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2009 Sprint ST Stinky Exhaust

3K views 17 replies 8 participants last post by  turboLT 
#1 · (Edited)
I'm trying to figure out how to fix my '09 Sprint ST which smells like it's running very, very rich. Riders behind me (and now pedestrians crossing in front of me!) complain of the exhaust smell, I get backfires relatively frequently on engine braking, there is black soot all over the back of the bike and my stuff smells like exhaust.

About the bike:
The previous owner opened up the airbox and the exhaust canister so it flows more air. They also removed the SAI and I believe and flashed a new tune. Finally, it has a Daytona 675 intake cam. There are no check engine lights. Bike has about 27,000 miles. I get around 40 (US) mpg highway but only 20 or so city. 91 Octane gas here in California. I ride a lot so it's worth a lot to me to fix this if it's at all feasible.

I'm thinking I could
1. reinstall the SAI
2. Take it to a shop and ask them to see if they can figure it out (I've read elsewhere that it could be a throttle position sensor failure?). This might be an issue since there is a non-stock tune on there and other mods.
3. Take it for a dyno-tune somewhere?
4. Ask the brilliant folks on this board for suggestions before tossing buckets of money and time out of the window
 
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#2 ·
Daytona 675 cam intake cam?

Haven't heard of that one. Could you mean 955 cam?

There was someone that did the swap and did a write up on it.

Somewhere in this forum.http://www.triumphrat.net/showthread.php?t=733698

Anyway, has it always smelled like that, or did it just start doing it?

Best guess is you would need to get a custom map made. All a dealership could do is put it back to stock.
 
#5 ·
Thanks for the responses! Sorry, that was a mistake. It's a cam from a 955 daytona <sheepish grin>. Also my city mileage can be as low as 12-15 in traffic (with splitting).

As for tuning, I called a shop with great reviews who recommended power commander but I know most on this board use and prefer Tune ECU. I would prefer Tune ECU based on the reviews from this board and this thread:

http://www.triumphrat.net/sprint-forum/181624-tune-ecu-vs-power-commander.html

This remark from that thread made me think twice me though:

" Actually, there is very little practical difference between TuneECU and a Power Commander for most street-oriented tuning. However, as many have said, TuneECU does allow direct access to the ECU and you can do some things a PC doesn't support.

The big advantage of the PC is the time required to complete a street tune, which is a lengthy proposition anyway. Using a PC, the tune can be updated while the bike is running. Using TuneECU or Tuneboy, the engine has to be stopped and a new tune uploaded into the bike's ECU. Thus a comprehensive tune, which should be done at 10% throttle increments and different loads, will require number of engine stops and tune uploads, all of which count as dyno time. If the operator is quoting fixed-price for a tune, using the PC is quicker (hence cheaper) for him. For you, the extra dyno time probably costs less than a PC.

Personally, I used TuneECU on my Sprint and was quite satisfied even though the uploads were a little tedious. However, on my Ducati, which has a "kit" ECU, I used a PC to reduce the amount of dyno time required. But that was because I had the PC on the shelf! The net results, percentage improvements, etc. were similar on both bikes. The software is sufficiently similar that anybody who is competent with one can use the other without a significant learning curve. As always, YMMV."

Assuming I can't find a shop that's familiar with Tune ECU, is it better to have a great shop but worse software or better software but a shop not experienced with it? In other words, buy Tune ECU or PC5? I don't plan on doing any other engine mods; I just want to get the fueling right with my current setup. I'm willing to pay much more to maintain a smooth throttle though.
 
#6 ·
I never understood the cam swap; it seems to be something people do when they have too much time on their hands and want to make their triple more like a four banger. If I were you, I would just put factory cams back in, load up a factory tune, and take it from there.

Cheers,
-Kit
 
#7 ·
Thanks Kit. My dilemma is I think putting the cam back will be a lot more work than just fixing the tune AND I really love the bike as it is right now minus the exhaust stink. On the flip side valves are coming up anyway so it might be worth doing the swap while doing the valves.

The previous owner built an excellent bike that just needed some tuning I think. I only started caring now that I have the suspension and brakes fixed up.
 
