Topic: running really rough, desperate need of advice--- *Problem SOLVED!!*

[fdbrat]

What grade gas are you running?

Try running it with out the air box.

[Bru-tom]

^^^^ hahahahahaha and to think, it was only an 80

then its a great thing that i never made the same mistake

What grade gas are you running?

Try running it with out the air box.

its our Lead Replacement Petrol, Closest we have to 95 octane leaded.

then i may as well run pods, right? I mean, if i run it without the filter on my plenum modded filter, it still runs rich.


Doesnt anyone think my advancer spring could be shot? like Hondaman states, they do get annealed and soft over the years. I dont really know how an advancer will effect the ride if it kicks in too soon?

[harisuluv]

One thing at a time.  You are starting to wander again.  You need to eliminate air leaks in your manifold to cylinder head and then your boots. 

You can figure out what to use and avoid getting your paint, people do it all the time.  you don't need to spray it at power washer levels, you just need to use common sense.  It is perfectly safe if you just don't get stupid.

AFTER that you can start to eliminate the next thing.  You have more than enough "suggestions" to pursue.  Don't start speculating on other things yet.

[fdbrat]

I've never ran anything but 87 octane.

I believe that running the higher octane will change your ignition timing.

Some one who knows better than I might have advice for running the timing different for a higher octane.

[Bru-tom]

One thing at a time.  You are starting to wander again.  You need to eliminate air leaks in your manifold to cylinder head and then your boots. 

You can figure out what to use and avoid getting your paint, people do it all the time.  you don't need to spray it at power washer levels, you just need to use common sense.  It is perfectly safe if you just don't get stupid.

AFTER that you can start to eliminate the next thing.  You have more than enough "suggestions" to pursue.  Don't start speculating on other things yet.

thanks for keeping me at bay Mr, appreciate it. I will see what i can do tomorrow wrt the air leaks etc, then like you said, move to the next item on the list.

I've never ran anything but 87 octane.

I believe that running the higher octane will change your ignition timing.

Some one who knows better than I might have advice for running the timing different for a higher octane.

yep, hoping someone can assist

[Bru-tom]

should the vacuum screws in the intakes have o-rings?

[harisuluv]

should the vacuum screws in the intakes have o-rings?

No there are no o-rings there.

[Bru-tom]

cool cool, i have brass screws and brass washers there, so i should be sorted there

[DustyRags]

For flammable things to test for air leaks, think gas- propane torches with the gas flowing (but not lit) are a common one. I imagine you could try getting a butane lighter and cranking the flame really, really big on it, and that might give you enough gas too. Or even an oxy/acetylene torch running just the acetylene.

For the idle jets, make sure your passages are clear too. I had that issue recently on my 2000 CB750- my idle jets weren't firing, but the jets were clear. Turns out the idle passage was clogged. Had to spray a lot of carb cleaner and compressed air through there, and finally ran a nylon brush bristle through it. That did it- runs great now.

[Bru-tom]

thanks mate. id be nervous to introduce a flammable gas like that, but i do have a propane torch i could use. It wont damage anything hey? So i run the bike and just blow the gas onto where i would suspect a leak and wait to see if the idle increases?

wrt the idle jets and idle passages, i tool a 4mm ID clear tube and shoved it onto where the idle jet is screwed in, with the jet removed and blew really hard through the pipe and it was clear and the same for all four.it came out the main jet iirc and near the slide...

my jets must be firing though?

[harisuluv]

Can't say that I like that method of cleaning the idle passage.  You're essentially just relying on compressed air, it has no real "cleaning" properties.  It is not a solvent and will have no affect on lacquer or contaminants inside that are anything but free floating. 

That's why usually compressed air is usually following carb cleaner to remove anything that dissolved and then confirm free flowing air.  Just because air comes out the other side does not mean that the passage is clear or that the passage is not restricted.

 

[Bru-tom]

got ya, new task for tomorrow! thanks guys

its not the method i used to clean the passages, that was done a while ago, the pip is what i used today to double check the passages. but its not guaranteed as you explained to be CLEAR...

where do you apply the carb cleaner, into where the mixture screws are, or into where the idle jet goes? or both and everywhere else? haha

[Bru-tom]

could my filter be letting too much air through?

[Deltarider]

How sure are you the jets have the correct opening? Could it be the jets are accidentally widened by rigourous cleaning using materials that are abrasive like iron? By you or the PO?

[Bru-tom]

im not. and also dont have access to more locally. where could i order some from? the decent ones?

[DustyRags]

Yeah, just turn the bike on and let it idle, and then flow the gas around the intake boots, etc, and listen for a rev increase.

For me, I cleaned my carbs by completely disassembling them and blasting carb cleaner through everything. WEAR GOGGLES! That stuff's vicious. My goggles have marks on them where I got carb cleaner on them and it melted the plastic. 

