Docs Thirsty Bike Discussion

[Jakobi]

First ride 2020 yesterday. I jetted the bike exactly the same as my previous bike (300 EC 2019) and the fuel consumption is far too high.

I wonder why the fu*k I can get all my mates bikes right just struggle with me own one. Bloody hell!

20? C, 300 EC 2019

MJ: 180
PJ: 42
AS: 2
JD-RED: #3

Consumption was 3,75 liters for 29,7km in easy terrain, but only gears 1 to 3.
That's too high. My previous bike at the same track with same jetting would have used 2,75 liters.

Yes, my float height is right and the bike didn't spill any fuel, I also have the overflow hose looped acc. JD's recommendation...

I wonder if the smaller PJ 40 would help but fear to get the bloody lean hang after steep climbs

Efficiency! Head mod all the way. Squish clearances can be all over the shop. Nice tight tolerance, jet and forget!

 

[Doc Brown]

Efficiency! Head mod all the way. Squish clearances can be all over the shop. Nice tight tolerance, jet and forget!

I know what you're talking about but first want to see if I can get it right without opening the engine.
Problem is our borders are still closed and I can not test on my common play ground and have to wait when my friends buddy allows us to ride on his land...

 

[hannesd]

I know what you're talking about but first want to see if I can get it right without opening the engine.
Problem is our borders are still closed and I can not test on my common play ground and have to wait when my friends buddy allows us to ride on his land...

i opened my own cilinderhead too at no costs.
at least you'll get an idea of the squish, if you at least have some solder at your home? i did this and then just put a thinner base gasket and the bike runs amazing now (even better then before) i went from 1.2mm to 1mm squish on my '15 ec 200.
the base gasket was cut from a gasket sheat i had laying around and happend to be exactly what i needed,so lucky me

so start by measuring your squish or you'll be chasing a ghost...

 

[Doc Brown]

i opened my own cilinderhead too at no costs.
at least you'll get an idea of the squish, if you at least have some solder at your home? i did this and then just put a thinner base gasket and the bike runs amazing now (even better then before) i went from 1.2mm to 1mm squish on my '15 ec 200.
the base gasket was cut from a gasket sheat i had laying around and happend to be exactly what i needed,so lucky me

so start by measuring your squish or you'll be chasing a ghost...

Nah Hannes, it's not necessary to measure the squish at this moment. It's a carb problem not an engine problem. I need to get out 10km per liter at least. Currently the engine uses about 1,3 liters per 10km.
It's easy to reduce the fuel consumption I was just wondering why all 4 other 300's I jetted the very same way used around 1 liter per 10km but the only one that drinks is mine.

I'll simply try a needle that's a half clip leaner and/or reduce the pilot jet from 42 to 40. I will get this right in less than an hour but the real problem is: I can't ride at the mo...

Thanks for your help, much appreciated!

 

[Jakobi]

Nah Hannes, it's not necessary to measure the squish at this moment. It's a carb problem not an engine problem. I need to get out 10km per liter at least. Currently the engine uses about 1,3 liters per 10km.
It's easy to reduce the fuel consumption I was just wondering why all 4 other 300's I jetted the very same way used around 1 liter per 10km but the only one that drinks is mine.

I'll simply try a needle that's a half clip leaner and/or reduce the pilot jet from 42 to 40. I will get this right in less than an hour but the real problem is: I can't ride at the mo...

Thanks for your help, much appreciated!

It's an engine problem.. not a carb problem.

Same carbs, same jetting specs..

Inefficient engine for sure!

 

[hannesd]

Nah Hannes, it's not necessary to measure the squish at this moment. It's a carb problem not an engine problem. I need to get out 10km per liter at least. Currently the engine uses about 1,3 liters per 10km.
It's easy to reduce the fuel consumption I was just wondering why all 4 other 300's I jetted the very same way used around 1 liter per 10km but the only one that drinks is mine.

I'll simply try a needle that's a half clip leaner and/or reduce the pilot jet from 42 to 40. I will get this right in less than an hour but the real problem is: I can't ride at the mo...

Thanks for your help, much appreciated!

have you concidered you might be loosing all that excess fuel?
did you loop the overflow line to prevent some of the loss? (graham jarvis mod)

also, we shouldn't discuss this here, this is THE database ;-)
maybe start a new thread? and mod can erase previous posts to keep it "clean"?

 

[Doc Brown]

It's an engine problem.. not a carb problem.

Same carbs, same jetting specs..

Inefficient engine for sure!

I bet its not and I will proof that, but currently unable to test. Got 4 Gassers, all 300 EC's (two 2018 and two 2019) in my garage, all on same specs and jettings only one being a drinker. Mine. I am sure I made a mistake somewhere... I think it could be the float height.

 

[Doc Brown]

have you concidered you might be loosing all that excess fuel?
did you loop the overflow line to prevent some of the loss? (graham jarvis mod)

also, we shouldn't discuss this here, this is THE database ;-)
maybe start a new thread? and mod can erase previous posts to keep it "clean"?

I did the JD loop on all my bikes, the bike did not lay on its side a single time.

