Tuning Question

OK if you have been following along I completely rebuilt my carbs this weekend. Surgically clean, all boots in great shape. When warm the engine idles at 1000 -1100 with no issues - smooth transition from idle up.

Now the question. When stone cold at half choke she starts right up and idles nice. But when you try to go it stumbles like not getting enough gas, with or without the choke on (need to be careful not to stall at stop with choke off). This is only the transition from idle to say 3k. Once you get about a mile down the road she runs perfectly fine.

I colortuned again last night to just take yellow out. Going to check the plugs when I get home tonight. Any suggestions? Thanks!

 

No suggestions? This is usually such a vocal group

 

sounds about right to me
i run 4th to the first stop, about a quarter mile and that seemed to take care of the problem

 

float height measure out okay when warm and cold? auto petcock taking a while to get the fuel flowing perhaps? does it do better if you let it warm up for a few minutes before taking off down the road?

 

I try to let it warm up for a minute or two but still the same. I'm going to try the petcock on prime as I leave work, I had a similar thought.

I think my float levels are good, they were on the bench at least. I plan to recheck on the bike. That was another question I had. Would a slightly low fuel level cause the issue? I can't see how but what do I know?

So Pollock I can see how a cold engine, properly tuned could behave this way, are you seeing the same kind of stumble? (best way I can describe it)

I can learn to let it warm up a bit.

 

i just think it's a "cold blooded" engine and after that first mile it runs fine
does this sound like yours, if as soon as it started you were to putt along at 2 or 2.5K in first it goes fine but the throttle must be rolled on very slowly or it just quits, let off throttle and it comes back
but if you nurse it up to say 3.5 or 4K and keep it up there as you shift it's ok, does that sound like it ?
the choke helps but it's still there
as it warms up the symptoms lessen then after a mile or so it's gone

 

Hmm more like it sputters till 2k to 3k then is fine and is great when hot. I'll have to try rolling the throttle slow - not in my nature...

I have not had any issues with quiting. I'm posting a plug read to see where I'm at with it.

Leaving work today (warm day near 90) I started it with no choke and turned the petcock to prime to test the fuel theory. Right after I started off (after a 30 sec or so warm up) I turned back to the normal position. Absolutely no issues, it was beautiful. I will repeat that experiment in the morning with a cooler temp and we may get the bottom of it.

I appreciate the good advice.

 

This morning I started her on prime with half choke. Sitting there was no hesitation from idle. Started off after about 1 minute warm up and shut the choke off before starting. Slight sputtering but reapplying the choke cleared it up which is way different from yesterday. After about 3/4 mile I had slight hesitation so turned off the choke and no more issues. Turned petcock back to on and drove the 15 miles to work no problem.

From my plugs I am slightly rich and I did lean a couple of cylinders (bad method changing multiple variable I know).

So I think this is being slightly to rich and possibly a lazy petcock (I saw that term in another post I like it). I'm going to concentrate on getting the tune right and play with starting out on prime until I narrow it down.

I'll post the results when I get it nailed down. I'm not trying to flood the forum but I hate finding a thread with my issue in it only to find no one ever posted the final answer!

Thanks to all once again for the great advice!

 

Further tuning and another sync resolved the hesitation issue. Once I got a lot closer to dialed in the problem disappeared.

 

If the tweak brought you closer to being Dialed-in ... stay with the Fine-tuning for a little longer.

It's cool enough in New England, now, that I give it a Full Enrichment to start it.
But, as soon as it starts ... I start inching-off the Choke.
After a brief warm-up ... she's ready to fight!

But, your Plug Chops will tell you where you stand as far as having the Mix right.
Now, when you MAKE TIME to inspect the Plugs ... the condition nthey are in will tell you how well your set-up and which hole(s) need a little more or a little less juice.

 

Agreed - I'm still at it. I pull the plugs a couple of times a week when riding everyday. Last week I did some more plug chops and synced again. I'm addicted Rick. I can't stop tweaking......

I just wanted to "close" this thread - I hate finding my exact problem and not seeing the conclusion.