ds80 problemo's

[GooseMan]

I'm a little bit stumped with my little brain teaser here, so was wondering if you guys could help?

Firstly the bike was missing a bolt out of the exhaust where it bolts onto the cylinder because the thread inside was stripped, it held on ok with one bolt but a small leak, which was to be expected.

I kept putting off the fix until my friend bottomed it out and broke out the other thread So I repaired the threads with a thread insert. It worked well, no exhaust leak no nothing. Problem is though it just doesn't seem to have the power it used to now that it is fixed up. I would have thought this would have given it more back pressure and more power? No? Just curious as to why this has happened.

Cheers,

 

[my67xr]

have you cleaned the expansion chamber out yet? burn the oil/carbon out
mine wouldn't rev past 1/2 throttle it was so bad.
start it with the header pipe off, just for a few seconds, see if it revs freely

 

[timeeh]

have you cleaned the expansion chamber out yet? burn the oil/carbon out
mine wouldn't rev past 1/2 throttle it was so bad.
start it with the header pipe off, just for a few seconds, see if it revs freely

What he said... At a guess it wasn't sealing properly with the bolt missing, and now that is properly sealed the exhaust gas has nowhere else to go but through the pipe, which sounds as though it is blocked. Also backpressure doesn't equal power as such, headmess wrote a good write up on how a expansion chamber works a while ago, but i'm not even going to attempt to explain it, worth a read though if you can find it.

 

[Chronic]

Burning out the expansion chamber is wicked fun!

 

[GooseMan]

yeah expansion chamber was burnt out and cleaned before it was put back on, an I did read the whole headmess expansion chamber thread and most importantly understood it,lol. This will still rev almost right out but it is much slower to get there. It deffinetly does not sound like a carby issue but more like the back pressure is almost not tuned right for this engine. Maybe I should have another look into getting a rm80 exhaust for it as I have heard they will make it goes much better.

 

[heliboy89]

How do you burn out the expansion chamber exactly? Maybe this is worth doing for my DS80 Goose/67/Chronic...?

Sorry if it has come up already but did you try clearing the baffle? Take the bold out from under the end of the flame suppressor and a cap comes out, then baffle, then inner pipe, and the baffle has small sections that spin the gasses which tend to choke up regularly on DS80s...

Worth a shot...

 

[zwebx]

How do you burn out the expansion chamber exactly? Maybe this is worth doing for my DS80 Goose/67/Chronic...?

Sorry if it has come up already but did you try clearing the baffle? Take the bold out from under the end of the flame suppressor and a cap comes out, then baffle, then inner pipe, and the baffle has small sections that spin the gasses which tend to choke up regularly on DS80s...

Worth a shot...

You can do it with a gas torch.. i like to do it this way..
step one: grab phone.. call mates to come over with a decent ammount of beer
step two: drink alot and then make a bonfire.. and yeah chuck the pipe in and watch it (turning it maybe to make sure its all burnt) that may burn it out.. and you will want to respray it afterwards
not recommended to do on weekdays but each to there own
a gas torch means you can be more accurate and less intoxicated (whats a bonfire without beer and mates)

 

[heliboy89]

I can't help but feel like, if I were to cook the pipe on a fire, then take it back to something worth painting on, there would be nothing much left of it lol? do you sand blast it or anything before respraying?

Your method does sound fun though.

Sorry to hijack the thread!

 

[GooseMan]

I used a propane torch and compresed air, although I found the propane a bit weak so a gas torch would be better. Heat the header end of the pipe at the entrance so that it is ambering and really hot, add compressed air slowly and gently while still burning the carbon build up, the air should blow the heat up the pipe and burn the rest out. It didn't really work that well for me as the wasn't enough carbon in there to burn out.

 

[GooseMan]

With the baffle I wasn't too sure how to clean it properly, can't remember exactly what I did but I know I pulled it apart like you siad and wire brushed all the parts (which is only really cosmetic) and I might have soaked it in soapy water over night. Although I don't think this will be the problem your having, but it wouldn'd hurt to do it.
You can see it apart in my ds80 thread in my signiture below.

 

[zwebx]

With the baffle I wasn't too sure how to clean it properly, can't remember exactly what I did but I know I pulled it apart like you siad and wire brushed all the parts (which is only really cosmetic) and I might have soaked it in soapy water over night. Although I don't think this will be the problem your having, but it wouldn'd hurt to do it.
You can see it apart in my ds80 thread in my signiture below.

if its anything like the old 2t mufflers you may need to cut it.. then you can just clean the pipe in a fire then re-pack it with new stuff

 

[GooseMan]

This is what it looks like.....

 

[heliboy89]

I've only got propane up here, no bottles for the oxy kit. Dad has a nice big torch for sterilizing our plant grafts, shoots a nice loud 2 foot blue flame - ought to be worth a shot. I'm pretty certain I'm dealing with a mixture problem but this maintenance does sound fun haha... May I'll run it rich and build some carbon up just so I can do it properly ^^

 

[zwebx]

I've only got propane up here, no bottles for the oxy kit. Dad has a nice big torch for sterilizing our plant grafts, shoots a nice loud 2 foot blue flame - ought to be worth a shot. I'm pretty certain I'm dealing with a mixture problem but this maintenance does sound fun haha... May I'll run it rich and build some carbon up just so I can do it properly ^^

That will do it hopefully

 

[Chronic]

just make sure the neighbours dont have their good white sheets on the washing line lol

 

[GooseMan]

lol^
just try not to melt the pipe with that two foot flame your swinging:grinning-smiley-003

 

[heliboy89]

Well it's a 2 foot propane flame haha. Propane and atmosphere, it's just a lot of it. It will get the pipe glowing, I guess that is hot enough? About spot on is it?

 

[GooseMan]

yep sounds good

 

[heliboy89]

Well you weren't kidding... That's fun as sh!t ...

That's the torch I was using, probably not an overkill really it was about spot on I think;


I got the pipe hot and it started out as a stinking mess as you said it would but it eventually caught fire inside it and blasted it out nicely, that pic below is just plain atmosphere going in one end and look what its dragging out...


http://www.youtube.com/watch?v=rb4y51qTRP4 - This wouldn't happen without a fair bit of carbon in there, right?

I cooked the baffle the same way, spent about 15 minutes pumping thick blue smoke out, I couldn't get air to flow nicely into the grill of the baffle so that's why it took so long. I think it's well worth doing though - if the bike isn't performing well on the top end. Take baffle out, take baffle housing out, then cook all 3 separately - mine looked pretty clear (except for the baffle) but so much crap came out of all 3 components. I didn't think the pipe was choked up too but it appears it was...

 

[heliboy89]

And just to update, got the pipe back on and the bike is making more power than I ever remember it did haha. Can feel the wheel lifting in second and third gear still.