Could this be my problem?

[Wm Holden]

Ok I will clean out the exhaust as well. I was thinking about replacing it with an SBP expansion chamber anyway. The muffler is only a month or so old though so I don't know how much it could have clogged up by now.

Alot of us gut the muffler....but then i stuff steel wool back in to quiet it down...I live in a small town in a condo complex..and well..I don't want to draw attention...I don't really get much of a performance hit from the steel wool...seems like plugging the exhaust would be bad...oh well

 

[nightcruiser]

Alot of us gut the muffler....but then i stuff steel wool back in to quiet it down...I live in a small town in a condo complex..and well..I don't want to draw attention...I don't really get much of a performance hit from the steel wool...seems like plugging the exhaust would be bad...oh well

Watch that muffler full of steel wool, it can clog up quick.....

 

[nightcruiser]

Alot of us gut the muffler....but then i stuff steel wool back in to quiet it down...I live in a small town in a condo complex..and well..I don't want to draw attention...I don't really get much of a performance hit from the steel wool...seems like plugging the exhaust would be bad...oh well

I think everyone was assuming the muffler had been run as long as the piston.....

 

[Cyclin]

I think everyone was assuming the muffler had been run as long as the piston.....

Sorry I didn't make that more clear. This is actually my third muffler on this build. The original and its factory replacement both fell off while riding where the pipe meets the chamber. My welder at that time told me it was due to the pipe being too thin to support the weight of the chamber when vibrating. I secured the chamber of the third more securely to the frame with a bracket and I haven't had that problem since.

 

[nightcruiser]

Not to change the subject, but I was wondering before you ripped the top end apart did you check out the carb, clean it, the air filter etc to see if your performace was suffering due to poor carb performance? What kinda carb do you have? (I am guessing NT or Speed carb since you seem to have had it a while?) Also, did you check into the plug, boot and wire to see if any of that could be the source of your performance drag? I know the stock boot and wire are garbage, and the plug they give you with the kit isn't great either.....

 

[Cyclin]

Actually it is a Dax RT carb and only about two weeks old. It has been installed for a little over a week but the performance loss was happening well before I installed it. I love the Dax RT it has much better throttle response than my NT but with the engine itself running badly it ddin't add too much peformance at the time. The carb itself does have an leak somewhere in it I am pretty sure, I found gas gathering underneath the bowl/bottom of the carb where it dripped off. I am going to take it apart and seal it up with permatex today. I had thought that the cdi could have gone bad as well because the last run I heard a pop and then got no spark whatsoever. It is the original except for the boot which I took off an old junked lawnmower. I have a replacement cdi at the house which last night I took off the original boot and wire, and replaced it with a better performance Magnecore wire and boot. I'm gonna throw that on today when I get home, had to wait for the permatex to dry cause I used it to better seal where the wire meets the cdi. I havent used the original spark plug in months. switched originally to a champion CJ7Y (I think) but have since switched to a NGK B6HS

 

[nightcruiser]

Actually it is a Dax RT carb and only about two weeks old. It has been installed for a little over a week but the performance loss was happening well before I installed it. I love the Dax RT it has much better throttle response than my NT but with the engine itself running badly it ddin't add too much peformance at the time. The carb itself does have an leak somewhere in it I am pretty sure, I found gas gathering underneath the bowl/bottom of the carb where it dripped off. I am going to take it apart and seal it up with permatex today. I had thought that the cdi could have gone bad as well because the last run I heard a pop and then got no spark whatsoever. It is the original except for the boot which I took off an old junked lawnmower. I have a replacement cdi at the house which last night I took off the original boot and wire, and replaced it with a better performance Magnecore wire and boot. I'm gonna throw that on today when I get home, had to wait for the permatex to dry cause I used it to better seal where the wire meets the cdi. I havent used the original spark plug in months. switched originally to a champion CJ7Y (I think) but have since switched to a NGK B6HS

OK, sounds like you have covered all the bases man, new muffler, new carb, quality wire, plug and boot, same performance so I guess none of those items were your problem. I never have had (or even seen) an RT carb, but if it has an overflow like the CNS you might check the float adjustment if you have fuel leaking from the carb. My CNS leaked like crazy, wasnt a bad seal or anything, float was letting fuel go too high in the bowl and it was splashing out the overflow. Good luck, and keep us posted on your progress. I like to follow up on threads like this so I can learn from others experience....

 

[Cyclin]

Ya I had read on here somewhere that there were some tricks for leaky RT carbs, gonna search them out again today. Some people even had to bend the float arm a little to get it working optimally. It is really annoying though that these things keep happening. For instance, I can't even check if the piston buildup and rings were the source of my problem until I can get this build to spark again. So once I get a spark we will finally know if these were the cause of why I started the thread in the beginning haha.

I installed that new engine I bought on the build but remained having no spark. I have put the original engine back on as it is obviously not the cause of lack of spark and moved the new engine onto another bike. If all of the above fixes fail me I will put on my old stock NT carb to troubleshoot if that is the problem while fixing the RT. Thanks for sticking with me on this one I will definately post again with todays tinkering results.

