84 honda Aero w/ vm-20 carb, wont start.

[bob]

Hello again guys:) I seperated this from my other post on the aero.
I installed the Mikuni vm-20 carb on my scooter and it does not start, doesnt even try. Being 2 stroke ditzy I figured Id post.

First of all it was not a direct bolt on as was advertised, i streached the boot pretty far to get the spacer to seal, consequently I opened a slight gap in the air box, the air filter is sealed and tight to the carb. I know these are pretty sensitive to that kind of air flow issue.

I checked spark, kinda weak but its there.

I changed the spark plug and tryed again, didnt start so i pulled it and looked. The plug didnt appear wet, but i did smell a faint fuel odor. Again Im not sure how much fuel will tolerate on a 2 stroke so it may be all it needed to foul.

I tried pulling the choke, and not to see if the engine "poped" diffrently between it pulled and not. I really didnt notice a change?

Im really stumped, Im really not sure where to go from here so anyone with a better idea would be awesome:)

[Rebel]

have you tried priming it? As long as the plug is not wet I don't think it is getting flooded.
Is that spark any different than it was before?

I'd be concerned about a "stretched boot" it might rip and then you might have a hard time finding a replacement.

[jmkjr72]

personaly i would give it a shot of starting fluid to help prime everything up and get it to run for just a couple seconds on the starting fluid
as long as your oil injected this shouldnt be an issue

[bob]

Cool, thanks. I have some starting fluid too. I have to find a spot to spray it into, is leaving the air box open ok when I do that?

[jmkjr72]

yes
or if you can get to it you can spray in the intake hole on the air box

[bob]

Ok, sweet:) Gotter fired this morning but dont have time to tinker. I think the reason for it not starting is because is has a wot problem somewhere. I shot it with fluid and it just pegged. I used the stock throttle cable but it has plenty of slack to keep the piston from binding etc.
At least it runs, and ideas on the WOT issue?? I played with idle screw but is may still be in to much.

[Rebel]

Might have something stuck in the carb.

[bob]

I havent pulled it out yet, but I suspect the plastic spacer is cracked. I am going to need a new thicker one anyway to keep from stretching the boot. Is there a good place I can find new ones??

[bob]

told you I was rookie. "slide" carbs have a "idle" slot and a "cable slot. Please delete this one. Someone had a laugh..sad thing is I HAD a carb to look at. Sorry guys. It "looked like it went in". FIN..

[Rebel]

no laughing going on here.

[bob]

Ok:) carbs in, I rode it as much as I could, its miserable in Washington right now, it snowed today.
It works pretty good but the cable is a hair too short. Even with the jam nut on the underside of the cap. I am happy with that for sure, its a fun scooter.
I wanted to ask again if there is a good sourse for carb spacers? As the boot is still pretty strained.
Also, I have the carb running as good as its going to get with the stock jets etc...

Ill just describe it...Idle withe the new carb is way stronger..after I messed with it a bit the motor sounds like it "wants" to run, (note here, if I go one way or another it pings "tapping on a peice of tin?? not sure if thats good or not? ...The low end is pretty close to the stock carb as far as getting on it from a stop, little smoother.
Mid range ROCKs...
High...sucks. I bombed at forty five easy with the stock carb..new carb s\truggles at 40.. 42. I dont know whether to raise the needle or try jets..
Thanks guys:)

[jmkjr72]

where at in wa i graduated from central kitsap

if you have no issues say up to 2/3 or 3/4 throttle then its your main jet

if the issue is in that area it could be your needle

the needle plays the largest roll in the whole set up

[bob]

Right on:) you know how I feel. Im on the east side right now.



It seems like it lacks power kinda up to 2/3rds throttle, Not real worried, the engagement is way smoother. Im pretty sure thats normal.

2/3 rds to 3/4 is where is has all of the power, it pulls great till I go wide open, it dives pretty hard. I can do maybe 42. The stock did 45 and I hadnt even opened it up over that.

I will look into a main jet, see what I can find. Im also going to go for a pilot, only because the the air screw is run out pretty far to get rid of the "ping". If I go one way or the other it sounds like a bb running around a tin can.

[jmkjr72]

i would richen it up at the needle before messing with the main jets
so lower the clip on the needle 1 notch and see what happens
this might help the low end also

[bob]

I raised the needle one notch. The low end is great, wayy better, mid is "OK" high is still falling flat. Ive lost the snap from mid to high.

On a side note, Ive been able to use this cable up to now, it tried to stick this time. I need to find a cable but dont know how long this one is.