40 replies to this topic

[Studley Ramrod]

I mentioned valve timing out as I ran my old mk1 with the timing out (can't remember if it was one or two teeth out) and it gobbled the gas.  Chain stretch maybe won't be as severe.

I also got through  nearly a tank of fuel in less than 100 miles coming up a very wet A1 and the bike was only firing on 1cyl.

[fixitsan]

I mentioned valve timing out as I ran my old mk1 with the timing out (can't remember if it was one or two teeth out) and it gobbled the gas.  Chain stretch maybe won't be as severe.

I also got through  nearly a tank of fuel in less than 100 miles coming up a very wet A1 and the bike was only firing on 1cyl.

 

That sounds like it's due to holding the throttle wide open to just keep it going, especially on one cylinder where you're getting half the torque but using full fuel !

[oldman]

I had a similar problem,vacuum fuel tap was leaking into the manifold via the vacuum pipe.If I left the fuel turned on overnight with a full tank I would get hydraulic lock when starting the next day,People riding behind had a strong smell of petrol.New pump diaphragm cured the problem.

[Studley Ramrod]

 

That sounds like it's due to holding the throttle wide open to just keep it going, especially on one cylinder where you're getting half the torque but using full fuel !

 

Yep, flat out at 70mph.

 

I had a similar problem,vacuum fuel tap was leaking into the manifold via the vacuum pipe.If I left the fuel turned on overnight with a full tank I would get hydraulic lock when starting the next day,People riding behind had a strong smell of petrol.New pump diaphragm cured the problem.

 

Sidey had the same problem with his mk2.  Oil stunk of fuel and the hydraulic lock blew the carbs clean off the inlets when he tried to start it, also blew fuel all over the bike.
 

[dandywarhol]

FP tubes are much harder than Yamaha ones so eventually they will wear the needles

[JA83]

I'll give it a try, the chain that is. Not just for the fuel consumption but it might be smart anyway due to smoothness.

About the needles. There is a distinct difference between the two sets I have, one is fat and one is thin. The "stock" ones are fat and ones I have it it now are the thin ones, which should be the FP ones.

I ordered new rubber hoses for the airbox->carbs connection.(not flexible at all) Which is the main reason for not dismantling the carbs last summer. Give it a clean and rebuild with the same jets since no one, my interpretation, commented on the setup.

[Favs]

Too late but      Wintergreen

 

https://www.youtube....Aar1Ilfs&t=448s

[dapleb]

Peeps who had FP needles seemed to have to fart around alot to try and set them up whereas OEM needles with FP toobs straight forward. I don't think this explains the mammoth consumption though.

Aggrozzle chain first step and once you know no timing issues go from there.

[JA83]

Yeah, saw that wintergreen stuff, but for some reason it costs like 20 gbp for 10 ml here in Norway and I can't find anything local here in Oslo either.

And at a 1/3 ratio AND the need to submerge it...= buying new😌

[JA83]

One last question..🙄
Does anyone know the psi on the original vacuum pump? (tdm 850 3vd)

[Studley Ramrod]

Well, problem is that I don't really remember when the consumtion went up. After or before the rebuild, had the motor in 200 parts and the whole "bike" of the frame. This was last summer.

New pistion rings and valve steam seals = no oil consumtion though. Also I have a third gear again!

The milage is 130 000 km, 80 000ish miles.

 

I've the FP tubes in it, but they are like 5 years old probably. But they should wear out?

 

Heavy right hand for sure, but I don't get higher mpg even if I drive as a granny.

 

Regarding the choke, it might be the case. I changed the plungers a few years ago. But the mechanism isn't running completely smooth. Also if the timing can cause this that might be the case. The chain is really streched out, I'm almost one tooth off. So the timing might actually cause this?

 

This is my setup now.(Know the starter jet is waaaaay to big, gonna change it back)

The wildcard here is also the fuel height as I had a pain is the a** to get it correct, gave up and ended up riding it instead

Bike is running really well though, just the consumtion that is off. I smell fuel but it doesn't appear on the ground.

 

Supplier Part Size Comments

NRP carbs Pilot jets 42,5 Pilot screw at 2,5 turns

Wemoto Main Jet 142,5  

Wemoto Primary Main Jet(Starter) 142,5  

Factor Pro Emulsion tube PN: CRZ-EMU-100120k  

Factor Pro Needle 1175-90q-70r-45t_ti Third notch

Biltema Exhaust - Without DB killer

Wemoto Air filter - "OEM"

Biltema Fuel pump 120 l/h, 0,3 bar  

Malpassi Fuel regulator 0,1-0,5 bar FPR007, not sure what pressure I'm at -

Fuel height - Not sure, think I was aiming for 8 mm over the line

Noticed last evening, whilst perusing the Haynes book of wonderment, that your main jets are way too big, they should be 140 not 142.5.  Your primary main jets should be 75, not 142.5 and your pilot jets should be 37.5 not 42.5.  Sooooo, might be worth reverting back to standard and sorting out the sticky choke.

[Bjørge]

Yeah, saw that wintergreen stuff, but for some reason it costs like 20 gbp for 10 ml here in Norway and I can't find anything local here in Oslo either.

And at a 1/3 ratio AND the need to submerge it...= buying new😌

Hi, fellow Norwegian! Where do you live? I may have some jets lying around...located in central Asker

[Dickiebig]

So what sort of miles would you guys expect to be getting from a tank brimmed to just going onto reserve. Rough estimate, out of curiosity

[dablik]

So what sort of miles would you guys expect to be getting from a tank brimmed to just going onto reserve. Rough estimate, out of curiosity

 

150-160 Dickie, at least that was on my original mk1 blasting along the Autobahn the carbs had just been rebuilt so may make a difference..then 3 litres reserve but it's a bassad to catch in time..

[Bjørge]

Mine used to do 290-300kms to reserve

[Dickiebig]

Thanks guys that gives me something to look at and as I've only done one tank full I'll have to get out more 😁👍

[JA83]

Bjørge, Oslo. Skøyenåsen 😎
Have you sold yours?

Update here. Just dismantled the carbs. Choke plungers are shot.. Again, I changed them three years ago. Flat, flat and flat 😬
Orded new tips at NRP.

[Studley Ramrod]

What type of petrol are you using ?  Just wondering if anything above e5 might start perishing them.

[JA83]

Normally run 95 from "Esso", think the addition is sub 5%.

[Studley Ramrod]

I once had a small piece of choke plunger stuck in the recess where the plunger sits, might be worth a close inspection of yours.  Strange that they're boogered after 3yrs.