 

[Cyclin]

Hey night so I got the new engine running great. Turns out the problem was the killswitch so I believe that is the problem I was having with no spark on the first bike. Going to disconnect and see how she runs. Only problem is that I now have two builds and only one clutch lever/cable and throttle/killswitch to go around. The originals were really torn up hence why I replaced them in the first place. They are in semi-working condition but were left behind when we moved to a new house 2 and a half weeks ago. I will see if I have time to move the working ones to my 2000+ mile engine build tonight. Finally I will be able to see if all that engine stripping and piston cleaning was worth it! Like I said though, hope I have time to tonight if not then this weekend. My lovely pregnant wife goes to and gets off work early in the morning so she gets allll day to think of stuff that only I can do haha.

 

[killercanuck]

Check out Dax's parts page, clutch handle $5, proper throttle cable $5, etc.
That's Dax, grab some other goodies while you're there to save shipping.

I'd mention others, but RT=Dax, eh? Check out other sponsors for cheaper shipping if you happen to be close to somebody or a sale, bonus.

Oh yea, with the throttle housing apart, you can get at the guts of the kill switch with a Phillips. To check for corrosion/crud/contact.

gl.

 

[Cyclin]

Oh ya I am a big Dax fan. I actually just ordered a new fuel valve from them this morning. I definitely should've grabbed some of their other parts but it was a quick shopping time limit on my break. I have the Dax RT carb and I love it. Plus their customer service is awesome.

 

[killercanuck]

ahhhh, you could've saved so much on shipping, arrghh. (That's just my Dutch/Sottish blood talking)

Keep us posted on how it goes! ^^)

 

[CTripps]

Sorry I didn't make that more clear. This is actually my third muffler on this build. The original and its factory replacement both fell off while riding where the pipe meets the chamber. My welder at that time told me it was due to the pipe being too thin to support the weight of the chamber when vibrating. I secured the chamber of the third more securely to the frame with a bracket and I haven't had that problem since.

My muffler snapped it's support, and shook it's end cap off (twice, loosened the baffles the first time, lost them the second). I ended up drilling and screwing the tube and caps together. I made a muffler support, but it snapped that one as well, so I came up with something else, and it it's been great ever since. I used metal strapping (the stuff used to bind heavy machine parts etc. to pallets) to make the bands for the muffler and the frame.

 

[Cyclin]

ahhhh, you could've saved so much on shipping, arrghh. (That's just my Dutch/Sottish blood talking)

Keep us posted on how it goes! ^^)

Gah I know! The shipping was a little over twice the cost of the part. My wallet is still giving me dirty looks.

CTripps thats an awesome idea for muffler support. I like the spring I'm sure that helps immensely with the vibrations the little engine make. I actually fabbed my own out of air duct clamps after the 2nd weld-snap.

So I finally met another builder in town today! Albeit was due to me breaking down on the side of the road. (Some spokes got loose and in the matter of 20 minutes and a chain slip my my rear rim was wayy warped.) So I am fiddling with my chain and he pulls over saying he's seen me riding on a few occasions. Turns out he had a spare rear wheel with a sprocket already installed! I think he was just as stoked to meet a fellow builder because he just swapped it out on the spot and gave me his number so I can get my tire back once I get a replacement. He totally saved me from a long pedal, I was right in the middle of a 13 mile ride. As you all know, pedaling 6 1/2 miles on these bad boys is awful.

 

[nightcruiser]

Gah I know! The shipping was a little over twice the cost of the part. My wallet is still giving me dirty looks.

CTripps thats an awesome idea for muffler support. I like the spring I'm sure that helps immensely with the vibrations the little engine make. I actually fabbed my own out of air duct clamps after the 2nd weld-snap.

So I finally met another builder in town today! Albeit was due to me breaking down on the side of the road. (Some spokes got loose and in the matter of 20 minutes and a chain slip my my rear rim was wayy warped.) So I am fiddling with my chain and he pulls over saying he's seen me riding on a few occasions. Turns out he had a spare rear wheel with a sprocket already installed! I think he was just as stoked to meet a fellow builder because he just swapped it out on the spot and gave me his number so I can get my tire back once I get a replacement. He totally saved me from a long pedal, I was right in the middle of a 13 mile ride. As you all know, pedaling 6 1/2 miles on these bad boys is awful.

Thats was awesome of him to help you out like that, kinda cool how this hobbie helps you meet cool people. I have met a few since I've been riding too, best I got so far is a nice gas cap though... LOL (Thanks Jim!)
I hear you about the long pedal, I was kinda shocked at first how different pedaling feels after I put the motor on the bike. Since then I have made a small spacer for the rear motor mount that put just enough tension on the chain so I could eliminate the chain tensioner, once that was gone the bike pedals almost as easy as it did before I put the motor on. HUGE improvement in every way running without the tensioner....

 

[killercanuck]

Right on, he was probably just as excited to meet another builder Pedaling sucks, for sure. Especially when the seat height is set for flat feet and not leg pumping. When my other engine locked up I was about 4mi out of town still. Ended up just taking the chain right off, heh heh.

Cool muffler support btw