1982 Interstate

[slabghost]

Motor sounding like hell is probably a combination of over rich carb and ignition timing. Are all the vac ports plugged vacuum line to ignition hooked up to baseplate vac port?

 

[dan filipi]

Have you checked the basics like compression and getting spark at all the plugs?
A fresh set of plugs may be in order.

 

[joedrum]

well it is good to ck belt timing and tension of belts ...take all the plugs out and ck compression if you have gauges .....then go back after it ...is your throttle plate hole open or closed on the carb ...get all the info posted ....hmmm wonder how dkl throttle plate hole is on his ....if there no leaks this carb should dial in .....

 

[wedoo2]

I have been working on the bike this morning and still have not figured out the idle. I did pull the plugs and they are pretty black so I imagine that I am running rich. There is good spark on all four. I think that the problem with the idle lies in the adjustment on the fast idle lever as I am setting both the volume and bypass screws at 2 1/2 out to start with. I am following the instructions that I found here. https://www.66bug.com/Tech/Solex34Pict3.html. And here https://www.vw-resource.com/34pict3.html

There are two vacuum ports and one is plugged and I am using the other for the ignition. I will check compression this evening. that should tell me if the knocking I am hearing is something bad.

The acceleration on this when I pull it is very responsive although I detect a miss even over 5-6 grand. You're right Joedrum this should not be that hard. I do not do this so that is probably most of the problem. If I can't get the idle to stay, and my compression is okay I may just slap the old carbs back on it. Try to bench sync them as best as possible then get it over to my bud to sync with gauges. then come back to this later. I already have everything.

 

[joedrum]

ok if its running rich .....id say there is no leaks in manifold...so thats good ....seems it must be rich at the higher rpm as its not idling much ....hmmmm dkl said something about adjust choke right ...id say this id probably the key here ...obviously it needs more air ....also if it was me id open up the throttle plate hole if its closed now .....and any air adjustments it might have on carb need to be open ...carb is not that hard to learn hang in there ..ive seen to many work good ....id say it all carb adjusting

 

[dan filipi]

If I remember you had the same problem with the stock carbs which suggests to me the problem is something besides carburation.
You said it seems to be missing at higher rpm also so I'd throw in a fresh set of plugs even though they seem to spark ok. Under load they may not be.
I had a similar problem and fresh plugs made a big difference.

 

[Denver]

Try a vacuum gauge on that or any vacuum source, :yes: should hold around 14 in of steady vacuum on any healthy motor in my experience. :headscratch:

 

[wedoo2]

I just checked the compression and I have problems on the right side and that is the side I adjusted which was my first attempt at that. My buddy the old Honda mechanic did the left side and we were doing it outside when it was cold. I had just changed the head on that side so we didn't look at the right that evening. Here are the numbers:

1. 32
2 120
3 102
4. 120

I guess that might cause a little uneven running huh? I'm going to call Motorcycle Bob and let him adjust the left side and look at the carb as well. Get his input. Denver, I don't have a vacuum gauge but I need one anyway so at some point I will get one this week and make sure that the carb pulls enough vacuum to run the ignition.

 

[joedrum]

ok ...you know throttle has to be open to get good reading ...the 32 reading on number 1 is alarming ...something big is going on there ...

 

[slabghost]

for a reading of 32 it has to have a valve that doesn't close. Adjusted too tightly will cause that.

 

[wedoo2]

joedrum » 35 minutes ago[/url]":3vw44396]
ok ...you know throttle has to be open to get good reading ...the 32 reading on number 1 is alarming ...something big is going on there ...

I am alarmed. One nice thing about it is I have two more right side heads from my two previous motors. Rods, pistons, rings scare me, but not heads. Bent valves....I laugh at the thought. I think that I just suck at adjusting them.

 

[dan filipi]

Careful accurate adjustment to the valves first then check compression again.
Once compression is brought up even it should run very different.

 

[dkl]

My carbs are all stock, you must adjust the electric choke by the book, that will take care of the fast idle lever. The fast idle lever is not where you adjust the idle. Idle is set using the larger of the two screw. Must have air filter on to get it right. If you have no manifold leaks it should dial in reasonably well, the small screw should be between 2 or 3 turns out,,,,,,, but I have decent compression, and my vacuum is working.
Set the idle anywhere between 1200 and 2000. You can bring it down later after you get it dialed in.

 

[Denver]

Vacuum gauge is just a quick & dirty way to tell the general, over all shape of the motor, without any disassembly. :yes:

 

[slabghost]

Denver » Mon Mar 28, 2016 7:37 pm[/url]":j3qc1fqw]
Vacuum gauge is just a quick & dirty way to tell the general, over all shape of the motor, without any disassembly. :yes:

There are many other uses for vac gauge. 14" is about right for a healthy motor if measured plenum @ idle. Closer to the valves you will get fluctuation.

 

[Denver]

True enough, but for now, just the knowledge of one of the more basic uses, is the point made. :thank_you: No need to tell a guy how to build a watch, when he only asked the time. :hihihi:

 

[dan filipi]

I normally get 9-12" vacuum at idle on the single carb. When I would sync the stock rack, it read about 9. Two gauges I have say anything below 17" is late ignition timing, which isn't the case that I've checked because I've programmed in different ignition timing into the C5 resulting in little if any increase in vacuum. My conclusion is vac reading on these engines don't tell us much.

 

[Denver]

Steady pull of vac is a quick check, :roll: & indicates a healthy motor as far as even normal wear. :thank_you: More compression creates more vacuum, :yes: less compression, less vacuum. :doh:

 

[joedrum]

if you were talking stock horns ...and you checked vac there ...it could be a measure of that cylinder condition ...just like compression test dose ...but it would have to be ck there to be any good at all .....

 

[Denver]

Differences in compression make vacuum gauge bounce around. :thank_you: Like i said a quick way to tell the over all condition of any like type of motor, :yes: say to see if worth buying. :smilie_happy: