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exploding speedmaster, please help!

6K views 29 replies 11 participants last post by  danb 
#1 ·
Hi guys,
I recently bought a blue '04 triumph speedmaster and it's been running like a beauty, give's you a thrill just sitting on it, but recently after cold mornings it'd be more difficult to get it started, and it's not being constantly holding its revs. I origonally thought a bit of red X would do the trick.

Occasionally the revs would just drop and it would start chugging along and backfiring, and it's become more and more of a common thing now. You can actually feel little explosions next to your leg where the air filter would be, and the heat coming off the engine and exhaust is unreal... you can actually see marks on the exhaust now from it...

I can't ride it anymore as it is randomly losing power,Does anyone have any suggestions what this might be? I'm thinking something to do with the air filter being clogged up? although a friend mentioned it could also be the spark plugs.

To be honest I'm fairly new at maintanance, this being my first > 125cc bike through direct access, but if anyones seen this kind of thing before or has any ideas what it could be it'd be much appreciated!!

Cheers! :cool:
 
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#2 ·
Wow, seems as though lately I have read much about this sort of problem: hard starting, backfiring, stalling - the common factor is they all seem to have been remedied through electrical fixes, as in pick up coil, ht coil, or ignition control unit. Easy to rule out fuel/carburetor problems through the usual checks so I'd do that. Then...
A guy I know who teaches auto technology says 95% of carburetor problems are electrical [a bit of a joke there].
 
#4 ·
I agree.

what mileage is on your bike and do you have it's service history?
 
#3 ·
Try doing a little standard maintenance first.

1) Replace the air filter - I would use a K&N
2) Replace the spark plugs - NGK Iridium are good; put some dielectric grease one the connection between the plug wire and the plug.
3) Oil and filter change - K&N also makes oil filters and you can choose between black or chrome - Mobile 1 and Motul are both excellent fully synthetic oils
4) Replace all your fuses - clean sockets with electrical contact cleaner and then put dielectric grease on each one.

Start with that and see how your bike runs, this is all cheap stuff and needs to be done anyway. Then if the problem persists we can try to narrow it down further.
 
#5 ·
The Speedmasters have a really dumb design for the piece of body trim that fits around key switch and in front of the fuse box; it's cup shaped at the bottom and collects water/condensation. This creates a steady high humidity condition around the fuses at all times, making it ripe for corrosion. My Sppedmaster stopped starting one day out of the blue, I found my fuse box was an awful mess. I drilled a hole in the bottom of mine to let any water drain out.
 
#6 ·
Hi all,

Thanks for taking the time to help me out. I haven't done much to it yet which is the reason for the late reply - I was waiting to do the maintenence with the help of a mate

Marc >
I've got some replacement spark plugs which I'll be fitting and checked the air filter which looks clean - with the exception of an oily rag that the previous owner had left almost covering the intake?! - which I've now removed...

I'm wondering if it could be due to the fuel mix, could an excess amount of Red-ex cause it not to combust properly? It said add half the bottle to a full tank, but with hindsight it was probably talking about a car tank rather than the peanut I've got on the speedy.

Bonza > Mileage is at almost 14k - I've been doing about 400 miles / week recently with my new job. Now I'm getting the train, and such nice weather this week too, typical!
 
#7 ·
It sounds like that oily rag could have been your problem, even a little obstruction can starve your engine of oxygen and cause unburned fuel to ignite sporadically.
 
#9 ·
I would go ahead and do all the maintenance items listed so far to rule that out - it needs to be done anyway.

How many kms/miles are on the bike? It might be due for a valve adjustment.

Are you using the choke when it's cold?
 
#10 ·
I agree with the others who have written in that you can go over your electrical stuff to eliminate those possibilities.
Something is giving me a strong feeling about a possible stuck exhaust valve though.
If none of the previous advice helps I would definitely pull the cam cover and rotate the engine (using the rear wheel in a high gear with the bike on a stand) and make sure the exhaust valves are opening properly. Its simple enough to do....

good luck
 
#11 · (Edited)
I was going to replace the spark plugs tonight but theyre in a right awkward position, would have to take the tank off to replace them with the tools I've got... have to grab some new ones tomorrow.

