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Discussion Starter #1
Can diaphrams go bad without being holed or ripped ???.

The reason i ask is i still cannot get to the cause of my misfire on my RD03. I've replaced so many things i've lost count.

I borrowed Roadkills carbs and it went like a rocket, His carb number ends CC7 and mine end CD7, Everything else is the same, jets , mains, needles,float valves etc etc.

One thing i did when i had Roadkills carbs was to start the engine with the air box off and you could clearly see the slides dancing up and down on tickover, when i reassembled mine this morning i did the same and my diaphrams dont move at all till about 3000 revs and seem slugish in rising when opening the throttle unless you quickly open it full.

Ive already taken the diaphrams out and inspected them and theres no rips/holes in them, they are a bit baggy but i would say that Roadkills looked worse than mine.

If the slide isnt rising as it should then this would produce a misfire/ loss of power as it would be starved of fuel at a certain throttle position......................................................................... but the diaphrams look ok.

let me know your thoughts before i blow another £100 on new diaphrams that it might not need :confused:.

Thanks
 

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Holla

God your problem seems to be dragging on, it must be driving you insane!

I'm getting into the realms of guessing now, but it would seem like you eliminated an electrical issue, and at the moment it seems to be point towards fuelling.

What jumps to mind is whether you have a friendly nearby motorcycle doctor (or car for that matter) with a gas analyzer, who could perhaps analyse the exhaust gases, thereby checking the mixture through the rev range? Or perhaps do you have access, or could someone lend you one of those old fashioned Gunsons Colourtunes? That might give you more clues without a massive outlay?

The bit that sticks in my mind is, you said that with your carbs it revs cleanly at a standstill, but misfires when under load (or on the move) is that right? Did all this disappear when with Roadcats carbs?


Bob
 

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Discussion Starter #3
Thanks bob, fed up isnt in it !!! my girlfriend has taken the laces out of my shoes as i'm verging on suicidal :eek:.

Roadkills carbs were dirty outside and sooty inside wheras mine are gleaming and shiny, but with his on it didnt miss a beat and the bike went like a rocket.

As i said his had a slightly different number stamped on them. With hindsight i should have put his diaphragms in mine but i didnt really want to completely strip his down.

I think i'll get the diaphragms done and then kill myself.

Thanks for your ongoing concern Bob
 

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Discussion Starter #4
Or perhaps do you have access, or could someone lend you one of those old fashioned Gunsons Colourtunes?
Demon tweeks do a 12mm one that will fit the plug hole, but i'm worried about the fitting as the main plug holes you need to get to are waaaaaaaaay down deep and i dont know if this would work because of this.

Knowing my luck i'd get it stuck down there and then need an engine strip down then i'm sorry that would tip me over the edge :(
 

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I man with a garage full of Ducatis like yours, and a classy KZ1000 and a spot less Yam RD is not going to be brought down by a spooky RD03

Hang in there!!!
 

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Discussion Starter #6
I man with a garage full of Ducatis like yours, and a classy KZ1000 and a spot less Yam RD is not going to be brought down by a spooky RD03

Hang in there!!!
Dont get me wrong, I'm very lucky to have several other bikes to ride..........................................but all the time i spend on fixing (or trying to) the F!CK*NG africa twin means i cant ride any of the other ones !!!!!!!!!!!! :mad::mad::mad::mad::mad::mad::mad:.

What do you think about the diaphragms before i pack them up and spend another £100 :(:(:(
 

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I think, mark my words, THINK, that if you can not see or find a hole in the diaphrams then they should not affect the performance.

Sure there could be a microscopic hole in there somewere, but then again, if your eyes can't see it, it would not interfere with the performance of the engine, I THINK,,,

I looks as if you by using the borrowed carbs, nailed it down to a carb related fault right?

It did run well with those other carbs right?

Now, I guess RD03 carbs do not pop up every now and then?
So how about all other engines that uses the same 650 mill?

Not the Transalp 650 but the NTV650 Revere



England should be littered all over with these machines ? :p

Check with Dave Silver or someone with knowledge
if you can use carbs from this model, with minor adjustments.

