GregT
Hero member
- Location
- Christchurch NZ
redax5 said:
That's my experience too...I call the symptom, "gulp lean" - self explanatory really. No shot of fuel to go with the sudden slide lift = lean condition till the fuel catches up.
All cable operated flat slides exhibit this because there's no slide cutaway to moderate the air admission. You can jet Dellortos to run well without the pump but it's damm near impossible with flatslides.
Years back when the first flatslides appeared on GSXR's they had two pumps, connected to a log type manifold across all four carbs so you could run one, two, or no pumps. Naturally we experimented...Even though they were small pumps, changing made a noticeable difference. After much experiment we always ran both pumps.
There are thousands of pages of info about FCR accelerator pump modifications in the dirtbike world.You need instant responce at full throatal with them and what you get is either a bog from to much squirt or a bog from not enough.So thats why there are so many fixes.At least a couple a week before they bought in injection.That was supposed to fix everything,nope, then the ingestion fixes starting comming.
Been doing some fiddling on this.When i first got the bike going it was surging very slightly just above idle.That was fixed by lifting the needle 1 notch.Surging usualy indicats a lean issue.Got a good result with that.I had a cold fowling issue on start last weekend.Red supplys these carbs set at 3/4 of a turn out on the mix screws.I was surprised the plug came good after 3 or 4 ks but fowled again still at a traffic light for too bloody long,again it came good after 3 or 4 ks.We tried it at 1/2 a turn,that resulted in a reduction of smooth pull so its now between 1/2 and 3/4 of a turn out.I guess thats 5/8ths of a turn.It now has a solid clean sounding idle,havnt tried it but it starts well cold on choke and sounds good.Will try it over the weekend.Getting excited about what happens when it goes past 4k,feels like its going to be quick.