I managed to get it started fine tonight and it even rode very well for > 5/10 minutes (I was that confident it had just fixed itself - probably out of my own desparation!!) but then i realised it was only giving me about 50% accelleration... until it suddenly kicked in, but then it started chugging again a few mins later and the engine started getting a bit too hot for my liking.

Geimer:
It's done 14,000 miles appox, and the service history is looking good.
It sounds compicated but I'll give that a shot tomorrow, cheers!

EDIT: Also - I noticed some kind of adjustable valve/twisty knob (that's the mechanic in me talking.../) attatched to the engine - does this have a function?

P.S. anyone know any way to get rid of the bronzing effect on the pipes? It was a beauty once :)
I'm learning loads from this, and really enjoying it at the same time.
 
#12 ·
It's hard to get at the sparkplugs because of the air injection. The bike doesn't need the air injection (it's for emissions purposes) so most people remove it. You can get a AI removal kit from most Triumph dealers. The AI is also what's responsible for most of the pipe discoloration. Some have said that "Blue Away" works good on getting the discoloration out; that with the AI removal will probably change your pipes back and keep them that way.

Some people also consider the discolored pipes more of a feature than a failure.
 
#13 ·
Hey, does it run OK with the seat off?

I had a problem with a sticker on the underside of the seat. Tinkering in the shed, all seemed OK, put the seat on and ride, crap ??

The sticker was being sucked into the intake snorkel (which I tossed away) and effectively acting like a valve shutting off the air almost entirely.....

Sticker removed and all OK....who would have thought !
 
#16 ·
Hey Binnsy

I was almost sure you were on to something. I looked under the seat thismorning and there was the very same label flapping around, but not sure if it was long enough to cover the intake.
Cut it off and started 'er up, but still the same problem - good call though mate.

P.S. I'm in Newcastle, UK.

I've ordered a K&M air filter which should be getting here in a few days, and getting a spark plug tool tomorrow. If no joy with that I'll check all the electrics over this rainy weekend in the garage.

BoozeTrump> crankshaft sensor problem also looks possible, can you diagnose it yourself or is it a garage job?
 
#17 ·
Try checking these things also;
1. Check for Vacuum leaks. Make sure you check the vacuum plugs on the carbs. Also, check the intake rubbers for cracks espcially around the clamps. Cracks might not be evident so check closely. Check the intake clamps on the carbs if they are tight also.
2. Do you have fuel going to the carbs? Open the drain cocks under the carbs after you attach a hose to them. Drain them into a jar. Do you have a steady stream of fuel pouring out? If not, the hidden fuel filter between the carbs might be plugged.
3. Have you tried cracking the tank when the bike looses power? Sometimes the fuel tank vent gets plugged with debris at the outlet just behind the engine on the left side or the tip over valve situated on the vent line just between the carbs sticks or the vent line gets pinched just under the fuel tank. The check is to loosen your fuel cap to see if things run better. I don't think this one is the problem though since this usually only happens when you have ridden for a little while.

Have you pulled your plugs yet. What colour are they and what condition are they in? White - too lean. Black - too rich.
 
#18 ·
Update:

I replaced the sparks and the air filter with a K&N and took it for a ride...

It was all looking good until it had warmed up and at low rpm's it still popped a little / lost power occasionally. I thought I'd keep it going and keep the revs up to see if it improved and all was good for about 10 miles - so happy with it - until I realised that the throttle had stuck....

I was doing about 60mph in 5th and could hear the engine screaming, but letting go on the throttle did nothing - it was basically riding itself. The only thing I could do was pull the clutch in and hit the kill switch - scary stuff.

