OzVMX Forum
Clubroom => Tech Talk => Topic started by: Alisdair on February 22, 2014, 08:21:03 pm
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Hi all
I am extremely desperate at the moment, I know it isn't VMX and I will take down the post if required.
A few months back I bought two TT600R's (98/99) with the intention to make one good bike out of the two.
One was bought from action as a stat write off, it was stolen and recovered. Missing the rims, CDI and the wiring was in a mess. Suspension and motor were mint though.
(https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-prn2/t1/1779069_230970950422893_219141009_n.jpg)
The other was bought cheap off Gumtree from the Gold Coast, it was meant to be sold as a runner, however, the owner couldn't start it in front of me.
Didn't worry me, I got it cheaper as I was mainly after the frame. Took it home, started the first kick for some strange reason. Motor was smokey, rattly, broken mounts, just a flogged out bike.
(https://scontent-b-pao.xx.fbcdn.net/hphotos-ash4/l/t31/q77/s720x720/1097722_170085306511458_55480379_o.jpg)
The bike had an intermittent spark, it would either start first kick, or not at all. So my father and I cleaned and checked every single connection on the bike, and tested every component we could. It appeared that the CDI was buggered, so I bought a CDI from a place in Belgium since Yamaha wanted over $1200 for a replacement(HPI ignitions) This appeared to cure the no spark problem, the bike would start, however it would give a major kickback. Overall we were happy with the aftermarket CDI, so we decided to try to get Auction bike running.
Swapped the rims, and the carbs (Carbs in the Auction bike were full of gunk). Chucked in the CDI, and there was no spark, the wiring harness was pulled to bits from whoever stole the bike, so we swapped the wiring harness. There was still no spark, after a bunch of stuffing around, it finally got spark again. However, it was almost impossible to start due to the kick back.( Getting just over TDC and jumping the bloody thing).
When the bike was started, it ran really well, pulled through all the gears, lifting the front with ease.
Started to swap coils/stators/pickup/ everything, and no difference was made to the bike. After a few weeks of messing around, we eventually lost spark again. After a few weeks of not getting anywhere, we went to a local bike mechanic, explained our situation and he suggested a really well known Auto-Electrician workshop. They took the bike in, after a few days I got a call back saying they fixed it and were starting it daily, saying it must of had connection somewhere. Took the bike home, and it would not start at all. Rang them up the next day and they told us to take it back in. Supposedly the spark plug had fouled on it.
After this the bike started/rode amazingly for a few weeks, Started first kick every kick, and I rode it for a few hours everyday around the yard(I was on University break)However, after a few weeks had passed, it was back to the kick back issue. Impossible to start by kicking, we tried clutch starting the bike. This was next to impossible due to the compression it has.
Today resorted to tow starting it. Pic bellow to explain the set up. Pipe over the axle
(https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-ash3/t1/1926719_230970070422981_2116287599_n.jpg)
Took it around the back yard, would just lock up in every gear and tear the grass up, turned over a few times, but not enough to justify the damage to the yard. Took it on the driveway and it would just lock up going down the dirt driveway, so we took it onto the road (Private bitumen road) , after some serious backfires/kickback sounds it started. Ran really well, let it run for a while to warm up. We then decided to use to original CDI again. We got the bike started going down the driveway, and it didn't appear to backfire/kickback as much.
So we then tried to get a timing light on it, and the timing light we have, we couldn't get to work. Not 100% sure why either. Turned the bike off, and started it twice first kick! Tried for a third and got major kickback. Swapped the aftermarket CDI and just got instant kickback. Swapped the CDI's back and forward for a while and we are just getting kickback.
Sorry for the long post, I am really desperate for help at the moment.
Any help would be greatly appreciated.
Alisdair
Brisbane area
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Makes it a bit harder with all the swapping of parts at once, to rule out one part.
When it kicks back are you giving it a little throttle , that can cause that , no throttle on start up, and is the idle sett close.
or could be a elect prob . good luck
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Kickback is usually caused by too much advance on the ignition. For ease of starting 4 strokes have a retard/advance set on the ignition. If the cdi unit is no good this could be the cause of the kickback and intermittent spark. You really need to check were the timing is with your timing light.
My TT500 has about 5' static advance and my 650 Yamy has 12' static.
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Thanks heaps for the replies
I didn't swap all the parts at once, swapped them one at a time, literally tired every single combination.
No throttle at all, I have a IT465, and I learnt pretty quick that throttle can cause come brutal kickback.
I think the timing light might be the best start, will definitely have another crack using it within the next couple of weeks.
It's just strange, as the bike was running perfect for a few weeks, then it went back to kicking back :/
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Check the inlet valve clearance as this can confuse issues. I have come across this twice before oddly enough with Yamaha stators that they do this erratic working fine then stop and then work fine again.
