[greendub]

I have an 87 tw. Exhaust, wiseco 1mm high compression and big gun. Bike developed a miss at top end and a intermittent miss during idle. Head is rebuilt with new valves and seals. Trying to diagnose. The carb is clean with a 124 main on the old style. Thinking about buying a new carb because mine is beat up. I have replaced a lot of parts in it, but think new is the way to go on a bike this old. I have a throttle/switch assembly for a newer tw and the cv carb costs less new than the slide. Any thoughts on new or old style carb. I am hoping my problems are related to the cdi which i am going to replace.

 

[Hoogie514]

When my 1987 started to miss at idle it turned out to be the CDI unit.

 

[lizrdbrth]

Did it develop the miss before or after you went 8 steps up on the main jet?

 

[Stromper]

Should at least do a classic plug visual examination



I was still enamored with the idea of going to a bigger carb



Saw some on fleabay for like $30



If you have flow work done then carb is/may be too small anyway.

 

[greendub]

Did it develop the miss before or after you went 8 steps up on the main jet?

Way after. Started working up from 118. After i installed the exhaust i went up until I was a little rich. Bike ran perfectly for a month or so. Also running really hot on header. Noticed the same on a friends 87 when his cdi went.

 

[greendub]

Should at least do a classic plug visual examination



I was still enamored with the idea of going to a bigger carb



Saw some on fleabay for like $30



If you have flow work done then carb is/may be too small anyway.

My plug shows rich. I think i am getting plenty of gas. Wondering if i would see a difference riding it with a cv tw carb jetted and adjusted correctly.

 

[lizrdbrth]

Were it not an '87 there wouldn't be that sniggling fear of CDI failure.



I'd check the miss against a timing light first, then proceed as per usual.



If it ran fine before, something has changed.

 

[greendub]

Were it not an '87 there wouldn't be that sniggling fear of CDI failure.



I'd check the miss against a timing light first, then proceed as per usual.



If it ran fine before, something has changed.

I'll check timing. Pulser coil mabye? Anyone have an opinion on the carbs?

 

[pgilles]

I have an 87 tw. Exhaust, wiseco 1mm high compression and big gun. Bike developed a miss at top end and a intermittent miss during idle. Head is rebuilt with new valves and seals. Trying to diagnose. The carb is clean with a 124 main on the old style. Thinking about buying a new carb because mine is beat up. I have replaced a lot of parts in it, but think new is the way to go on a bike this old. I have a throttle/switch assembly for a newer tw and the cv carb costs less new than the slide. Any thoughts on new or old style carb. I am hoping my problems are related to the cdi which i am going to replace.

If you're going to replace the CDI, then just replace it and go from there.

Way after. Started working up from 118. After i installed the exhaust i went up until I was a little rich. Bike ran perfectly for a month or so. Also running really hot on header. Noticed the same on a friends 87 when his cdi went.

If the miss started happening way after then chances are it wasn't a screw-up in the initial carb cleaning. Doesn't mean something didn't work itself loose later on, but if there was no miss right after the carb was cleaned then I wouldn't suspect it at fault. These carbs are pretty nuts and bolts. Install the jets, set float height, set pilot screw, adjust idle speed and you'll be in the ball park. Just because all the parts have been replaced doesn't mean it's bad.

 

[greendub]

If you're going to replace the CDI, then just replace it and go from there.









If the miss started happening way after then chances are it wasn't a screw-up in the initial carb cleaning. Doesn't mean something didn't work itself loose later on, but if there was no miss right after the carb was cleaned then I wouldn't suspect it at fault. These carbs are pretty nuts and bolts. Install the jets, set float height, set pilot screw, adjust idle speed and you'll be in the ball park. Just because all the parts have been replaced doesn't mean it's bad.

Ive been through the carb more times than i can remember. The float pin is loose, but stays in, Just worn out. New will be nice.