I managed to get it stopped but noticed that the clutch has to be let out way further than its ever been to get the bike moving... at this point I thought best leave it at the local train station - it didn't feel safe to ride.

I don't know if this is a seperate issue or part of the same problem, but I've decided to book it in for a full service/repair at my local garage in a weeks time, will just have to get the train into work until then. Going away on a short tour in a few weeks though, so this is hardly ideal timing :) but at least it'll be looked over before I go ....Just hoping the engine hasn't been damaged.

Still interested in finding out what's going wrong with it and looking at it myself, but at least I've got someone to look at it if it's beyond my ability to fix.

P.S. I only bought this bike about 2 months ago - does the dealership have any responsibilities for the condition of the bike?

Cheers
 
#21 ·
I don't know if this is a seperate issue or part of the same problem, but I've decided to book it in for a full service/repair at my local garage in a weeks time, will just have to get the train into work until then. Going away on a short tour in a few weeks though, so this is hardly ideal timing :) but at least it'll be looked over before I go ....Just hoping the engine hasn't been damaged.

Cheers
If your bike was bought new, it will be under warranty and Triumph should fix it.... if it was used, I don't know what the UK laws are about used bikes.

All the new bonnies have a rev-limiter built in to the ignition control system, even the carb bikes, people bump into the rev limiter when riding hard. Some people plunk down money for a CDI unit that allows them to run the engine another 1,000 rpm before the limiter kicks in, so I would be shocked and amazed if the stuck throttle caused any damage at all.

The twins rev pretty darn high before they hit the limiter and if it isn't intentional, they sound like banshees but won't harm the engine.

Good luck with all of this and let us know what shakes out.
 
#23 · (Edited)
Well...

I had to try and ride the bike back tonight because I couldn't leave it in the slightly dodgey area I parked it in (although I think the insurance claim would get me a nice brand new bike hehe) It started up fine, and got all the way home only it was quite a bit louder than it normally is (have noticed that since changing the filter - weird) but also a regular clicking sound coming from the engine.

By the time I got it home (8-9 miles) it was still running but was very hot, smelled a little funny (my imagination?) and was popping just a little but still rideable.

Carbs definatly sound like the next thing I'll be checking, and getting a new clutch cable. Cheers again for all the advice, I'll keep this updated - I'll be an amature mechanic in no time :)
 
#24 ·
Update:
(My speedy is now trashed!!)

http://www.triumphrat.net/triumph-m...g-screwed-over-by-dealership.html#post1341385

I guess I'm going to need a new engine, I've been quoted £900 by the dealership I origonally bought the bike from - does that sound right or over inflated?

P.s. feel free to tell me if you think I might be out of line with my comments to the dealership - I just feel they've sold me a duff bike
 
#26 ·
We're talking a second hand engine here with about 11k miles on the clock :eek: - although theres no way to verify the mileage or whether it's been abused.

I pushed them on the phone and told them I (might) be willing to pay for half the cost of a replacement engine but I think they might have just doubled the price, not easy to find a comparison price on the net though after a few hours googling.
 
#27 ·
I am sorry I did not read the replies carefully so I may miss some. Before going crazy ......... Have you covered the basics first:

1. What the condition or the original spark plugs, any signs of too hot or too rich in fuel?
2. Have you done an engine compression test?
3. Rule out the fuel supply issue from Tank to carb
4. Bad gas
5. Check oil for proper consistency and overfilling.

Good luck.
 
#29 ·
I had a similar problem with my 07 America, bucking, stalling, backfiring in a very random manner. I WAS convinced it was a fuel problem. What I found was the positive battery terminal was very loose and occassionally arching!!! A 2 minute fix and I've been good ever since...it seems the electrical connections on there bikes are a weak link.
 
#30 ·
Ah cool tip, thanks
How would I go about fixing it - screwing it in tighter?
(before laughing out loud - I'm a bit of a mechanical novice :))

Marc:
Cheers for that, sounds like it might have been bumped up a bit but I'll make sure to ask for a receipt.
 
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