Author Topic: Swm not revving out?  (Read 5854 times)

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Offline hampster

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Swm not revving out?
« on: December 28, 2014, 05:23:16 PM »
Hi all,
 
My tf1 250 starts first kick idles fine , till mid throttle than seems to brakes down ? Sound like its electrical the ignition system has been re wound looks a bit average does any body know where I can get a new electric system?

Thanks chris

Offline Slakewell

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Re: Swm not revving out?
« Reply #1 on: December 28, 2014, 05:26:40 PM »
Why not PVL? or similar?

Have you tried it with no Muffler or air-filter? 
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mainline

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Re: Swm not revving out?
« Reply #2 on: December 28, 2014, 05:54:17 PM »
Try disconnecting the kill switch, may have a dodgy connection, not earthed properly etc
« Last Edit: December 28, 2014, 08:14:10 PM by mainline »

Offline bigk

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Re: Swm not revving out?
« Reply #3 on: December 28, 2014, 09:58:53 PM »
Don't discount carburetion, check needle & needle jet are not worn.
K

Offline shortshifter

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Re: Swm not revving out?
« Reply #4 on: January 02, 2015, 06:55:31 PM »
Hi Hamster.Seem to remember a rebuilt Husky with same problem,guy tried everything to fix it.Turned out it was the muffler restricting the engine ;)

Offline Bamford#69

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Re: Swm not revving out?
« Reply #5 on: January 02, 2015, 08:54:16 PM »
Hi,
have look at Fuel tank breather , and take fuel line off and check fuel line/tap flow,
cheers

Offline oldyzman

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Re: Swm not revving out?
« Reply #6 on: January 02, 2015, 09:08:19 PM »
Recently purchased a cr250 1989 "race ready" was also weak at high RPM. Changed the muffler and put back to std jetting was a bit rich. Goes really well now.
Once your bike is warmed up does it still blow heaps of smoke mid range?
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Offline supermotomc

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Re: Swm not revving out?
« Reply #7 on: January 04, 2015, 10:21:15 AM »
so what have you touched or did this just appear have you worked on this before you got the earth wire on this 12v to earth ok have you had the disc valve out??
« Last Edit: January 04, 2015, 10:25:29 AM by supermotomc »

Offline kim80y

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Re: Swm not revving out?
« Reply #8 on: January 04, 2015, 04:43:51 PM »
I had a similar problem for a long time, and it was the HT coil, there was a "bad batch" of aftermarket ones floating around, I had two of them before the importer fessed up........

Cheers
Kim ::)

Offline hampster

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Re: Swm not revving out?
« Reply #9 on: January 07, 2015, 09:39:59 AM »
Thanks All,

Have tried the following,
The bike is running a 34 mm Dellorto have put in standard new main jet , pilot jet , needle , needle and seat. No change.
Run the  bike with the petrol tank cap off seems to have plenty of fuel, no change.
Have taken off the muffler and run , no change.
Have taken out the air filter and run , did make it run worse ?
Have varied the timing,  advanced and retarded , backfired a bit when advanced?
Have tried a colder plug a 9, no change.
Still starts first kick and idle fine till mid-throttle?
The stator has been rewound and looks a bit dodgy?

Yet again any help would be much appreciated

Chris.
« Last Edit: January 07, 2015, 09:42:07 AM by hampster »

Offline Lozza

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Re: Swm not revving out?
« Reply #10 on: January 07, 2015, 11:00:35 PM »
VHSB or PHBE carby?  Can you tell me the main jet, needle, atomiser tube and I'll check the fuel curve
Jesus only loves two strokes

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Re: Swm not revving out?
« Reply #11 on: January 07, 2015, 11:49:46 PM »
Try disconnecting the kill switch, may have a dodgy connection, not earthed properly etc

Offline pokey

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Re: Swm not revving out?
« Reply #12 on: January 08, 2015, 12:12:25 AM »
Any chance of posting a pic of the plug?
to me it sounds like an air leak . specially seeing as allowing more air by removing the filter makes it run worse.

Offline Mick D

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Re: Swm not revving out?
« Reply #13 on: January 08, 2015, 12:42:56 PM »
Hi Chris, Mid throttle,
Fuel maybe??
Mid throttle = needle jet

Have you completely stripped the carb to make sure?
Removed the emulsion tube?
100% sure that the air draft passage from the bottom of the air horn to the emulsion tube is clear?

Worth verifying, good luck.
« Last Edit: January 08, 2015, 02:18:14 PM by Mick D »
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Offline Canam370

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Re: Swm not revving out?
« Reply #14 on: January 08, 2015, 04:15:30 PM »
I don't know if anyones asked but was the onset of the issue sudden or progressive? Sudden would point towards electrics (the Bosch CDI's weren't startling). The stators were generally OK. Multimeter checks won't always show up a fault. Send the lot off to be checked dynamically by a professional -  including the kill button -  it'll be cheaper than shotgun solutions to imagined repairs. Particularly if someones already monstered the electrics.
 Progressive deterioration leads down a whole different fault tree analysis.
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Offline GMC

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Re: Swm not revving out?
« Reply #15 on: January 09, 2015, 09:22:19 AM »
I don't know if anyones asked but was the onset of the issue sudden or progressive? Sudden would point towards electrics (the Bosch CDI's weren't startling). The stators were generally OK. Multimeter checks won't always show up a fault. Send the lot off to be checked dynamically by a professional -  including the kill button -  it'll be cheaper than shotgun solutions to imagined repairs. Particularly if someones already monstered the electrics.
 Progressive deterioration leads down a whole different fault tree analysis.

