Tuning help

[fabiostar]

get a tin of easy start .pretty much any motorstore/garage sells it, get it running and spray in around the intake rubbers and see if the revs rise.

[Donut 77]

I presume that’s tank and airbox off for good access?

I’m veering towards air leak too atm., it would possibly explain the revs over running - also the front pilot being fully screwed in and not stalling (although that meters fuel and not air?)

It will have to stay as is until after MOT Tuesday, then I’ll start spraying!

[fabiostar]

I presume that’s tank and airbox off for good access?

I’m veering towards air leak too atm., it would possibly explain the revs over running - also the front pilot being fully screwed in and not stalling (although that meters fuel and not air?)

It will have to stay as is until after MOT Tuesday, then I’ll start spraying!

no you dont need to remove the tank, use the straw that comes on the tin and just poke it in around the area you need to get to, to give you a bit more room you could loosen the front of the tank and prop it up an inch or to just, the airbox is as much in the way as the tank really but no removing needed worth a try at least.

[Donut 77]

Thanks for this. Will try tmro. I appreciate any help..

So, to the untrained ear, will it be obvious if there’s a vacuum? I’m assuming it’s a very potent spray..

[xeris]

Thanks for this. Will try tmro. I appreciate any help..

So, to the untrained ear, will it be obvious if there’s a vacuum? I’m assuming it’s a very potent spray..

Yes, think Hindenberg zeppelin at Lake Hurst New Jersey

[fabiostar]

Thanks for this. Will try tmro. I appreciate any help..

So, to the untrained ear, will it be obvious if there’s a vacuum? I’m assuming it’s a very potent spray..

Yes, think Hindenberg zeppelin at Lake Hurst New Jersey

lol yup just what he said

[Donut 77]

In my effort to not over-tighten the carb boots..,

Twas indeed leaking like a bloody sieve.!!

[fabiostar]

I’m my effort to not over-tighten the carb boots..,

Twas indeed leaking like a bloody sieve.!!

aahhh i see said the blind man so the leak has been found then

[sirch345]

I’m my effort to not over-tighten the carb boots..,

Twas indeed leaking like a bloody sieve.!!

aahhh i see said the blind man so the leak has been found then

You da man good call Rob

Chris.

[sirch345]

In my effort to not over-tighten the carb boots..,

Twas indeed leaking like a bloody sieve.!!

I'm glad to hear your perseverance has paid off

Was it leaking on both or just the one carb boot

Chris.

[Donut 77]

Hi Chris,

Yes both, which is not that surprising.., I didn’t do them up very tight..

It was also slightly leaking from the new vacuum port I put in for balancing, but I expected that too. I only used a 4mm spigot, which annoyingly proved not tight enough in 3.2mm ID hose

Also possible leak from where the throttle butterfly pivots. Not sure what to do if it is?. I’ve read about felt washers needing replacing.

Finally I didn’t fully appreciate the importance of the pilot screws on assembly. I just cleaned everything up and put it back carefully. I now know a lot more, so when the carbs come off this week, I will check for the rubber o ring. If it’s present, then it’s only luck, as I didn’t put one in. I suspect a vacuum leak from the pilot screw area too.

Basically, she’s sucking in air from all over, which would explain why it runs lovely above 2.5k, but rough at idle - as the ‘foreign’ air is a greater % of total at lower rpm. At higher revs it’s sucking so much in that it’s too small to affect the ratio. This is my theory at least.,

On a plus note.., took bike out for a 50mile spin after MOT and was grinning all the way round. it’s a LOT of fun…

[sirch345]

Hi Chris,

Yes both, which is not that surprising.., I didn’t do them up very tight..

It was also slightly leaking from the new vacuum port I put in for balancing, but I expected that too. I only used a 4mm spigot, which annoyingly proved not tight enough in 3.2mm ID hose

Also possible leak from where the throttle butterfly pivots. Not sure what to do if it is?. I’ve read about felt washers needing replacing.

Finally I didn’t fully appreciate the importance of the pilot screws on assembly. I just cleaned everything up and put it back carefully. I now know a lot more, so when the carbs come off this week, I will check for the rubber o ring. If it’s present, then it’s only luck, as I didn’t put one in. I suspect a vacuum leak from the pilot screw area too.

Basically, she’s sucking in air from all over, which would explain why it runs lovely above 2.5k, but rough at idle - as the ‘foreign’ air is a greater % of total at lower rpm. At higher revs it’s sucking so much in that it’s too small to affect the ratio. This is my theory at least.,

On a plus note.., took bike out for a 50mile spin after MOT and was grinning all the way round. it’s a LOT of fun…

Thanks for the detailed reply

I think I may invest in a can of Easy Start

I'm glad you enjoyed your 50 mile spin after all the hard work

Chris.