Throttle help

VFR_KID

VFR_KID

VFR_KID

Soldato
Joined
3 Jul 2008
Posts
3,248
Location
Fife way up in Scotland
Hey folks,

Just looking for a bit info here and to see if a mates correct.

Recently I have noticed when the bike is up to operating temps and I open the throttle to give it some welly there is like an initial flat spot then you can fell it pull. close throttle and pen it does it again.

Mate said it is possibly the rubbers on the carb's are perished and letting in to much air which is messing up the mix.

Is it possibly this or something more sinister?

Bikes 1986 Honda VFR750FG, Serviced within last 2000miles (Including spark plugs) new chain and sprockets (Not sure if this matters)

Any help would be great cheers.

Edit: Forgot to say It also received a new Battery and Regulator/ Rectifier within the last 1k
 
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If there is nothing wrong like an air leak it needs the carbs balancing or setting up properly, have you considered dynojetting which would solve all the bogging out.
 
Never considered getting it dynod. will speak to my mate and see how much he takes to do it?
 
VFR_KID said:
Never considered getting it dynod. will speak to my mate and see how much he takes to do it?
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Don't know if dynojetting involves a dyno they just set your carbs up properly and you get what you get, I think they change jets, balance the carbs and sort mixtures out properly, but you need to keep getting them redone,

However your bike is quite old so the likelyhood is the carbs etc would be out of balance, even down to wear on throttle cables and stretching pulling up one slider before the other and then not letting one open fully

You may get quite a big grin from having it all done :D
 
LOL. will certainly have a look into it. it does feel down on power, but maby im just getting to used to it
 
hey vfr kid, if you remember i had the same bike as you ?

anyway I say used to basically A woman pulled out on me ..... you can make the rest up.


anyway said VFR FH750 is going to be written off I feel.

So before they come and take it away are there any bits you may want ? obviously we can take discussions off he boards in regards to costs etc, however I know how rare these bikes are and so do you lol

parts that are easily accessible and removable would include. the New screen as you probably saw in my restore thread and certainly the exhaust which is a Motad Stainless Steel jobbie 4 into 1 which they dont even make anymore :( and which saw as little as 2000 miles since I put it on.

anyway if yer interested give me a shout or post here and we can discuss bits etc.

the bike technically hasnt been written off yet however it will be as the fairings all caput on the left hand side. BTW Exhaust was on the right hand side so is still absolutely mint :) as is the screen as no damage to either.


dunno if i posted the restore thread on here lol

anyway

http://vfrworld.com/forums/1st-2nd-generation-1983-1989/26514-vfr750-fh-restore.html

pics etc in there of screen and exhaust.
 
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Has anyone set up carbs with CARBTUNE gauges?

Im thinking about trying this when i take off the tank to inspect the Carb rubbers due to the above problem.

Is it easy enough. I have done most other mechanical type things. Just never played with carbs.
 
I have set a few up with vacuum gauges if that's what your talking about ? if so obviously make sure you have fuel i use a funnel and keep topping up,bring the bike to working temperature not to hot and not to cold and set accordingly.

Also use good gauges.
 
VFR_KID said:
Has anyone set up carbs with CARBTUNE gauges?

Im thinking about trying this when i take off the tank to inspect the Carb rubbers due to the above problem.

Is it easy enough. I have done most other mechanical type things. Just never played with carbs.
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Be careful on v twins one runs leaner than the other as it will run hotter and not get as much cooling

if you balance varadero carbs up equally it'll heat seize
 
maccapacca said:
Be careful on v twins one runs leaner than the other as it will run hotter and not get as much cooling

if you balance varadero carbs up equally it'll heat seize
Click to expand...

As said above ,also just out of interest some fours run like this inners different to outers.
 
flatspotting is usually down to it overfueling at that point then leaning out. trouble is where it leans out it might be too much. check the colour of a plug - if white tip its running lean badly and needs refetting and setting up before it blows up. if black - its sooty and overfueling. if a touch wet - probably oil. valves need reseating/resealing.

you tend to get better power when its running lean. i had a CBR600 making 103bhp and it used to keep up with quicker 600s at snetterton as i made it run slightly lean. risked blowing it up but it was quick! lol
 
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