Dead cylinder, has spark. Won't idle with choke off (carbs just cleaned).

1985 vf500f interceptor

Hey all! I'm new to the motorcycle world and just picked up an 85 vf500f interceptor as my first bike!

The issues with the bike are that it will not idle with the choke off, and the battery side front cylinder is dead (sprayed water on the exhaust headers). The bike's carbs were just cleaned well 2 weeks ago, it has fresh gas in her and brand new spark plugs. Thus ruling out the obvious pilot jet being clogged regarding the idle issue. The dead cylinder does get spark, I tested it. A theory is that the bike won't idle with the choke off because of the dead load of the dead cylinder?

Any ideas on what could be causing the dead cylinder if it is not a spark issue? Could this dead cylinder be causing the idle issue?

Thanks,

Joe

 

First double check that the cylinder in question is getting fuel, then do a compression test.

 

How do you check if the cylinder is getting fuel?

 

First check that the Bowl has fuel in it by opening the drain for that bowl, if it has fuel ,then take out the Plug for that cylinder & crank it over & see if you can smell fuel comming from the spark plug hole.

 

So even with the choke on one of the cylinders is getting no fuel, and none of them are getting fuel with the choke off? Hmm, sure sounds like clogged pilot jets and a clogged choke jet to me, plus maybe some clogged mixture screw ports.

Does anyone else want to bet $10 that the carbs are clogged? Squirrel?

 

Well I took the carbs apart and cleaned them to the best of my ability. It seems now I have 3 cylinders firing, but 1 still misses. The bike also idles on 1/4 choke, but not off choke. The dead cylinder is getting gas, float bowl has fuel. Also spark plug was wet with fuel when pulled.

Any other ideas? How do you set the mixture screw properly? Where is the choke jet in the carb?

 

http://vfrworld.com/forums/mechanics-garage/22449-cleaning-carbs.html

http://vfrworld.com/forums/1st-2nd-...tor-fuel-air-circuit-identification-porn.html

 

Do a compression check first. Simple fix if that is good.

 

Not many worse first bikes than a troublesome VF, especially for anyone not an experienced mechanic, and unless it's only a matter of eventually cleaning the carbs PROPPALY to get it running OK, there could be another one back on the market soon or another parts bike.

If riders just started reading up on those bikes here before jumping on a low-priced CL offering, they'd be educated about the potential pitfalls of VF ownership and be in the position to make an informed purchase.

Knowing just the minimum about potential issues, anyone who'd buy a VF500 without it passing a compression test first is throwing dice against poor odds.

The ONLY good VF500 buy is one you can ride home from the seller's place without problems, and ride again the next day.

 

Squirrel is being kinda shy--c'mon man tell us what you really think...