[CBcafeJunkie]

Having same issues but with all stock setup, only thing I can think of differently is my airbox doesn't have the seal in it. Is it a possible cause and where can I get another one?

[Bru-tom]

Yeah, just turn the bike on and let it idle, and then flow the gas around the intake boots, etc, and listen for a rev increase.

For me, I cleaned my carbs by completely disassembling them and blasting carb cleaner through everything. WEAR GOGGLES! That stuff's vicious. My goggles have marks on them where I got carb cleaner on them and it melted the plastic. 

i did that mate and the intake is leak free.

Since then, I did the same as what you did. stripped the carbs AGAIN, ran carb cleaner through every nook and cranny. Made sure i was getting stuff coming out the right places at the right time. i kinda understand how they work a lot better now. However, there didnt seem to be much if anything out of the ordinary that came out. But you never know until you test it once more.

My next question is, after a ton of research and reading, i should expect a richer mix due to my less restrictive 4-1 exhaust i have on the bike, I read that due to the faster airflow past the valves, it tends to pull more fuel from the carbs, can anyone confirm that?

Also, due to the pulse carbs design, a less restrictive intake could also cause rich mixture contrary to popular belief? But because there is no real effect between running with filter or without, its still rich and blubbery at under 1/4 throttle just off idle.

Other than that, i am in the process of ordering Honda rebuild kits, then once that is done (suspecting slow jet is worn or tampered with as everything is perfect around that, namely float heights and air screws are almost on their last threads before falling out) i can eliminate any questions about the possible faulty components inside the carbs.

[K3Owner]

I browsed through this whole thread and you said that turning off the fuel got rid of the problem so a lowering of fuel in the bowls made it right. After that, we see that the angle of the carbs is 'off'. Not a big deal one would think but did you check that there is no leakage by the float valves (seems OK with new o-rings)? Did you, for giggles, lower the float height a few millimeters to see if it cleared?

I know, a stretch, but there is definitely dramatic flow to make it chuff black smoke. My old 78 Kawi used to do this - cleaned jets and float valve and all - it was a sticky float so I carried a screwdriver and whacked it when it did this - had no money back then.

All part of the fun of owning a years young bike.

[Bru-tom]

thanks for the heads-up mate. I have actually started looking at that. Seems that my idle jets are not all 100% the same height, and as far as i know, the float height it the same as the idle jet (i read that somewhere).

Second to that, a mate of mine borrowed me his identical carbs to try, his bike runs fine and even with pods. I, out of curiosity, open his float bowls up and saw that they were all out of whack! i mean one was at nearly 30mm and others at under 20. so i have no idea how they can work?!

do i adjust them before i fit them to my bike to try, or leave em be?

[Deltarider]

The importance of a correct float level is often overestimated IMO. On my CB500 after a stop I sometimes forget to re-open the petcock and I am always amazed how far and long the engine pulls just as fine. It takes a considerable stretch or time before it starts complaining and it's not right away after it has finished the gaz in the fuel tubes.
That's why I've advised (many times now) to refrain from bending the floats. Chances are little a PO has ever messed with them (unless it is a reader of this forum).
Then this. In many manuals (Clymer, Haynes, you name it) almost every possible maintenance is described. Ofcoures the authors fill their books with everything imaginible. So you, after the purchase, have this satisfying feeling the book is of great value. But... it doesn't mean you have to actually do all these things with your bike. Before you start adjusting, always ask yourself how likely it is something is wrong.
An old and experienced mechanic that has worked a lot with these bikes, can be a good source of information. He can tell you this particular bike has always problems with this and that particular bike has never problems with it. The books are academic and describe everything possible regardless of the likeliness.

[K3Owner]

I guess if you're making a comparison to his bike's running condition, you should change nothing so it's apples-apples, as they say.

[Bru-tom]

Thanks Delta! I totally agree with you! Its a guideline more than anything...

Well, Turns out the float needle's spring are worn and soft. So the stock 22mm is letting more fuel in than the "spec" says it should. I found this out because, on my mates set of carbs, i had to order a new needle and seat for him as his was a mismatched one that the PO slapped in there. and its much stiffer than the old ones. So i set the new one on 22mm and left the old needle's floats on 25mm. There is absolutely a huge difference in performance low down compared to before. There is 95% better performance! i am so happy. There is little top end, but thats due to damn pods.

My next step is to redo my own carbs float levels to that of a higher one, and slap them back on and see if thats corrected my previous issue i was having with them. Obviously revert back to my custom/stock plenum and see how she runs then, but so far i am a happy chappy!

[Bru-tom]

I guess if you're making a comparison to his bike's running condition, you should change nothing so it's apples-apples, as they say.

Yep, and as you can read above, a major improvement! Thanks so much for that random well timed post Sir

[K3Owner]

Excellent - sounds like you're on the right path!