Splutters, bogs, back fires & farts out the carb

[MacV2]

''The thing I am dreading is having to purchase a cdi unit for elimination purposes, best part of £100..''

If it's Storm one Frank has a spare CDI...If you want to try it to eliminate the issue he'll send it to you for fly tokens to cover the postage. If prob not cured send it back, if good buy it for £35.

CSML want 700 euros for one & it's out of stock !

[Varastorm]

Have you checked the connectors between cdi and coil?

Not too sure which connectors you mean Stephan. The only wires that I have played with are the ones that connect directly to the coils themselves & that was only when I swapped the coils over front to rear.

If it's Storm one Frank has a spare CDI...If you want to try it to eliminate the issue he'll send it to you for fly tokens to cover the postage. If prob not cured send it back, if good buy it for £35.

Cheers for the offer Mac, really appreciate it but the VTR cdi is different to the Varadero's single box & their not interchangeable. Otherwise I would of been more than happy to take you up on the offer

Latest on the search for the problem is a compression test.

I removed the plugs & connected the compression tester to the cylinders, front first, then rear.

I never applied oil or any spray lube into the cylinders to aid sealing. For both tests I held the throttle wide open & hit the starter for around 5 seconds each.

Front.



Rear.



Thank god it looks okay, well to me anyway

I was worried I had burnt out an exhaust valve due to my lean low-midrange home made filed needles

Looks as if it could be electrical & I'm not too good with electrics

As usual, any advice, help or Tips really appreciated guys

[Wicky]

If it's not a massive air leak in the intake / exhaust stystem then yes the £80 cdi on ebay would be worth a shot to see if that makes a difference.

[KermitLeFrog]

The only thing you haven't changed over is the HT leads. They don't (always) last forever.

[VTRDark]

Your just showing off now with your Snap on compression tester Yeh HT lead is good to rule out and cheaper than a CDI Run through all the electrical connectors methodically including the one that connects to the CDI. Very strange how it's suddenly started behaving like this though. As mentioned earlier double check the vacuum hole on the rear cylinder is capped off still. This has to be something really silly. It's always the silly things that get overlooked and hardest to track down at times.

[Stephan]

I agree it seems like electrical problem. Coils should be ok per your test, so there is cdi and wires left. That is why I wrote it. I would check every place conenected in the way between cdi and coil. Not sure how many connections are there, maybe only two. Check for corrossion or sings of burnt. ...

[tony.mon]

As you're still running carbs, you could check to see if it's the cdu by borrowing a Storm loom adn the two boxes- it should work for al of the ignition side without any modifications. You don't have to fit the loom, just cable tie it along the side of the bike to test it.

[Varastorm]

If it's not a massive air leak in the intake / exhaust stystem then yes the £80 cdi on ebay would be worth a shot to see if that makes a difference.

There's not a lot for me to look for Wicky. I've only got the carb boots & carb balance 6mm holes which are connected up to balance the new carbs I fitted.

The only thing you haven't changed over is the HT leads. They don't (always) last forever.

I'm looking into buying a 1 metre length of HT lead, nothing simple though http://www.pistonheads.com/gassing/topic.asp?t=1436844

Your just showing off now with your Snap on compression tester Yeh HT lead is good to rule out and cheaper than a CDI Run through all the electrical connectors methodically including the one that connects to the CDI. Very strange how it's suddenly started behaving like this though. As mentioned earlier double check the vacuum hole on the rear cylinder is capped off still. This has to be something really silly. It's always the silly things that get overlooked and hardest to track down at times.

It's not my compression tester Carl, it's a mates. Nice piece of kit though & cost ££££ I'm sure.

I've checked (unplugged & looked for anything odd/corrosion) the cdi connector & all the other connections I can see/find. I also checked the pulse coil & that read ok also, 108 ohm's. All looks good tbh.

Another issue I've come across whilst looking for cdi units is that there are two different cdi types for the carbed Varadero. 1 for 1999-2002 & 1 from 2002-2003 then its all change for the fuel injection models

At the moment I have a Phillips screw driver in the rear vacuum pipe. But I'll check around the base of the take off in the daylight tomorrow

I agree it seems like electrical problem. Coils should be ok per your test, so there is cdi and wires left. That is why I wrote it. I would check every place conenected in the way between cdi and coil. Not sure how many connections are there, maybe only two. Check for corrossion or sings of burnt. ...