#8 ·
I had not even considered Kit's idea. It's a great one - IMO the best. The cam only helps if you've done a ton of other mods and ride it like you stole it on a daily basis. Done alone with just airbox mods, the power you gain will be very near readline and way above- which we know the crank and rods can't handle those rotational speeds. The cam kills torque below those high rpms. And you don't know where that cam's lobe centers were set to - which actually could be much of your problem.

I actively searched for that cam (used, very specific years - 2002-2005 perhaps? ) for a couple of years and gave up - the demand is way too high! A new cam will run around $350US IIRC. It ended up being easier to just buy a liter bike to satisfy the horsepower cravings.
 
#9 ·
I honestly think it's extreme to have to revert back to stock cams and maps at this stage - it should be capable to get it dialed in.
Where in Bay Area are you incidentally? I'm in Pleasanton
I'd certainly be interested in looking at your map and comparing it to std map - perhaps you can post it here.
(you should be able to upload/attach map directly in post)

For dyno you have a couple of local shops that are intimate with TuneECU and Triumphs
JT&S at sonoma raceway or Factory Pro in San Rafael.

There are also couple of members here who have gone that route before and maps might be available from them for the asking
(@sussurf for example whom you might ask if he would share with you)

The last option would be to install your own WBO2 and do your own mapping (I have one on my bike)
 
#11 · (Edited)
I honestly think it's extreme to have to revert back to stock cams and maps at this stage - it should be capable to get it dialed in.
Where in Bay Area are you incidentally? I'm in Pleasanton
I'd certainly be interested in looking at your map and comparing it to std map - perhaps you can post it here.
(you should be able to upload/attach map directly in post)

For dyno you have a couple of local shops that are intimate with TuneECU and Triumphs
JT&S at sonoma raceway or Factory Pro in San Rafael.

There are also couple of members here who have gone that route before and maps might be available from them for the asking
sussurf for example whom you might ask if he would share with you)

The last option would be to install your own WBO2 and do your own mapping (I have one on my bike)

Thanks DEcosse! I'm in San Francisco. I've done amateur tuning an turbo cars before but never a motorcycle. Grabbed a cable off amazon for TuneECU to upload that map.

That's a good idea about the map from someone else. I think I was reading that sussurf has velocity stacks too which the shop is offering. I actually don't need more power anymore, I'm just looking for better fueling, but we'll see what he wants for those stacks I guess since I'm paying for the tune anyway.
 
#15 ·
Just to be clear, I think it would be easier and cheaper and save a lot of time to swap the factory cams back in. If money is no object and you don't care about low end and midrange, all it takes to tune it is time and money and I'm sure the shops DEcosse recommends can do the job.

Cheers,
-Kit
 
#16 ·
Sorry, sometimes tone doesn't come through very well on the internet. To be clear, I'm not attempting to be critical and really appreciate the great advice you've given me (as always on this board). I've gotten a few quotes from shops that seem fairly reasonable but my assumption is that after having the bike for a week the tune will be pretty close.

If that assumption is wrong then I could see how this would get expensive quickly.
 
#17 ·
No worries, man, I was just trying to clarify what I was saying precisely because tone doesn't come through on the 'net. :)

I'm guessing a reasonable quote from a shop is still a lot more than $100 for some eBay cams, but I'm very comfortable pulling my cams and I know some people are not, and there are many other variables involved here.

Cheers,
-Kit
 
#18 ·
A quick update and a little bit of egg on my face. Turns out my airbox was really clogged - that was insanely stupid not to check first. The bike is still a bit on the rich side I think but it's not nearly as bad as it was, which is to say it smelled like raw gas coming out of the tailpipe. The tuneboy came in this week so I'll try to post up my map anyway.

I'm still interested in a tune and will keep everyone posted with a list of mods, the map, etc if there's interest. One thing I might add in favor of the cam swap: I've gotten several compliments from people who ride/work on triumphs about the throttle response and ability of the engine to rev. I don't know if it's related to the cam but that's the only actual engine mod I know of other than airflow stuff. People describe it as a "crisp" or "quick" throttle so the previous is just my interpretation of what they're trying to say.
 
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