Or perhaps only use the carb pistons with the diaphrams from the NTV http://www.cmsnl.com/honda-ntv650_model1227/

Check number 16111-MS8-004 to see if any other model uses the same part

By the way, the springs on top of the pistons, they are okey?

both carb springs have the same length?

//Kjell

Edit:

According to

http://www.cmsnl.com/products/piston-comp-vacuu_16111ms8004/

only the XRV650 uses these, but all market models and all years (88 & 89) have them.

I know of only one scrapped RD03 in Sweden.
Do you want me to check if the carbs are still on it?
 

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Discussion Starter #10
Thanks kjell, Ive just gone in the garage just to make sure that my sliders didnt jump up and down on tickover like Roadkills carbs WITH THE UNRESTRICTED INLETS ON, as i thought last night.........

" i wonder whether my slides/diaphragms didnt move because i had the restricted inlets on ???"

So put the unrestricted ones on (the ones i got from wemoto) and my slides dont budge a mm on tickover wheras Roadkills ones were all over the place on tickover and that was with the unrestricted ones on (i'd say a good 5mm of up/down movement)

I think i'm on the point of going insane, second guessing myself that it could be this or could be that :mad:.

No pressure Kjell but if you dont fix it for me i will kill myself ;)

Only kidding, but it is beginning to get a bit tiresome now.

Thanks again Kjell and everyone thats with me on this one.
 

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Ian

I really do not know the effects of the restricted spigots on the RD03
But normally that type of restriction would not cause the engine to studder when taken away.
Nor would they affect the need for changing jets.

So I'm too lost in the operation.

Keep your thumbs on monday Ian
If they still have them carbs, I'll send you their contact information.

//Kjell
 

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Discussion Starter #12
ITS FIXED !!!!!!!!!!!

Hi all, Whilst i was messing about with the carbs this morning i decided to alter the float height even though it looked like it was close to the 7mm that the manual says. I adjusted the tang on the float so it was about 8 - 8.5mm and started it in the garage with a remote tank on.

The choke seemed much better (it wouldnt run before on full choke and struggled to run on the notch position on the choke lever) it was just a matter of getting it running then backing it right off, so because of this i was hopefull of some improvement.

I took it down the road and dreaded to open it up in case the misfire was still there................................................ but it wasnt !!

It went like a rocket, as good as it had done with Roadkills carbs on it. I'm very pleased indeed, not only because i've finally got to the bottom of the problem but also because my girlfriend has given me my shoe laces back now i'm off the suicidal list :D:D:D.

Having only done 2-3 miles on it with the float height adjusted i decided to go to my dads ( a round trip of about 60 miles, 30 motorway and 30 A roads) and it didnt miss a beat :p:p:p.

Thanks for all of your help especially Kjell for all of his valuable information, Roadkill for the hire of his carbs and Airwolf for his test ride.

Its not all good news as i've noticed some clunking from the front forks :D:D:D:D.

Onward to the next problem ;).
 

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I love it when im right !! I told you it was the carb not filling up quickly enough. Look at your original thread again(especially post 39) and then kick yourself !!

:D

Really glad its sorted for you.. I know the feeling all too well.
 

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Well done, it sounded like you where only a step away from getting crayons to write with!!!


:D:D:D:thumbright::thumbright::thumbright::thumbright::thumbright::thumbright::D:D:D

So glad you got it sorted.
 

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Err, right... well the carb saga doesn't all end there.

I got some free time to try to put my carbs back in this afternoon and it seems to be, erm how shall I put this ... difficult to say the least.

There seems to be no way that the carbs are going to go back onto the rubber mounts.

I tried judicious use of oil on both the rubber outlets and on the piece of carb that's meant to go into them and I tried giving them some persuasion with a nylon mallet all to no avail. :(

There just seems to be absolutely no flex in the rubber to allow the carb to slip in. The carbs were pretty difficult to get out and required a fair amount of effort and leverage to get out but now that they're out I'm worried they may never go back in!

Ian, those unrestricted manifold mounts you bought are they soft and flexible? You've had carbs on and off several times, how easy should it be? Am I going to need to buy new mounts to get my carbs back on my bike? I know she spent several years sitting outside under a fig (?) tree before I bought her and it wouldn't surprise me if the rubbers had hardened as a result of weather / UV.

Any suggestions as to how I can get my baby back together again people?
 
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