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Discussion Starter · #1 ·
Big shout out to dugans, a new Twins member whom was awesome enough to visit on Sunday to lend two hands to my 450.
This group is really something special and the kindness of above reaffirms it. Though my damn ride is still not 100% sorted the fact that someone made a trip to at least get me closer means a lot.

cheers to all! let's keep it going!
 

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Good job, Dugans - when you think about the 21,000+ members here totaling all Honda Twins enthusiasts who know of this place from all over the world... it's a small society of like-minded people who willingly share information and help. You just can't get any better than that, and I'm glad I found the place when I did (and wish I'd found it sooner). :D
 

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Discussion Starter · #5 ·
thanks everyone!
and....here is where we stopped at: both points open when they should, bike is still a pain to start, both mufflers get warm, bike dies when revved. despite a near-perfect (?) carb synch. it is still not good to go. Gonna replace the left point now and see. bowls show near equal amounts of fuel when drained. Valves were set correctly before and I don't see anything indicative of issues there; It doesn't struggle to make power when revved or make abnormal ticking sounds.


This is the most trouble I have had with it, barring the big oh no thread of course ;) cheers....ugh...
 

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I have not been following your posts to know what's been going on with your bike. Maybe it would help me and others if you can summarize what you have done so far on the bike.

1. Are you running stock air box and exhaust?
2. Are you getting consistent and strong spark from both spark plugs?
3. Did you rebuilt the carbs? With a kit? What kit if so?
4. Have you checked for compression?
5. How do your plugs look?
6. Have you checked for a vacuum leak around the carbs and intake?
 

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Discussion Starter · #7 ·
@76twin

stovk boxes and exhaust, strong spark due to updated coils years back, genuine Honda jets, 155 psi cold compression, plugs looked sooty but that is due to all the hard starting and revving. New set of plugs looked ok. I did not notice any vacuum leaks. This is very frustrating. Charging system works and battery reads 12.6 volts once charged. I did everything I know how to do and still no results yet. Thoughts?
 

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Only 3 reasons why an engine won't start

1. no fuel
2. no fire (spark)
3. mechanical interference


Since you stated that the ignition timing is spot on and sparks are strong , that pretty much leaves fuel being the culprit.
You rebuilt the carbs right? Did they pass the straw test?.
 

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It's all about the bikes.

One thing I saw that I didn't like was the front set of points.
Most of my experience is with sohc cb 750s but that set of points would have stopped me in my tracks.

Both cyls were running by the time I left but the left side came in first and after some revs the right side would kick in.

I am pretty much a n00b when it comes to these bikes but my steps would be the points, check valves and then pull the carbs for inspection.

Of course I still think you may have a Honda-hating poltergeist....
My 750 only gave me that much of a hard time starting when the carbs were royally messed up.
;)
 

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and some more distracting listings of machines currently running better than mine ;)

1975 Honda CB
Interesting bike, decently done but $10k? not me... and I'm puzzled by the choice of a Kerker 4-1 with someone else's muffler/megaphone on it. Kerker was as good as it got for inline 4 cylinders back when that bike was sold, I had quite a few and they worked really well on all of mine so equipped
 

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Sorry for a slightly longer post, but here goes. I had pod filters on mine, the kind that don't block the air jets, so had increased the main jets to 150, then 155; it ran OK, but still had issues over parts of the rpm range. When the OEM style replacements showed up, I grabbed a set, and a pair of jet kits that include a selection of mains and needles to match, new needle jets and pilot jets; didn't use the pilot jets, but did the needle jets, just in case they were worn. I dropped the mains to 149 with the matching needles, and it was still hard to start, enough that I used one of those booster batteries on 'cooler' mornings (<80F). After a tankful, I pulled the plugs, and both were covered with soot. So I put in the stock size 145 mains and matching needles from the kit; it started right up, and the plugs are getting clean! Bottom line: too rich will make this engine harder to start, too. I haven't needed the booster battery since; of course, it's been rather warm, which helps, too.

To set the floats, I use a float gauge I made from a bit of sheet aluminum, from the photo in the manual, and hold the floats up with it, then turn the petcock on. If the fuel just weeps past the float valve, I'm happy with the adjustment. Any more than just wetting the valve, and I adjust it; no wetting, and I ease the gauge down to see how far it takes to get fuel to flow, and adjust if it's more than a few hairs.
 

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To set the floats, I use a float gauge I made from a bit of sheet aluminum, from the photo in the manual, and hold the floats up with it, then turn the petcock on. If the fuel just weeps past the float valve, I'm happy with the adjustment. Any more than just wetting the valve, and I adjust it; no wetting, and I ease the gauge down to see how far it takes to get fuel to flow, and adjust if it's more than a few hairs.
I like that trick!
I guess If the timing is close and the valves are fully closing, there should be sufficient vacuum to pull gas and ignite it.....if the throttle plates are closed enough to create that vacuum.
 

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Discussion Starter · #15 ·
I'm going to load test my battery today just to be sure. I know it charges right up and reads 12.6 but it is over 3 years old and we all know the questionable lifespan of bike batteries.
From there I will reconfirm float heights and clean out the jets. I run 135 mains which I have kept since it ran flawlessly those 2 years(2 seasons) with those. I know manuals stated my model carbs can go 140-145 which I tried but it did not run nearly as well.
as Dugans stated, the carb sync is much better but it's still hard to even adjust idle speeds on a bike that....doesn't idle!
 

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Discussion Starter · #16 ·
so....Load tested battery and confirmed it was fine. I will replace next year as that is 4 years and these things don't seem to last much longer than that.
Once again, I got nothing today! I changed the left point to a brand new Honda. Static timed to confirm what we did last week was correct; Right side is good which always is a pain for me and the right pipe is nice & hot. Left side? Luke warm and that's it. It got to the point that it was still a bitch to start and still no idle. This is going on 3 months with not a single test ride or even an idle.

When static timing the left side the bulb never went on at any time but on LF during compression stroke the point was just opening and the gap was within the proper measurement.
I am stumped. I already did everything I know how to do. Hard to fiddle with any idle speed settings as the thing just won't idle. I left the carb. sync alone as we got that very close.
 

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Discussion Starter · #18 ·
This is the same ride in my the big oh no? Thread, fixed by my now ex-pal. Screw was discovered in combustion chamber and resulted in one bad valve, all other critical parts checked out ok.

iam not experiencing anything indicative of valve issues' no extra loud ticks or the bike struggling to rev when pushed, which would mean valves are set too tight. The carbs have nearly equal amounts of fuel pour out when bowls are drained. I forgot to add, the left side pipe had wet, black carbon residue when I put my fingers inside. I'm not too worried about that because there is bound to be build up from all the hard starts, revs, and bike dying afterward. Plugs do look good, though. This is the worst time I have ever had with it and I don't know where to go....yes, spark on both sides, coils, caps and wires upgraded and replaced 3.5 years ago.
 

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Discussion Starter · #20 ·
ugh, just recalled both valve covers seem to have an abundance of that white gunk Hondabond sealant he smeared on them! meaning, safe removal of them will be a big problem. I almost cracked my stator cover because of this; Successfully rectified that hairline crack.

I don't know how to successfully cam time and if they prove to be off isn't that motor out and cam removal? and valves & I never got along. I think I only did it correctly once. all other times were done by the one shop I used to go to and.....him.
 
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