Fuel leak, from Ed

[ED-CASE]

Hi, folks, need a little advice
Bought an NTV650 "for restoration"
Got it running, but lots of fuel leaking
Probably float chambers / floats not floating?
I will remove and dismantle and clean the carbs.......
IF I absolutely have to....
Anyone know a "magic fluid" ?
One that really works to clear choked carburettors ?
Very grateful for any thoughts
All the best
Ed

[odie]

There are products out there that can do the job but taking them off and cleaning them is the only sure way of sorting the problem.
The reason why you are leaking fuel is because you have muck / dirt under the float needle valve, either that or the needle valve seat has worn.
Odie

[ED-CASE]

Thanks, Odie, that makes it unanimous. I'll go buy the bits to do it properly
Wish me luck.
Thanks again
Ed

[ED-CASE]

I have stumbled across a boon tool when removing NTV carburettors
I may be preaching to the converted, but, "I never saw one of these before....."
In "Mill" auto factors, I bought a vice-grips with extension-bars, enabling approx. 9" reach from the jaws to the levers. The fine-teeth and strength against flexing enabled me to twist the heads of the flexi-stub clip-screws, despite being seriously rusted-in AND having clear evidence of previous attempts with posi-drive screwdrivers
Only a few degrees of rotation at a time, but three twists at a time on the screw-heads broke the seizure on each of the four screws.
Happy days
Ed

[ED-CASE]

Whilst there was lots of fine silt at the bottom of the float-chambers, the fuel hoses had dried up and slackened at the t-piece
New hoses and worm-drive clips seem to have fixed the leak, but only tested with gravity-feed so far
Spent the day welding ALL the holes in the (Original, possibly?!) colander, OOPS, I mean silencer
(including making new collector stubs 'cos I'm way too tight-fisted to buy even a second-hand exhaust)
Will try pump-pressure with a remote metal bottle feeding the fuel, tomorrow (I hope.....)
All the best
Ed

[ED-CASE]

Family matters interrupted play for a week or so....
Leaks appear stopped now
Next task is fit CV pistons back in carbs...
Complete with new diaphragms from NRP Carbs, Manchester
Then make up a new throttle return-cable
I'm a pensioner, and too tight by nature to buy new if I can avoid it
If I'm lucky, I will succeed in silver-soldering bicycle brake-cable to the drilled-off original nipples
Then reassemble the airbox, and................
Fingers crossed
All the best
Ed

[McF]

Sounds like good promising progress.

I've been curious about NRP in Manchester. They offer a virtually unique service and despite costs looking high (still around £35 per carb?) they're a d**n sight cheaper than new slides from Honda.

Why Honda ever chose to use diaphragms bonded to the slides never seemed logical to me (unless of course it's to encourage you to spend a lot of dosh on replacement slides!).

Let's hope your fuel leak problems are at an end and that your cable inners work for you - good luck

[ED-CASE]

STILL STRUGGLING!!!!!
Seems now there is a fuel supply problem!
(despite having cleaned the carbs VERY carefully)
So, I will read everything on here I can find fuel-related, and......
Test the pump-supply by hanging an extension-pipe from the carb-feed up to the workshop ceiling
(and putting the end in a can, of course)
Then, if that is working...
Take the carbs apart AGAIN !! and see if there is a blockage I missed
Many thanks for the encouragement
All the best
Ed

[ED-CASE]

It finally started on gravity-feed from a small tank hung from the garage roof, but there were intermittent spurts of petrol from the carburettor vent-pipe.
When I re-fitted the NTV tank, and re-connected the pump, the spurts of petrol from the carburettor vent-pipe became much more frequent, just short of continuous.
I think I need two new float-needles and float-needle seats?
Comments, please
Many thanks
ED

[McF]

It sounds as though you have a problem with your fuel level in the float bowl.
Is it both Carbs?
Have you checked your float height?
It should be 9.2mm on a 650

[ED-CASE]

Many thanks, for the info. Haynes shows 9.2mm, to which I had set the level with the original float needle-valves.
I appreciate your advice, as I am always a little cautious, and find real experience more credible.
Just to be sure, yesterday I asked NRP to send 2 new float needle valves, which came this morning just after 11am.

When I removed and re-examined the old ones, I determined that there was a slight "hesitation" in how they released from their seats. Also the black tips appear to have softened in comparison to the new ones. I also had to subtly re-adjust the float-levels to regain a "touch" closure at 9.2mm of float still showing clear of the carburettor-body. Finally, the OEs have a "square" basal orifice, whereas the new valve-seats are counter-bored to match the ends of the needles.

I have just finished fitting the replacements, but as the beastie is a bit loud with the original silencer in its quickly-welded form, I will wait for tomorrow.....
More soonest,
All the best
Ed

[ED-CASE]

At last, the scrapyard NTV 650 Revere now starts, and even ticks over between 200-300 rpm, once fully warm.
Now for the rest of the minimalist sort-out tasks:
oil, filter, and coolant change, an MoT, add it to the policy, get a tax disc, and try it on the road.

More soonest, and many thanks for all the advice and encouragement.
All the best
Ed

PS
NRP carburation specialists, in Manchester, highly recommended

[rj2para (Bisto)]

Great news, but do you mean 1200-1300 rpm?

[ED-CASE]

AFAIK (in Haynes, perhaps?) the NTV is said to need maybe 1000rpm to tickover steadily.
I'm an old-time firm believer that a very slow tickover is an acid-test of good engine set-up.
Once warmed up, I tried my usual trick of gradually winding-down the NTVs tickover screw.
The engine kept going, right down to where the rev-needle flicks between 200 and 300 rpm.
I haven't road-tested the bike yet, so that tickover setting might be a bit too low.
Is the NTV known for stalling on deceleration, or on sudden throttle closure?
Do you think it would be OK, or harmful, to leave it there, if it doesn't stall?
I will post more as soon as I have got an MoT, and actually test-ridden it.
Any comments would be appreciated
All the best
Ed

[ED-CASE]

First ride was "directly to MoT station for pre-booked MoT, test, then return directly home" as required by law
Passed the MoT with 4 "advisories", rear shock, head bearings, front wheel bearings, "fairing", "not likely to interfere with steering....."

Rear shock definitely limited remaining life, any suggestions re replacement?
Head bearings just took up fine with no "notch" effects
Front wheel bearings on their way to me by mail
"fairing" is actually the rear cowling that partially surrounds the seat, I pop-rivetted some polycarbonate sheet across some fracture-lines, but it still flexes a little too much around the rear light, I'll add stiffening
A few problems remain
Jumping out of 2nd. gear, add weld to the lock-stops, possibly tightening the swing-arm slightly, and checking the rear wheel bearings and shaft-drive bearings

My plan for the 2nd. gear fault is to strip the clutch-side case, check the clutch-drum and plates, and hard-weld and re-grind any worn selector and cam-drum teeth so they mate really well
I'm hoping NOT to need to strip out the 'box ('cos I'm inherently lazy) BUT, I will if necessary
Any comments would be very welcome

Finally, I'm not quite as smart as I thought I was...... I had to raise the tick-over to about 600rpm plus, to prevent stalling in neutral on deceleration as I stop at junctions, etc. Ho, hum.
All the best
Ed