drops a cylinder

[Twinpotter]

Bluefox

I understand that the front lobes should point up/away from each other.

He notes this here (his fourth entry)
http://www.vtr1000.org/phpBB2/viewtopic.php?t=8326
"The cam lobes should also be facing away from each other:!:"

If this is not the case (wait for Sirch to confirm, I guess), then I know where I have gone wrong!

[sirch345]

That's spooky

I thought I'd just answered that question
http://www.vtr1000.org/phpBB2/viewtopic ... c&start=15

You are correct, the cam shaft lobes on the front cylinder should be facing away from each other if the valve timing is set up correctly, for removing the CCT using the timing marks

Chris.

[Bluefox]

just finished checking it out,nice one sirch,can't thank you enough,front bank out,stitch it all back together tomorrow night with refreshed vigour.
Thanks again

[tony.mon]

Tell you what, though, doesn't it sound crisp when you DO get the timing 180 out?

I was proper impressed, got right out there thinking this is good, sounds real bark-y and I'm in for a goodun here, seriously disappointed when it misfired all over the place......

if I could get the sound AND the power at the same time, now that would be worth having.

Anyway, the new Yam has Big Bang crank configuration, if they can make it work why not?
After all, as has been mentioned, it's just two singles on a common crank so there shouldn't be any reason it won't run smoothly.

So is it the coils not charging quick enough?

The plugs firing too close together and so not having enough downtime?

Some problem in the airbox with a cylinder's -worth of air being sucked out and not enough time to refill?

Any ideas, O talented ones?

[Bluefox]

Got it running this afternoon,perfect.

What i think fecked it up for me was when i stripped it about 3 odd years ago,after the head came off it was obviously lobes in when set up & stripped,when refitting about 12 months after i followed the pics in haynes manual & there the sh1t started.
Thanks lads.

[sirch345]

Got it running this afternoon,perfect.

What i think fecked it up for me was when i stripped it about 3 odd years ago,after the head came off it was obviously lobes in when set up & stripped,when refitting about 12 months after i followed the pics in haynes manual & there the sh1t started.
Thanks lads.

I'm pleased too hear you had a good result

Chris.

So is it the coils not charging quick enough?

The plugs firing too close together and so not having enough downtime?

Some problem in the airbox with a cylinder's -worth of air being sucked out and not enough time to refill?

Any ideas, O talented ones?

Some good thoughts there for sure. I'm not sure exactly what it is that causes it to misfire but I'd be interested to know

Chris.

[headgear]

Bluefox, quite a saga you have there and indeed I share the same symptoms with you with the exception that mine splutters at two/three k.

I had the missfire the same as you, I also changed plugs checked coils etc,
I also thought that the ecu had failed so bought one, still the same problem, I traced my fault to the throttle position sensor, I do not know what it does but I unplugged it and wahay no missfire.

P.S if you need an ecu guess who has got one for sale?

[Twinpotter]

The saga is over. Got it going!

Pete, you guessed right. The front Coil primary showed just a wee bit more resistance than spec (only about 3kΩ over) although I didn't see it as critical but a replacement coil did the trick. All this grief started with my seeking to check the spark at the plug! I suggest that the lesson here is to NOT start a storm with the plug cap off/not grounded (Doh!). I suspect that doing so likely fried/overloaded (via feedback?) not the ICU (although I now have a spare just in case) but the coil. Odd perhaps but that's how it panned out.

That said, it's been almost two months since I rode her and I've almost forgotten how she sounded! A spin up from the A1 from Stirling Corner to the "Schumacher esses" (the Borehamwood turn off - I wasn't about to go any distance right off) was a delight indeed. All just in time to go with my pal (who passed his test last week) to pick up his R6 but sadly just before the clocks change. Hey ho.

Thanks to all for the ideas chaps - appreciated!

Bob

PS. You may now extract the proverbial for my goof.

[Stratman]

I've almost forgotten how she sounded!

Gets me every time

Went out last weekend and was riding as much for the soundtrack as much as anything else

[Pete.L]

Nice one Bob!
Glad you finally got it resolved
Thanks for the feed back. That's another fault we can add to the "Check" list.

Pete.l

[Twinpotter]

Stratman
I'm a "Precision" man myself; I'm just getting to know her, after all. Nice solo though. We just need a self-centred warbler and a mullered tub thumper to hit the road!

[vtr9999]

well i had a cylinder dropping too, i changed every electrical part and even did front rings for 5lbs difference in compression, cylinder still dropped, it turned out that the carbs just needed to be balanced, a very simple thing to do i picked up gauges for 50bucks on ebay, it will also improve your throttle response, further more i fitted a electric fuel pump which eliminates almost all backfires when u come off the throttle a common thing with vtr's,

[bucklandswifty]

Hi All - I too would like to know if the cam lobes should point towards each other as on the rear? I am fairly sure when I set my manual ccts following the advice here they were not pointing towards each other. I did follow the instructions to the letter. If I have the 180 problem would this be revealed by the cam lobes?

Cheers - Chris

[sirch345]

Hi All - I too would like to know if the cam lobes should point towards each other as on the rear? I am fairly sure when I set my manual ccts following the advice here they were not pointing towards each other. I did follow the instructions to the letter. If I have the 180 problem would this be revealed by the cam lobes?

Cheers - Chris

Hi Chris,

The front cylinder cam lobes should be facing away from each other. All the info you need is in this link below (the 11th post down I cover the front cylinder). You are right in thinking if they were facing the wrong way the timing would be 180 degrees out. If it is wrong you will notice the engine bogging down around 5,000 to 6,000rpms.

http://www.vtr1000.org/phpBB3/viewtopic.php?f=31&t=8326

HTH's

Chris.

[bucklandswifty]

Hi Chris – Thanks for the information, I am 99% certain that my valve timing is correct having fitted manual cct’s. I did take the front cam cover off to make absolutely sure the marks on the cam sprockets were aligned with the head correctly and remembered them paointing away from each other and thinking "that's qeer!". I adjusted the tensioners so there is 8mm movement at the center of the cam chain between sprockets. I went to the trouble of having the front cam cover off having over tightened the cct’s by hand WAY too much, not in a gorilla way but when the engine was hot it would not start, just came to firing point and stopped. Having adjusted the things correctly I have a constant misfire on the front pot and the plug is black. I have had the carbs off and cleaned thoroughly ( my brother supervised, his sons used to ride F1 sidecar SFB Racing ) and Clive was head mechanic, so carbs aokay. The only thing I cannot say for sure is if the choke needle jobbie is seating properly, not without x-ray facilities. The choke action is smooth and seems to work as it should though. I am going to fit stick coils when they arrive, at least it will isolate dodgy coils. As I understand it, the ICU has individual wires to the coils but is in fact a wasted spark, so misfire on one pot is unlikely to be ICU related??? The bike is going to visit Ricky at Front Row Motorcycles this weekend, that will teach it\me a lesson! Cheers - Chris