Having some throttle issues.

[sikewrdpryznr]

I finally got the rights to post

Anyways. I just got my first bike, it's a 1986 Honda Shadow VT700C. It's a decent looking bike, with just a few cosmetic issues.

The thing I'm having trouble with, and by trouble I mean it's an issue that I'm looking for some advice on before I just tear it apart. The bike starts ok, and it will idle just fine, and it will even drive decently. But the issue at hand is that when you give it throttle, you have to baby it, otherwise it acts like the butterfly is shut. Now given that the issues aren't when starting or idling, I'm wondering if anyone has some insight? I mean it'll accelerate, but if you try to give it too much gas, it acts like it's starved.

I've worked on cars before but this is my first bike and I don't want to ruin anything. I didn't pay much for the bike(a whopping $650) and it has a little title issue which will be about half the cost of the bike to get sorted out but it's not a big problem.

Any help will be much appreciated Thanks a lot and happy riding.

[dernp]

It's sounds as if you are in for a good carb cleaning, especially the main jets.

Edit: Did you try and run some Seafoam through it?

[rieckena]

^^^^ what he said, Seafoam is our best friend

[sikewrdpryznr]

Originally Posted by dernp

It's sounds as if you are in for a good carb cleaning, especially the main jets.

Edit: Did you try and run some Seafoam through it?

Well I haven't gotten to ride it much, just got it and there's an issue with the title and I don't have the money to pay for a bonded title just yet. So I did buy some seafoam and put in the tank, and a little in the oil. Me and my dad ran it for a while while sitting still and hadn't seen any improvement yet.

Also, we thought we had the issue pinned down when we checked the choke and it didn't do anything. We checked the choke pistons and one of the springs were mangled beyond recognition. Without the choke attached and with a finger covering each hole, the throttle acted like normal. I went to the hardware store(because the nearest bike shop was 40 mins away) and found a couple of springs that were the same size but a quarter inch longer or so. Installed the new spring on the side that was messed up and it's back to having issues.

It will accelerate like normal if you just ease on the throttle, but then you get to a point in the twist and it boggs down but doesn't quite die.

Again, thanks for the information, I have found the book of all knowlege but it didn't address this specific issue. We were going to tear into the carb sometime this week but thought I'd see if any of you guru's had any ideas that would keep the trial and error to a minimum

[GrumpyOldMan]

Also, if you decide to do the whole carb teardown and cleaning, it might be a good idea to bump the jet sizes a bit - check out the Fuelology sticky.
These bikes, especially the 80s ones, are setup very lean so anything that causes even the slightest restriction in the jets will make it hard to start and hard to run. If if starts OK and runs OK at idle, then it is likely the needle and needle jet that is a bit dirty. The main jet mostly affects top end.

[gordo2472003]

I Had the same issue a month ago when I got my vt700 . buy a carb rebuild kit clean the carbs and run some sea foam through the gas. Worked like a charm!

[John Hopkins]

When you strip the carb don't forget to strip the air cutoff valve..don't lose the spring..check the diaphragm and don't lose the washer in the pilot jet.

It's no good having a spotlessly clean carb if you have pinholes or splits in the diaphragms.

John.

[sikewrdpryznr]

Hey thanks for the tips fellas, I'll be tearing it down either tomorrow morning or maybe thursday.

[CavemanBen]

also make sure u have no vacuume leaks between the carbs ad air filter. if the airbox has a drip tube make sure its capped. my bike acted like this but worse just because i didnt have the chrome cap over the air filter

[DaJesus]

If your problem persists after you clean out the carbs you might want to check the fuel pump. Mine recently went out and I kept having a deadspot around 2.5k and a lag in throttle response. Once the fuel pump was replaced it ran like a beast again.