As Canam asks, did you buy it like this, did it behave this way after a rebuild or did it gradually/suddenly start behaving badly.

If your a bit suss about the electrics then send the whole kit and kaboodle off to someone that can run the whole package and test it. There are a few business's that offer this service.

Don't know much about the Rotax motors, is it possible the rotory disc is in the wrong position or that some one has trimmed it too much or maybe it's a Trials disc??
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Offline hampster

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Re: Swm not revving out?
« Reply #16 on: January 20, 2015, 09:11:36 PM »
Thanks all,

I brought the bike not going had a spun key way I was hopeing that this was the problem.

I Got a new piston and did the re bore also put in new crank seals.

I think the next thing to do is to get the electrics checked, does any body know who can do this?

Thanks again for all the help.

chris.
« Last Edit: January 20, 2015, 09:29:03 PM by hampster »

Offline foxy999

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Re: Swm not revving out?
« Reply #17 on: January 22, 2015, 03:32:27 PM »
get onto tatey chris, he sent a pvl away for me and got it sorted out.
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Offline Lozza

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Re: Swm not revving out?
« Reply #18 on: January 26, 2015, 07:11:21 PM »
The carby settings are complete shit.
Jesus only loves two strokes

Offline supermotomc

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Re: Swm not revving out?
« Reply #19 on: January 28, 2015, 01:40:11 PM »
disc valve is out of time

Offline hampster

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Re: Swm not revving out?
« Reply #20 on: February 21, 2015, 08:31:24 AM »
Thanks all,

Finally got the tf1 to rev out the following items changed.
Disc valve replaced with original swm it had a modified disc installed.
Crank seals replaced.
Replaced stator original one was tested and was braking down at higher revs .
Carby jeted correctly.
Just have to work on the carby a little ,the float height must be wrong as it seems to run out of fuel and works when the choke is on.

Thanks for all the advice especially Lozza a wealth of information.

Thanks Chris.

Offline NSR

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Re: Swm not revving out?
« Reply #21 on: February 21, 2015, 04:16:31 PM »
What about Me >:(  I was no help at all ;D  Can I have a ride? 
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Offline supermotomc

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Re: Swm not revving out?
« Reply #22 on: March 02, 2015, 03:30:08 PM »
yea right !

Offline Nitram

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Re: Swm not revving out?
« Reply #23 on: March 04, 2015, 11:12:02 PM »
Hamster, the TF1 looks just like a Can-Am Bombadier engine.  Not sure where you live, but find your local Can-Am enthusiast, and borrow their stator assembly- i.e the RHS crankcase cover with the ignition bolted inside it.
Let me know if you're in NSW and I can probably help.
Cheers,
Nitram

Offline supermotomc

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Re: Swm not revving out?
« Reply #24 on: March 05, 2015, 05:19:25 PM »
so you have multi pole ignition what have you done with the { is it the yellow and black wire}

Offline hampster

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Re: Swm not revving out?
« Reply #25 on: March 28, 2015, 06:29:23 PM »
Thanks all,

Finally got the tf1 to rev out the following items changed.
Disc valve replaced with original swm it had a modified disc installed.
Crank seals replaced.
Replaced stator original one was tested and was braking down at higher revs .
Carby jeted correctly.
Just have to work on the carby a little ,the float height must be wrong as it seems to run out of fuel and works when the choke is on.

Thanks for all the advice especially Lozza a wealth of information.

Hi all,
Well I have tried every thing to get the carb to run with out the choke,
It starts first kick runs fine and revs out for30 sec than runs out of fuel (sounds like)and when the choke is flipped back on runs fine again and revs ,have tried the following.
Doubled checked float height,lager fuel hose,checked fuel tap,removed tank cap,changed needle and seat for new,cleaned carby 16 times.
In conclusion I will be having a dellorto burning at the stroke of midnight .
Does any body know the mikuni carb set up for a swm tf1 250.

Thank chris.

Offline Sweep Rider

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Re: Swm not revving out?
« Reply #26 on: March 28, 2015, 09:36:17 PM »
Before you burn it can I buy all your jets off you... ;D ;D ;D
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Offline Canam370

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Re: Swm not revving out?
« Reply #27 on: March 28, 2015, 11:51:50 PM »
If you are using an inline fuel filter try removing it.
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Offline Lozza

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Re: Swm not revving out?
« Reply #28 on: March 29, 2015, 03:33:42 PM »
What size is the float valve?
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