1989 NC30 Hesitation after idling

[franktank]

Hi All,

I'm new round here and this is my first bike so go easy on me!

Anyhow, I've recently purchased a VFR400 of 1989 vintage with 24000Km on the clock. However I've run into a little problem recently.

Trouble started when I slowed down for a car turning off, he went left, I opened the throttle once clear and it was hesitant (15 to 20mph in first) Thought nothing of it and it cleared up. Next I pulled up at a friends and it cut out on me for no apparent reason, however it started first time again. Same evening coming back home, just pulling into my road and it died again, however it wouldn't restart. I left it as it was late and didn't want to annoy the neighbours (It has a none standard exhaust)

Day after started fine, I rode off and about 3 miles down the road realised I'd forgotten to put my ear plugs in, so pulled over with the bike still running and faffed about for 5 minutes putting them in. Pulled off and again a hesitation was apparent between 3000 > 6000 RPM, after that initial hesitation all was fine. Next thing I'm at a junction, waiting to turn, opportunity arises, I go to move off and it just seemed to die (although engine still running) Pulled the clutch in, revved it even higher than normal and managed to get away. After that I lost faith a little in the bike.

Any ideas as to why it would do this? Is it possible to be running massively rich on idle which in turn fowls the plugs a little, hence a hesitation which then clears up? It's been recently serviced (plugs/filters/oil) also

Thanks All

[CMSMJ1]

Welcome..

Sounds like it may be electrical to me - poorly battery and charging system. Have a quick look about and do the checks to the battery and reg/rec.

Loads of yam yams on the site. Wolves is the new Mecca...

[franktank]

Welcome..

Sounds like it may be electrical to me - poorly battery and charging system. Have a quick look about and do the checks to the battery and reg/rec.

Loads of yam yams on the site. Wolves is the new Mecca...

Hi,

Thanks for the info. Checked the regulator and it's fine (was replaced not too long ago) I've got around 14v whilst running (and idling) and it doesn't seem to move much. The battery however, can not crank the bike over for too long (I had a slight starting issue a while back) Maybe worth a try before anything else maybe?

I've only seen one VFR400 so far round here, quite often on the M6 getting off at J10 to go down the Blackcountry Route at around 5:10ish. Wondfer if it;s someone on here?)

Thanks agin

[Neosophist]

Hah, Mark I think you're right!

Theres quite a few guys on here from around the area

DK-Tandy - West Brom,
Walsall and
Porndoguk- Wolverhampton too!
Chownsy

Ricky (PorndogUK) is from Wolverhampton and has a silver NC30
Argh I can't think of his username but is from Walsall.. could be him.

Probably more too, I forget.

I also hail from the area too but don't live there anymore so it wouldn't be me, although I used to use the ZXR more down the M6 than the VFR's.

Is it a white VFR? I've seen that a few times...

Anyhow.

Since it's a new bike you've brought, why not give it a good service.

Get the tank off, check and adjust the valve clearnaces (will be peace of mind and not need doing for a while) then follow Cammo's carb-guide and clean / overhaul the carbs and set them back up to factory specs.

Sounds like your batteries old so get a new one while your at it.

These bikes have often had many numpty owners who do 'mods' and mess the carbs up (working on all 4 and not realising the front and back have different bits in them!)

Get it all cleaned, float heights set and all passageways blasted through with air and carb cleaner.

Having done the valve clearances and carbs, balance the carbs and the biek should run like a swiss watch.

I did my NC30 last month after buying it, took about half a day to do the above and it runs like a watch.

Starts on press of the button, idle is rock solid (like somebody has pinned the tacho needle stationary). And smooth throughout the entire rev-range.

Best to do them all as they are all related and once you have the carbs off, clearances are easy enough to check and faffing with the carbs and clearances require a rebalance.

Half a days job to have a sweet running bike!

[porndoguk]

Hah, Mark I think you're right!

Theres quite a few guys on here from around the area

DK-Tandy - West Brom,
Walsall and VFRderek AKA Del
Porndoguk- Wolverhampton too!
Chownsy Birmingham

Ricky (PorndogUK) is from Wolverhampton and has a silver NC30
Argh I can't think of his username but is from Walsall.. could be him.

Probably more too, I forget.

I also hail from the area too but don't live there anymore so it wouldn't be me, although I used to use the ZXR more down the M6 than the VFR's.

Is it a white VFR? I've seen that a few times...

Anyhow.

Since it's a new bike you've brought, why not give it a good service.

Get the tank off, check and adjust the valve clearnaces (will be peace of mind and not need doing for a while) then follow Cammo's carb-guide and clean / overhaul the carbs and set them back up to factory specs.

Sounds like your batteries old so get a new one while your at it.

These bikes have often had many numpty owners who do 'mods' and mess the carbs up (working on all 4 and not realising the front and back have different bits in them!)

Get it all cleaned, float heights set and all passageways blasted through with air and carb cleaner.

Having done the valve clearances and carbs, balance the carbs and the biek should run like a swiss watch.

I did my NC30 last month after buying it, took about half a day to do the above and it runs like a watch.

Starts on press of the button, idle is rock solid (like somebody has pinned the tacho needle stationary). And smooth throughout the entire rev-range.

Best to do them all as they are all related and once you have the carbs off, clearances are easy enough to check and faffing with the carbs and clearances require a rebalance.

Half a days job to have a sweet running bike!

i live in wolves where abouts are you fella?

we also have UberPikey in albrighton and Lip from codsall,

[franktank]

Thanks again Gents,

Porndoguk, I'm in Willenhall so halfway between Walsall and Wolverhampton!

Anyway, to update this, I was left stranded a few weeks ago. Pulled upto a junction and it just died (this was after a good 60 mile ride) Wouldn't restart and the battery died pretty sharpish. Called AA (Luckily included in my insurance policy) and got the bike onto the kerb. Waited 20 minutes, thought I'd try to start it again, bingo, cancelled the AA, got 500 yards down the road and it died again :)

Battery was completely gone this time, so had to wait for AA man to jump start it, the bike lasted just long enough for me to get back.

Anyway, since the breakdown, I've stripped and rebuilt the carbs with 118/120 jets (to replace the 110s) modified the sliders, added the 1mm washer and set the pilot screws as per the guide. Also replaced the vacuum hose to the tap, and stripped it down to make sure everything was OK, and touch wood, it's been OK so far. Also checked the valve clearances, which luckily were all within spec (bike has 24Km on it) and coupled with the full service I gave it when I bought it, I think it OK now.

I think there were a few problems contributing to the breakdown, a small split in the vacuum hose, a battery with a pretty poor capacity (although it's OK for starting assuming it catches within the first few seconds) and probably something else I'm yet to discover!

Anyway,

Thanks all

[CMSMJ1]

Glad it is working..but you need to check the charging rate on the battery asap. Also check the voltage acorss the battery with no load on it - if it is under 13v then the battery is a touch weak.