Exhaust Exhaust BLEW Off?!

[slaquers]

Exhaustblew off last night...it ran much "better" but louder w/o exhaust. How did this happen? I think the nuts werent tight enough, theexhaust just blew off nuts and gasket and muffler, I found it and re attached and re tightened it. What could cause this? Engine seems fine now though. Lost the little ceramic plate....can I run it without this?

Also I noticed it was shooting gas from the exhaust when it was off, running too rich or too lean?




Thanks! My first one still needs work...

 

[AussieSteve]

You need a bracket to take the weight of the pipe. It's not good to just hang it off the studs.
What ceramic plate?
You didn't mention which engine type, or even if it's 2 or 4 stroke.
This thread would have been better in the appropriate '2-Stroke Engines' or '4-Stroke Engines' section.
Without exhaust back-pressure, you can expect a 2-stroke to spit some fuel from the exhaust.
Even when set up properly, they spit some out and some out of the inlet.

 

[slaquers]

Sorry I am new to MBs and engines in general.

2 Stroke Chinese China Gas Skyhawk GT5 slant
On a old Huffy frame
Needs back wheel bearings, and brakes

Other then that seems ok -

I think I had the plate (ceramic) and it blew off with the exhaust but hm ok.

Any FAQs/tips for tuning 2 stroke Skyhawks?

Is pretty much "stock".

 

[Dilly Bar Rob]

Perhaps the nuts stripped? Dont forget that the factory mounting hardware on these is made of steel with (at least) 30% butter content If you mean that the gasket went missing don't worry, I have used high temp silicone (ultra copper) to seal the exhaust flange, still holding after a few months.

Gas shooting out with no exhaust is normal, that's why you need some muffler/pipe on there (back pressure) , to keep help that gas mixture in, otherwise you will run lean.

The muffler on my last HT build blew off where the pipe is welded to the muffler body, after this I fabbed up my own muffler/pipe as I didn't want to try and weld the thin chinese pipe. Lucky that I had the muffler supported by the bracket going to the frame, now I know why they want you to have that bracket there....If I didn't have it the muffler would end up under the rear wheel, not good. I ask my self "now how did THAT happen", as the engine was practically new when it happened... I guess that the kid behind the mig welder at the factory just wasn't having his day when he welded it...

 

[AussieSteve]

2 Stroke Chinese China Gas Skyhawk GT5 slant
Needs back wheel bearings, and brakes

Fix them brakes, you'll need them.

I think I had the plate (ceramic) and it blew off with the exhaust but hm ok.

I guess you mean the exhaust gasket, (not ceramic).

Any FAQs/tips for tuning 2 stroke Skyhawks?
Is pretty much "stock".

Here's a link to get the ball rolling:- NT Carb Tuning Basics.
Also, match the ports to the inlet and exhaust. (A search will turn up info on this.)

 

[rookie6453]

Mine broke by the muffler just welded it back the nuts on the exhaust need to be replaced for sure all the mounting hardware should be trashed and replaced during the build and loctited in. Also checked regularly before a long ride.

 

[slaquers]

Okay so I bought a bike at Wal Mart and I am going to swap it to this bike.

I bought a Huffy "Cranbrook" looks like I have to drill the frame :[


http://slaquenet.com/bike2.jpg is the bike it is on now, another Huffy...they look 100% the same actually.

-slaquer

Also thanks for NT carb tuning link.

 

[cabinfever1977]

You can use a clamp and metal plate instead of drilling.

You 2 nuts on each stud,called double nutting,helps to hold muffler on.