11 replies to this topic

[darcym]

hi all -

this is a modification I want to do but the stock setup is peculiar to the California TDM. So any Cali TDM owners out there who have successfully done this chime in. Someone else might know what to do if you're familiar with how this all works.

ANYWAY, back in '92 when my TDM was first shipped to California our state had just start to require additional cleaning of fuel emissions for motorcycles. The models sold in other states didn't have these requirements (This only affects motorcycles sold by a dealer -- nobody ever inspects a motorcycle in the US after it's sold, so you can modify it to heck and still get it registered). I'm all for the environment, but the early versions of these emissions cleaning canisters were ugly, clunky, and generally got in the way. I'm also not sure it's all that effective either, and probably has some (although slight) impact on performance. I want to remove it. It's been there 15 years, time to go.

Trouble is, I'm not sure what's going to happen to the hoses if I take it off, and how to reroute them? Or if they're at all necessary?

The canister is in Yellow -- it sits right below the left lower fairing cowl and outside the engine case.
I've colored the hoses Red and Blue to make it easier to follow.

Edited by darcym, 07 May 2006 - 05:14 am.

[dandywarhol]

Looks to me that any fuel vapour has to be collected in the canister (probably find it's full of charcoal).All other TDMs vent to atmosphere. I'd remove the entire assembly and just let the carbs and tank vent out down towards the ground via rubber pipes darkym

Jeezus....next thing they'll be stuffing canisters up cows arses to stop them polluting the environment when they fart

[SteveGlover]

I've never seen an EVAP system before, so the following is given in good faith but without warrenty, etc, etc!!!!

Looks to me as if the red coloured pipe (to carb) is used to draw fuel vapour out of the cannister. If you remove this pipe you will have to block off the connection at the carb. The carb probably has a stub here - a short length of metal pipe sticking out of it where the red pipe joins. Block it off with a rubber plug of some sort.

I would probably leave the rollover valve in place, along with the purple pipe to the fuel tank. The outlet of the rollover value (the blue pipe) needs another pipe adding and routing down below the bike. This will vent the vapour in the tank to atmosphere. So you'll be as dirty as us Europeans!

If the EVAP system is working correctly I can't see that it would affect performance. However, with all those extra pipes connected to the carb, you run a bigger chance of an air leak allowing the engine to run lean.

Hope this helps.

[darcym]

I was pretty much thinking along these same lines, thanks guys.

The trouble is ...

If the canister is using charcoal to clean any unburned fuel vapor leaking from the tank or coming off of the carbs, then it's not really affecting the carb function and the hoses can all be removed and/or capped. If it is using charcoal then guaranteed it's all saturated by now and not doing any good anyway.

If the canister is somehow returning a fuel/air mixture to the carbs from the tank via the canister, and then burning it to prevent leakage into the air, are the hoses into the carb part of it's breathing and will plugging it off starve the carbs of air?

Either way, once it's done, I'll probably have to work on the mixture some.

[SteveGlover]

If the canister is somehow returning a fuel/air mixture to the carbs from the tank via the canister, and then burning it to prevent leakage into the air, are the hoses into the carb part of it's breathing and will plugging it off starve the carbs of air?

I don't think so, the cannister probably contains a "purge control valve" that only lets fuel vapour out under certain conditions. Anyhow, it should be easy enough to try it. Disconnect the pipe from the carb to the cannister, and plug the carb stub. Don't run like this too long though, because the cannister will fill up with fuel.

[stevepsd]

I was pretty much thinking along these same lines, thanks guys.

The trouble is ...

If the canister is using charcoal to clean any unburned fuel vapor leaking from the tank or coming off of the carbs, then it's not really affecting the carb function and the hoses can all be removed and/or capped. If it is using charcoal then guaranteed it's all saturated by now and not doing any good anyway.

If the canister is somehow returning a fuel/air mixture to the carbs from the tank via the canister, and then burning it to prevent leakage into the air, are the hoses into the carb part of it's breathing and will plugging it off starve the carbs of air?

Either way, once it's done, I'll probably have to work on the mixture some.

My riding buddy with a California spec '92 did this mod many years ago when the charcoal canister fell off

Remove and cap the nipple on the carb from the cannister; extend the rollover valve vent tube to below the bottom of the bike - follow the existing carb overflow hoses to where they exit by the right side footpeg. No jetting changes required. The fuel vapor in the charcoal cannister is only drawn into the engine under high vacuum (decel) and the cannister is 'empty' after the first couple of times you close the throttle.

Also don't forget to remove that ugly cannister.

-steve

Edited by stevepsd, 08 May 2006 - 12:09 am.

[darcym]

Steve -

that's great to hear, just what I was looking for! Many many thanks!

BTW - do you know how or what he used to plug the carb where the other hose is?

thanks again -
dm

[dandywarhol]

.......an extra small butt plug might do the trick.......................

[stevepsd]

Steve -

that's great to hear, just what I was looking for! Many many thanks!

BTW - do you know how or what he used to plug the carb where the other hose is?

thanks again -
dm

Remove the hose from the carb and use either a 1/4" or 5/16" (can't remember exactly) rubber vacuum cap over the nipple on the carb, secured by a small clamp. You can get these caps in a small assortment pack for a couple of dollars from any auto parts shops.

-steve

Edited by stevepsd, 08 May 2006 - 11:59 pm.

[darcym]

I got some smallish vacuum caps and installed today, seemed snug though so I didn't use a hose clamp. I wasn't able to route the hose from the roll-over valve as planned because the hose is too thick and won't fit anywhere. Right now the arse end of the valve is sitting somewhere south of the battery box until I can get it fitted with a less bothersome hose.

Started it up after all was put back together and it seems to be running ok and no leaks I can see, but didn't get out on the road yet for a full test. That''ll be tomorrow on the way to work. Last thing to do is to take a hack saw to the mounting bracket for the canister and smooth it out and maybe dab a bit of paint there. Overall I think it was a success!

I'll have pics up in a bit.

But damn I absolutely hate having to take the tank off to do anything on this bike. It's the only thing I really hate about the TDM. I always spill gas and this time I got some small scratches on the tank. I love that the bike is compact but there's no room even for my small hands to get in there to do anything. Plus I'm always worry about stripping out bolts or busting plastic bibs too when there's so many pieces to take off just to do anything - like clean the air filter or change the battery. When I had it all off today I took the opportunity to change a headlight bulb, too. I'm vaguely contemplating keeping the side fairing pieces off altogether.

grrrr ....

Edited by darcym, 09 May 2006 - 07:14 am.

[darcym]

So far so good!

Made it in to work today! Bonus performance boost, too -- seems like now without the canister that low speed/low rev and throttle response seems to have noticeably improved! That's great news if it all holds up - makes the bike infinitely better for my commute.

I'm debating now whether to actually cut off the mounting tab for the disposed of canister. I'll post some pics tomorrow and see what y'all think.

[dapleb]

I reckon if the mounting tab aint in the way or too offensive looking, then leave it there. At least you can go back to charcoal bucket if needs be.