Starved?

[gearhead13]

I really dont think a pingel is needed here, I have the stock petcock on a built 750 with 34mm mikunis and have no problems, maybe when i stuff the 1100 in I could have problems, but I *think* the 1100 and 750 petcocks are the same, arent they?

 

[almarconi]

Did you check for air leaks?

Sounds like its running lean on the mains. Did you check your fuel height (in the carb bowls)? It's possible your fuel height is too low.

What do your plugs look like?

 

[KitKat]

i had this same problem when i bought my bike. it would accelerate up to a point, then it wouldn't around a certain speed.

i replaced the petcock with OEM
cleaned carbs
... almost everything mechanical

what it turned out to be was the r/r. Mine did something funky: when it wouldn't further accelerate, i turned a turnsignal on, and the engine would suddenly pulse with immense power at the time the signal was flashing. so then i took out one turn signal bulb: which makes the turn signals stay on constantly, which gave me constant power throughout. Also had a similar effect when using high beam.

got a honda r/r from duanage and now perfect. might want to test your r/r

 

[gearhead13]

did you clean (dip) the carbs and put new o-rings in them when you put in the dj kit?
Take a look at your plugs, take a pic and/or note different colors, especially #2.
I noticed that those arent K&N pods, the dj kit is tuned for K&N pods AFAIK. You might need a richer or leaner main.

 

[GavinJuice]

at 60MPH he's barely running on any main jet, this is all needle and pilot in play here and further there is no mention of any WOT where main is found.

on a VV carb you could easily choke it to see if you're rich or lean at the speed you talk about, but a CV i don't know if there's enough signal for the fuel enrichment?

 

[jonmasaya]

Carbs were cleaned immaculately by the P.O. O-Rings were in pretty good shape. Choke had little to no effect at 60mph, but will try again.

I ordered a new petcock. In the meantime I'll take the carbs back apart and check everything, along with the plugs. I might try a different needle position as well.

Thanks everyone for your help so far!

 

[jonmasaya]

Update: Installed new petcock. It definitely fixed part of the problem, it no longer starves out and runs quite a bit smoother. However, it still stumbles and hesitates a bit at high speed. I just noticed that the Mac exhausts have a similar back pressure to stock, so I'm probably running too rich with the 130 mains. I'm going to switch to the 124s and see if that helps.

 

[Guest]

Update: Installed new petcock. It definitely fixed part of the problem, it no longer starves out and runs quite a bit smoother. However, it still stumbles and hesitates a bit at high speed. I just noticed that the Mac exhausts have a similar back pressure to stock, so I'm probably running too rich with the 130 mains. I'm going to switch to the 124s and see if that helps.

Check the spark plugs. Reading them will tell you if you are rich.

 

[Steve]

I just noticed that the Mac exhausts have a similar back pressure to stock, ...

Please tell me: how are you measuring the backpressure? :-k

.

 

[Guest]

Please tell me: how are you measuring the backpressure? :-k

.

He puts his hand over the can? :hand:

 

[jonmasaya]

Haha. I didn't measure the backpressure, just remember reading it somewhere.
I also had a hunch it was rich when my eyes started to sting. lol.

Anyways, I put in the 124s and now everything runs perfect!! I just got back from a nice cruise on the freeway at 70-80mph. =D

 

[Kcwiro]

Well you got some guts riding in the weather we have had.. need a new helmet, boots and gloves before this spring. I work graveyards so I do not see the sun much these days ...least what we call sun in seattle

Good to hear you got it sorted out though

 

[jonmasaya]

Well you got some guts riding in the weather we have had.. need a new helmet, boots and gloves before this spring. I work graveyards so I do not see the sun much these days ...least what we call sun in seattle

Good to hear you got it sorted out though

Hey, If you don't ride in crappy weather in Seattle... you won't get to ride at all! I prefer riding at night too, there's less cars on the road to watch out for.

 

[jonmasaya]

Another update, in the hopes that it may aid someone else. I just moved the clip on my needles down a notch (towards the pointy end) and I no longer get any more bogging down at any point in the throttle. Runs grrreat!

Recap:
-mac 4-1 canister exhaust
-cheapo pod filters
-dynojet stage 3 kit
-new petcock valve

carb settings:
+clip on second notch from pointy-end of needle
+124 main jets
+1.5 turns out on air screws

 

[Guest]

Another update, in the hopes that it may aid someone else. I just moved the clip on my needles down a notch (towards the pointy end) and I no longer get any more bogging down at any point in the throttle. Runs grrreat!

Recap:
-mac 4-1 canister exhaust
-cheapo pod filters
-dynojet stage 3 kit
-new petcock valve

carb settings:
+clip on second notch from pointy-end of needle
+124 main jets
+1.5 turns out on air screws

Thanks for the update. :clap:

 

[Steve]

What jets and which notch on the needle did you use?

I used the 130 jets in the kit. Clip is on the 4th notch from the top with two washers below it. Was considering lowering the needle...

Why the washers under the clip?

The washers keep the needle a little higher I believe.

They don't. They just add a little spring pressure. Since the needle is pushed up into place by the spring, the height of the needle is determined by the clip and what's above it.

Update: Installed new petcock. It definitely fixed part of the problem, it no longer starves out and runs quite a bit smoother. However, it still stumbles and hesitates a bit at high speed. ... I'm probably running too rich with the 130 mains. I'm going to switch to the 124s and see if that helps.

I put in the 124s and now everything runs perfect!! I just got back from a nice cruise on the freeway at 70-80mph.

Another update, in the hopes that it may aid someone else. I just moved the clip on my needles down a notch (towards the pointy end) and I no longer get any more bogging down at any point in the throttle. Runs grrreat!

Recap:
-mac 4-1 canister exhaust
-cheapo pod filters
-dynojet stage 3 kit
-new petcock valve

carb settings:
+clip on second notch from pointy-end of needle
+124 main jets
+1.5 turns out on air screws

So, in summary, you leaned out the upper end with the 124 main jets (those are DJ numbers, right?) and richened up the mid range a bit by lowering the clip, which raises the needle. Did you tweak the "air screws" (they are really "idle mixture adjustment screws") for highest idle speed or just set them and forget them?

Had you read the plugs in any of this process? Doing plug chops to read the color of the plugs would have told you what the engine is doing, might have saved a bunch of time and aggravation. :-k

.