mufflers on a V8 unit and a 4cyl , sounds great now not silent but much quieter and outside of the trailer. I'll post some pictures of the setup later. Thanks all for your help. Share this post Link to post Share on other sites
