running issue. its got me beaten

[Ansimp]

I spoke to Maurice today Joe and his carbs are virtually brand new. As you can see by his videos he is fastidious in his building of his machines. I feel his running issue may be related to the fact he has a brand new engine that only has about 300 mikes on it and just needs to bed in properly. He sent me his video and in a no load situation I can barely notice it. If I can I will try and post his video so that you can all have a listen.

 

[slabghost]

Ahhh That 'splains a bit! A perfectionist is rarely satisfied.

 

[joedrum]

that be cool ....i had a 79 that did this also ...when i got it ..it had 10000 miles on it ... it was five yrs till i finally sync the carbs at the rpm and thottle possition that was doing all the farting around running ...when i did it ran good there and would hold a steady cruise without hiccuping...i was very glad seemed like it was 80% of all my riding

 

[ekvh]

I think the waste spark creates a lot of the uneven-ness of the flat four engine. Does the C5 ignition work with the waste spark, if so you have three healthy sparks released in the exhaust stroke. If you have anything left in the cylinder or exhaust pipe, it's going to make for an ill-timed gurgle. Porshe's and VW's and Subaru's are known for a sloppy sounding idle and irregular sound at speed. Get enough of it going down the pipe with the right ratio and you get some good pops. I would love to hear a Goldwing without a waste spark to see if it's any batter. These is just opinions, here, so fire away.

 

[joedrum]

you know eric the c5 is wasted spark system and i to feel the same way on wasted spark ....but with the weber the motor dose none of these stock bike things that happen and this thread is about ...so i beleave now its all about the stock carbs ...maybe the flat 4 is so balance that imperfections get even worse... but when things line up right it dont get any better .... the c5 and weber are perfect pertners it seems

 

[ekvh]

I have the parts, just got to find time to do it. I have a 32/36 which I know is probably too much, but going to try it first with some mods. Wish I had the coins for a C5. I might have to sell a few things.

 

[Steve83]

Has anybody tried to mod a distributor to be driven off the left head? No reason it shouldn't work...

 

[joedrum]

randakks had a pic of one that didnt run yet i never seen it again ... not sure he ever finished it

 

[Ansimp]

Wasted spark is the firing of 2 cylinders at once and only is on the combustion stroke. The C5 main improvement is multi sparking during the combustion stroke.

 

[Ansimp]

There is already no room for my size 11s, image if there was a distributor in the way. This does remind me that the Subaru ea82 engine has a cam belt driven distributor off the LH bank.

 

[Steve83]

Ansimp » Thu Sep 25, 2014 2:15 pm[/url]":38fa1fx9]
Wasted spark is the firing of 2 cylinders at once and only is on the combustion stroke. The C5 main improvement is multi sparking during the combustion stroke.

It does fire 2 cylinders at once - one is on the compression/power stroke while the other is on the exhaust/intake stroke. Most newer vehicles, unless they use coil-on-plug, are wasted spark ignitions. Simple and effective, as long as things are working properly!

 

[dan filipi]

Yeah I would think 1 let alone 3 sparks happening would cause some interesting pops and flamage out the pipes but I've never heard any, even with all the rich carb setups I've run, single and stock rack.

 

[slabghost]

Exhaust is still burning gas anyway so added sparks make no real difference.

 

[aussiegold]

yes, i'm a perfectionist.... :roll: it's a character flaw. :wave: but this engine should be purring like a kitten. it isnt. the wavering tach and slight up /down on the bike lift translates into an annoying surge/ hesitation at a steady throttle.
i can see how a single carb is a good option for some but for me ( and this bike) the stock is the way to go. i will find the problem, eventually. logical thought dictates that that is the only outcome if i persevere. :smilie_happy:

 

[Ansimp]

Here is the running video of Maurice's 75
[video]https://youtu.be/iT-jSE8lFVE[/video]

 

[joedrum]

ok ......ausiegold ...this is only like brain surgery .... if the carbs passages are all clear... the only thing that can cause this ...and the video shows it is one or more of the carbs ...the slides are fluctuating just like the rpm on the video.....as stated earlier at this rpm ...where the vacuum that controls the slides is struggling to keep slides steady needs to be adjusted.....not only that ... if you adjust the sync screws one carb at a time you can find the offending carb...cause you can take the fluctuating carb slide and adjust it steady ... when that is figure you have offfending carb or all the carbs are suffering

for syncing to work like its suppose to in the cv type tech for carb each carb has to be perfect also in its complete form ... this is not something mass production dose well ...it can be very close and still be enough difference to have problems just off idle.....the greatest carb rebuilder on earth with rack only to work with could never get the carb right or even know there is a problem without it being on the motor and running ......

as said before ...in the video ..the rpm that gives the most problem is where you need to sync the carbs ...i dont care what the gurus and manuals say ...this is where this motor struggles and obviously is where you need to adjust it ...plain common sense and a perfectionest attitude will get it to run great at this rpm ... when that is done ..idle and other spots will be ok or the best it gets....obviously syncing at idle did not even out the rest of the running ...so go to the worse spot you have and work there.... this is how a perfection of operation happens .....sometimes one can go by the book and everything works out great... but sometimes not .....one thing for sure about oldwings ...it common that doing everything right doesn't get it on a lot of stock carb racks .....seems like when one get there ...most blame the capabilities of the wrencher as fault and this is simply not true ....as i remember it on my 79 that ran like this ...it took a full day of screwing with the sync screws and mix screws to get it to perform good and smooth ....on such a touchy borderline carb system as stock racks are ...truth is on some bikes this can be very difficult to get right

but as said before starting at the trouble spot is great first move ....

 

[dan filipi]

Ansimp » Thu Sep 25, 2014 11:15 pm[/url]":2odlgyhv]
Here is the running video of Maurice's 75
[video]https://youtu.be/iT-jSE8lFVE[/video]

Gees, what's wrong with that?
Only a very slight variation in rpm which can come back to actually being the tach.
No load sound out the exhaust is one thing, how does it do on the road?

 

[slabghost]

I agree with the advice already given however fuel mix screws all set the same tells me somethings not right. To get them adjusted right you start with one at idle warmed up. Adjust the mix screw to the highest rpm you can get. Reset the idle and do the same to the next. Do all four twice. Once done you may find the issue is less or gone. If it's still not perfect at rpm set synch at 3k rpm.

 

[Ansimp]

I spoke to Maurice tonight and he said the variance on the road is quite pronounced. He cleaned and rode his ltd today and confirmed how the 75 should be running. His last statement is the " 75 is not coming off the lift until it is sorted" so I am sure it is only a matter of time before he gets it sorted :good:

 

[slabghost]

Also might want to add ATF to the fuel. Todays ethanol fuel mixes don't run like the fuel did when these bikes were made. He'll get it right yet I'm sure.