Sluggish running and poor throttle response

Forum rules
Please can you post items for sale or wanted in the correct For Sale section. Items / bikes for sale here will be removed without warning. Reasons for this are in the FAQ. Thanks
Post Reply
Tonybv9
Settled in member
Reactions:
Posts: 4
Joined: Tue Jun 20, 2017 8:32 pm
Sluggish running and poor throttle response

Post by Tonybv9 » Sat Aug 19, 2017 10:04 am

Hi everyone.

My NC35 tank had rust in it, so I did the POR 15 3 stage refurb and it looks really good. I also partly dismantled the fuel tap and cleaned some crud from inside it. I'm pretty sure I put it back together correctly. The diaphragms looked OK.

After reassembly the bike took a few goes to start, and now it won't idle, and the throttle response is sluggish, a bit like fuel starvation.
Obviously the main suspect is anything that got worked on, but what else could I consider? The bike is completely standard.

Thanks

Tonybv9
Settled in member
Reactions:
Posts: 4
Joined: Tue Jun 20, 2017 8:32 pm
Re: Sluggish running and poor throttle response

Post by Tonybv9 » Sat Aug 19, 2017 10:42 am

After reading through the forum a bit more, I double checked the vacuum pipe. It wasn't fully seated, and looks to have a small split at the end. The bike runs better now, but I'll have to take it for a run tomorrow to check.
I'm looking at a new hose and maybe replace the fuel hose too. I hope that's it.

saltysealion
Settled in member
Reactions:
Posts: 51
Joined: Tue Oct 27, 2015 6:45 am
Re: Sluggish running and poor throttle response

Post by saltysealion » Sat Aug 19, 2017 12:50 pm

Glad you found your solution!


Makes me want to check mine too and actually secure it down :)

Minimoto
Settled in member
Reactions:
Posts: 75
Joined: Wed May 24, 2017 8:53 pm
Re: Sluggish running and poor throttle response

Post by Minimoto » Sun Aug 20, 2017 5:14 pm

Hi. I could do with cleaning my tank up a bit. Could you let me know what a POR 15 3 stage refurb is? Cheers, Dave

Sent from my Nexus 6P using Tapatalk

Suzuki416
Familiar Member
Reactions:
Posts: 298
Joined: Fri Aug 26, 2016 10:17 am
Bike owned: 3 x NC35, 3x NC24, NC29, RC46
Location: London
Re: Sluggish running and poor throttle response

Post by Suzuki416 » Mon Aug 21, 2017 1:05 pm

i did my wifes CBR400 tank using hydrocloric acid & water...worked amazingly. Can post full details if required

Minimoto
Settled in member
Reactions:
Posts: 75
Joined: Wed May 24, 2017 8:53 pm
Re: Sluggish running and poor throttle response

Post by Minimoto » Sat Aug 26, 2017 10:51 am

Yes please...

Sent from my Nexus 6P using Tapatalk

Suzuki416
Familiar Member
Reactions:
Posts: 298
Joined: Fri Aug 26, 2016 10:17 am
Bike owned: 3 x NC35, 3x NC24, NC29, RC46
Location: London
Re: Sluggish running and poor throttle response

Post by Suzuki416 » Sat Aug 26, 2017 12:18 pm

Removing Rust from the inside of Fuel Tank Walkthrough

I have just restored my wifes rusty (on the inside) fuel tank on her CBR400 (NC29) & thought I would share a few lessons I learned on route:

For very light Rust
Cider Vinegar (£11 for 5 litres) will do the job - you will still need to use the Bicarbonate of Soda to flush the ‘acid’ & it may take a few days for it to work..


For Heavy Rust
You will want to use Hydrochloric Acid.. - £26 for 5 litres.

I followed the 2nd method & too be honest its a much faster & better job - if you are CAREFUL.

I decided to do this outside – the fumes from the acid are really toxic - & doing this inside REALLY IS CRAZY.

Items required
Rubber nitrile gloves, glasses, pump to suck out fluid, hose pipe, a stand for the tank, Hydrochloric Acid, box of bicarbonate of soda (Wilkinson sell a really cheap box), Gaffer Tape (Duct tape), funnel & a couple of tools.
First, empty the tank completely – use the pump to suck out the dregs of fuel, then remove the fuel tank filler cap & fuel tap.
Block the fuel tap hole (zip tie a hose on it with an old bolt on the other end).

WEAR THE PROTECTIVE GEAR FROM THIS POINT


Pour 4 litres of tap water into the tank then add 1 litre of acid (it really doesn’t need to be exact measurements) - Be really careful not to inhale the fumes & then cover the filler hole – stops getting acid splashed when you agitate the tank & also stops the fumes - I used the duct tape – but an emergency plastic filler cap may do a better job.
Slosh the tank around every couple of minutes – I checked every 5 mins & had to replace the duct tape each time as it partially melts - lol.
After just 20 minutes the acid had done its magic & the rust had gone from the tank – it ends up as sludge in the bottom of the tank, so I emptied the acid into the container & sucked out the rest using the pump.
Now onto neutralising the acid.
1. Fit the plug back onto the fuel tap.
2. Fill the tank with water from the hose, slosh it around & then drain.
3. Add ½ cupful of bicarbonate of soda to 4 litres of ‘warm’ tap water (from the hot tap – NOT BOILING WATER FROM THE KETTLE) in a container, give it a good shake / stir to mix it & then empty it into the tank. Seal the filler, give it a really good shake, then gently agitate the tank for a couple of minutes, & then drain it.
4. Fill the tank with water from the hose, slosh it around & then drain.
5. Add ½ cupful of bicarbonate of soda to 4 litres of ‘warm’ tap water (from the hot tap – NOT BOILING WATER FROM THE KETTLE) in a container, give it a good shake / stir to mix it & then empty it into the tank. Seal the filler, give it a really good shake, then gently agitate the tank for a couple of minutes, & then drain it.
6. Fill the tank with water from the hose, slosh it around & then drain.
7. Now totally drain the tank to remove any water from inside – I used compressed air & the pump to drain it, then refit the fuel tap & filler cap.

All done.

If you want to add POR-15® Fuel Tank Sealer then now is the time.

This is not a 10 minute job. – lol

User avatar
Tim400GB
Site Supporter
Site Supporter
Reactions:
Posts: 1168
Joined: Mon Jan 04, 2010 7:24 pm
Bike owned: 1 x NC30, 2 x NC32.5,
Location: SE Greater London
Re: Sluggish running and poor throttle response

Post by Tim400GB » Mon Sep 11, 2017 1:25 pm

The VFR and RVF tanks are well sealed from the factory, vary rarely do I see these tanks rusty inside.
I would advise against cleaning them out with any acids etc unless you plan to seal the surfaces immediately with something like POR15


Post Reply