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sorry i dont have any advice on the TT , im a two stroke tragic , but your towing method , wow, now i know how to move my bike when i dont have a trailer, thanks
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I had a friend come over today who had a TT600r
I tested the aftermarket CDI's on his bike, and it wouldn't start up. It was making a weird noise through the carburetor, kinda like a small backfire.
Tried the original CDI and the bike fired right up.
I got the CDI units from HPI ignitions in Belgium, I have sent them an email and hopefully they will help me out.
Thanks to all for the replies,
I will make any update as required.
Cheers
Alisdair
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timing light is your best option, just remove spark plug and kick over to get the base setting.sounds to advanced on low rpm.
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sorry i dont have any advice on the TT , im a two stroke tragic , but your towing method , wow, now i know how to move my bike when i dont have a trailer, thanks
I used to tow my first dirt bike 500 A jay like that to Moorebank Vineyards etc behind my 36 Ford till I say another A jay with a snapped lower leg from towing like that so it was trailer time!
Cheers pancho.
P.s I would go bacto basics with 600, flywheel position (loose and sheared key, ) timing chain loose out stuffed loose camshaft bearings, loose came sprocket on camshaft etc, then back to electronics
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Please excuse my bad typing as I'm trying to get used too these tablet thing!
Pancho
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I have a video of the bike running with the original CDI unit.
http://www.youtube.com/watch?v=w2_spZdeLNI
It appears that the bike is breaking down, revving out too early.I know it isn't a high revving bike, however I had a XT600 that would rev harder then this,
With this CDI unit in the bike, it appears to have a weak spark (I can hold onto it while someone boots it and it doesn't hurt much)
It randomly starts with it, eg, Will start first kick, then nothing. Other times, it takes heaps of kicks, then it randomly backfires (Due to flooding I guess) Then starts the next kick.
Thinking it is CDI related, as the aftermarket ones did not work in another TT600r and was doing the exact same thing.
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I had the same sort of problem with a tt600 after spending a lot of time looking at the cdi I found that the vacuum side of the carb was sometimes sticking open and sometimes wasn't opening at all :(
Just a thought. Darcy
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Did you get this sorted? Like Pancho said check to see if the keyway has sheared on the flywheel. I had a similar problem to this on an IT490 caused by a sheared key. If it doesn't rev that can be from a faulty pick up coil.
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Off Topic, I love yr Youtube stuff Al.
For anyone who wants to relive there crazy L & P plate days have a look a Al and his mate Chris's Youtube channel.
I stumbled across them one day and they cracked me up, it was like when I was 16 and running around with my mate, riding anywhere & everywhere having the best time.
I wish we could have documented our times, but even 8mm video camera was hard work back in the 70's.
http://www.youtube.com/user/YourPalsChrisAndAl/videos
On Topic did u try his CDI on your bike?? rather than yr cdi on his. or were u scared that u might stuff his?
Cheers
Wombat
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yes i was thinking check the flywheel key & if you pull the flywheel off to be 'sure to be sure', then do it up bloody tight. But another thing that happened a lifetime go on a re-wound stator charge coil on something [think early TT250] the red wire and brown wire were reversed at the coil, jeez that caused some headaches & think it was a similar kick back situation & erratic running. Long ago but was something along those lines. Not sure on the TT600 but [as someone said] pulser coil issues & if they have a white with green tracer plus white with red tracer, could the get swapped around [& what then happens], or pulser with way to much resistance causing spark to happen sooner[not sure if that can happen]. Remember an XR500 single shocker that broke two kick start shafts caused by a faulty trigger coil & kicking back real bad. Thanks.
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i ad a tt600l [what a lemon] but they do have a low/high speed pick up on them that sometimes causes trouble, you could check the pick up to rotor air gap using plasterseen, as others have said check the flywheel key for being sheered or just take the whole system off and send it to steve at better bikes in adelaide to test on his test bench. as to your after market cdi it sounds like theres something wrong with the advance curved they have programmed into it if its kicking back sooo bad on your mates easy starting bike. good luck with it and let us all know the outcome when its sorted. the tt/xt600's base timing is non adjustable as well
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Def check that flywheel key. Valve clearance ok? Remove the ignition coil and clean its mount to earth and clean the wiring earth connection with sand paper. Maybe disconect the kill switches from the wiring harness to try it. Check the plug cap conection where it screws into to the ht wire, usually a good idea to trim about 10mm off ond re-seat it . Close the gap up on the spark plug a bit (is it a new plug?). If you do these one at a time you can at least discount any of them at no cost.
Also backfire can be from a lean fuel issue. Carbies clean?
Kickback sounds like a spark problem