U r right, I wont write anything in here anymore. Sorry!

 

[hannesd]

can you do a compression test on the 4 gassers you have?
or maybe even by the feel you can sense a difference in compression on yours?
(still thinking about squish/compression)

 

[Jakobi]

Do all bikes have the same part number on the CDI?

 

[Zman]

If you are pretty confident the carb is the problem, swap carbs with one of the other bikes to confirm you theory.

 

[Doc Brown]

If you are pretty confident the carb is the problem, swap carbs with one of the other bikes to confirm you theory.

I tend to try this, but makes no sense if I can't test ride. I try to get a permission to ride on a private property on Saturday.

If I get the permission and the weather is acceptable, we have LOTS of rain at the moment, I'll come back with what I have found.

 

[Doc Brown]

can you do a compression test on the 4 gassers you have?
or maybe even by the feel you can sense a difference in compression on yours?
(still thinking about squish/compression)

I have no compression tester at hand, from what I feel from riding the GP (70 hrs) is strongest, followed by my new one (6 hours). My former EC (100 hours) is the weakest. The fourth bike, an EC 300 isn't mine so I don't want to ride it without the owner being present.

Do all bikes have the same part number on the CDI?

My two EC's have the same p/n, the GP of my mate has a different one. The other EC I don't want to touch as it isn't mine.

Just to repeat, we're not talking about a serious problem, the bike runs fine (except the clutch squeaking), starts fine, idles fine and has no hanging idle. It really rips and it pulls way harder than my other EC and almost as good as the GP which is more aggro down low but loses a bit on top.

All I want is to get the fuel consumption improved. I have several possibilities, smaller PJ (currently 42), using a different needle ( I have two identical ones that are just half a clip apart) or just check the float height again.
First step is I will replace the 180 main jet with a 172 (I used on the other bikes) but I doubt it's that though I was going WOT in second and third gear very often...

 

[Doc Brown]

Yesterday I found a needle/set up recommendation from Jakobi that I copied into my personal jetting file . I tried that and it felt pretty good on a fire road.

I will test hopefully on Saturday if it doesn't rain cats and dogs, then report back.

 

[Doc Brown]

My yesterdays test was for the birds and though I can say that the NECW works well I expect the NEDW or NECH to be even better.

Spooge is less but I can say nothing about the fuel consumption (yet). Had a hanging idle with the AS 2.25 and later 2 turns out. Stopped at 1.75 turns, So far so good.

Conditions where a drama after 48 hours of rain and on most steeper downhills I was nothing but a passenger. Steep climbs I can do with ease under dry conditions were a nightmare and my bike was lying upside down on a steep slope for at least ten minutes.

So a lot of fuel was spilled. I needed 3 hours for 12 miles, I guess that says it all. But I will, as soon as I get the chance to ride again and the needles arrive from the Netherlands continue my testing.

If I am not happy I can always return back to the very nice setting with the JD_needles. And, I hope that in a few weeks the STIC will arrive

 

[hannesd]

hard to imaging it's raining cats and dogs in Austria and we're having (a Belgian) summer
how come you managed to let your bike lay upside down for so long

 

[Doc Brown]

hard to imaging it's raining cats and dogs in Austria and we're having (a Belgian) summer
how come you managed to let your bike lay upside down for so long

Yes, the weather is a real drama. Since about three years we have the common April weather in May. Sun shines while it is pouring.... I am pretty sick of all that rain and the low temperatures

Well, the answer is pretty simple. I could not lift it up. It was on the steepest part. I could not even stand there. And it was muddy as fuck. I could not pull it while it was laying on its side as the bars where about 10 inches in the ground... And I was alone because none of the guys wanted to try that climb. Took a while till they came back to rescue me

 

[Doc Brown]

Update:

Yesterday I could ride my gasser for about 3 hours and the result of the measures (see below) have helped to reduce fuel consumption from over 13 liters for 100kms to 9 liters. That means one tank should last for slightly over 100kms (62mls).
I can live with that. Spooge is too much still but I see no way to reduce it.

Changes I made:
NECW in clip 3
40 pilot jet instead of 42
GasGas GP cylinder head with 0.25mm less squish.

Bike runs well, had to reduce idle speed and ended at AS slighty less than 2 turns out. Temperature 66F/19C, Altitude 660ft/200m.

Unfortunately I and the bike suffer from a whiskey throttle. While I am waiting for a new handlebar, handlebar screws (bent), handlebar clamps, upper triple clamp, handguards, front and rear fenders I try to get rid of the pain in my body and especially elbow.

 

[Doc Brown]

Another update.

Rode the bike on more open trails allowing 4th, 5th gear and the fuel consumption was better than last time (see above).

I kept the carb set up. Just opened the air screw a tad (less than 1/4 turn) and raised the idle slightly as the temperatures were pretty high (85F).

Bike used 8,34 liters for 100kms. I am happy with that, so the problem seems to be solved. From almost 13 liters to about 8 is a significant reduction. I am happy now

 

[hannesd]

8.34L/100km is real good, it won't get better then this.
what's your current squish?