Jet recommendations / carb work

[fabiostar]

Those plugs have been runing pretty rich from the look of them.

[LewisB]

Those plugs have been runing pretty rich from the look of them.

Cheers Fabio.

I sprayed some carb cleaner around the carb boots while it was running and I have a leak! New boots ordered, when it comes to fitting them I’ll have a look at the new spark plugs which should identify any problems with my new mixture settings at idle (I’ve only been idling the bike since fitting them)

Here’s the old front carb boot. Apart from this damage from the carbs coming on and off they both looked okay, but tightening the jubilee clips made no difference to the vac leak!

[popkat]

Back to the popping, is you pair system blanked off ? If not the bike will pop and bang when cans are fitted.
The Quill cans also don't need rejetting unless someone has tried to modify then.



.

[popkat]

Here’s the old plugs, looks like they had life left in them but I had a new set. Left is the front, right rear

With modern fuel you can't read a plug like you used to so looking at them like that is of no good, although the electrodes don't seem to show damage,
To read plugs now you would have to look deep down in the porcelain for a grey ring, you need to cut the plug in half to see that so new plugs would be needed regardless.




.

[LewisB]

Here’s the old plugs, looks like they had life left in them but I had a new set. Left is the front, right rear

With modern fuel you can't read a plug like you used to so looking at them like that is of no good, although the electrodes don't seem to show damage,
To read plugs now you would have to look deep down in the porcelain for a grey ring, you need to cut the plug in half to see that so new plugs would be needed regardless.




.

Ah I did not know that! All i was going off was the generic photo guide for lean/rich plugs on Google!

I did the pair delete yesterday! Starting the bike up briefly this morning and it was a lot tamer! Didn’t pop once so im guessing it has helped but I won’t know for sure till I get out for a ride next.

Im still not confident I’ve got the pilot mix correct yet. Using the choke only increased the revs by about 500rpm It’s currently;
Front 2 1/2
Rear 2& 1/4 turns out.

I’ll give the choke cable another look as I may have just routed it wrong!

[Azer]

With modern fuel you can't read a plug like you used to so looking at them like that is of no good, although the electrodes don't seem to show damage,
To read plugs now you would have to look deep down in the porcelain for a grey ring, you need to cut the plug in half to see that so new plugs would be needed regardless.




.

Do you have a source for this?
I'm very interested to know more.

[LewisB]

Update!

After a new set of carb boots, PAIR delete and a little play with the mixture screws, she’s running a lot smother! Still a little uneven at idle still, but nowhere near as bad as before and the stumbling/misfires/backfires have completely gone. I will balance the carbs again next week. I have only had her running in the garden so will need to wait for some sunshine to confirm the good news! Fingers crossed though!

[sirch345]

Update!

After a new set of carb boots, PAIR delete and a little play with the mixture screws, she’s running a lot smother! Still a little uneven at idle still, but nowhere near as bad as before and the stumbling/misfires/backfires have completely gone. I will balance the carbs again next week. I have only had her running in the garden so will need to wait for some sunshine to confirm the good news! Fingers crossed though!

That's good news
It sounds like you are getting there. Yes, fingers crossed all is good out on the road

Out of interest, where did you purchase your new carb boots from?

Chris.

[LewisB]

Getting there indeed! Although I I didn’t think I’d have to sort all this out on a bike that was sold as running perfectly, I do love working on bikes and I’m always learning a lot so I’m not complaining!
I got the carb boots on EBay, £33 for the pair

[fabiostar]

Getting there indeed! Although I I didn’t think I’d have to sort all this out on a bike that was sold as running perfectly, I do love working on bikes and I’m always learning a lot so I’m not complaining!
I got the carb boots on EBay, £33 for the pair

just a we note. you have the front pilot screw and rear the wrong way round. . my old crusty memory says you want the rear one slightly richer then the front, no big deal running wise but the rear runs a tad hotter.

[LewisB]

Getting there indeed! Although I I didn’t think I’d have to sort all this out on a bike that was sold as running perfectly, I do love working on bikes and I’m always learning a lot so I’m not complaining!
I got the carb boots on EBay, £33 for the pair

just a we note. you have the front pilot screw and rear the wrong way round. . my old crusty memory says you want the rear one slightly richer then the front, no big deal running wise but the rear runs a tad hotter.

Thanks Fabio!
I didn’t even notice haha, I reseated the screws and they are now Front 2 1/2, Rear 3 1/4. Like I said still not perfect but it’s a lot better than it was, i still need to play with them as the revs hang abit when coming off the throttle and settling to idle which I think means lean? I just couldn’t figure out what cylinder needs tweaking and I ran out of time on it today so I’ll have another go next week.

[Donut 77]

This is a fascinating thread. I am about to delve into the world of carbs as a complete novice and all info is good. I’m frantically writing notes to help with what seems to be a bit of dark art. Is there a good thread for general description of how the carbs work on here? Eg very basic like what the different jets are, what the function of the slides etc?

[LewisB]

I’m glad to say the bike it running amazingly now! 95% of the popping on decel is gone, 99% of the clunking is gone (it made 1 clunk noise on an hour ride) idles great now, and low rpm riding is actually pleasant! Thank you everyone for your tips and support, couldn’t have done it without you! Here’s a list of everything I did to fix the issues;

Cleaned carbs
Played with mixture screws
Balanced carbs
Set tps
Replaced carb boots
Replaced air filter and spark plugs
Blanked off the previously open balancing points.

I’ll copy this post into another thread I had which talked about some of these problem.

[sirch345]

I’m glad to say the bike it running amazingly now! 95% of the popping on decel is gone, 99% of the clunking is gone (it made 1 clunk noise on an hour ride) idles great now, and low rpm riding is actually pleasant! Thank you everyone for your tips and support, couldn’t have done it without you! Here’s a list of everything I did to fix the issues;

Cleaned carbs
Played with mixture screws
Balanced carbs
Set tps
Replaced carb boots
Replaced air filter and spark plugs
Blanked off the previously open balancing points.

I’ll copy this post into another thread I had which talked about some of these problem.

Well done, good work

Chris.

[sirch345]

This is a fascinating thread. I am about to delve into the world of carbs as a complete novice and all info is good. I’m frantically writing notes to help with what seems to be a bit of dark art. Is there a good thread for general description of how the carbs work on here? Eg very basic like what the different jets are, what the function of the slides etc?

Not exactly basic, but this link here has some of the information you are asking after, it might be worth looking at the first two posts if you have not already:
http://vtr1000.org/phpBB3/viewtopic.php?f=31&t=14214

Chris.