I've had a good look through the connectors Stephan, nothing obvious & look good/like new tbh. I avoid the rain if I can & it lives inside.

As you're still running carbs, you could check to see if it's the cdu by borrowing a Storm loom adn the two boxes- it should work for al of the ignition side without any modifications. You don't have to fit the loom, just cable tie it along the side of the bike to test it.

I was thinking along the same lines Tony, but I'm going to need a lot more things to do the conversion/check. I'd imagine I'd need clocks, loom, ignition box & cdi. I'm not going to totally rule it out tbh, but I'll just plod on at the moment.

Mega thanks for all the advice guys. I really really appreciate all the help.

Any more ideas please fire away

[Varastorm]

One more thing, whilst I was checking the spark on the rear cylinder.

I removed the rear ht lead & plugged in the spare plug & held it onto the cam cover.

What I noticed was that the spark was not firing as slow as an idling v twin should in my book.

It seemed to be firing way too fast, as in practically constant flash, flash, flash.

I think I have read that the plug fires at the bottom of the stroke also, but has anyone looked or seen the spark from the rear coil.

If they have, does it resemble the description above?

Thanks in advance

[sirch345]

If it's like the Storm you have a wasted spark, it still fires at TDC but on every stroke, and being a four stroke you're only on the compression stroke every other stroke.

I haven't read everything written admittedly, but have you tried swapping the plug caps, or even cutting 1/2 an inch off the HT leads that goes into the plug caps, sometimes those HT ends can cause an electrical resistance,

Chris.

[Varastorm]

If it's like the Storm you have a wasted spark, it still fires at TDC but on every stroke, and being a four stroke you're only on the compression stroke every other stroke.

I haven't read everything written admittedly, but have you tried swapping the plug caps, or even cutting 1/2 an inch off the HT leads that goes into the plug caps, sometimes those HT ends can cause an electrical resistance,

Chris.

Good plan Chris, I've been reading a lot about HT leads & even looking into the cbr coil mod.

Really running low on new ideas now.

Quite sad to see it in bits after a whole week of fault finding.

Plan for tomorrow is pop to see my mates at the Anglesey track (Track day tomorrow anyone going) then in the afternoon do what you recommend.

I'll put the new plugs in & try it. Then if still the same unscrew & swap the plug caps, front to rear. If its still the same cut the ends off the leads & try again. Then if it's still the same pop to the fridge for a can of Carling

I am reluctant to do too many changes at once Because I really want to find out the problem & learn.

What I will add, it seems to run okay for a minute or two when cold (first start on the day) but as it warms 2-3 minutes, it starts to miss & spit

Really appreciate the help, thanks & if anyone has any other ideas, please fire away

[Varastorm]

Right then, Been to the track this morning as planned. It was blowing a gale, damp & spitting rain. I was back for 12ish, then started on the bike again

Firstly, I replaced the plugs with the newly arrived DPR9EIX-9, topped up the fuel funnel & hit the starter.

It ran spot on

https://www.youtube.com/watch?v=0jtD-8J ... e=youtu.be

The youtube link will not work by removing the "s" from "https". looks as if it's not my week.....

[youtube][/youtube]

Really appreciate all the help & advice from everyone.

I did change the plug over to spare I had on the bike but it just goes to show, you can't trust fack all

I really did think it was fuel with there being a definite difference at exactly 3000rpm & with it happening over a short period of time/miles I was sure it was crap in the fuel.

Oh well every day is a school day & big thanks again guys

Please feel free to take the pi$$

[john306]

Glad its sorted, you can relax for the weekend now and chill

[fabiostar]

happy days, nice to see the big girls sorted

[Varastorm]

Glad its sorted, you can relax for the weekend now and chill

Cheers John & Fabio, beer free weekend ahoy.

I drank too much during the week trying to come to terms with wrecking my pride'n joy

I'm so made up matey's, you wouldn't believe. Cheers again everyone