Running rich and would like some advice

[Honda Al]

Maybe you should try airscrews two turns out and see what that does.

I started at two but the engine sounded a bit rough when accelerating. 1 + 3/4 seems to be better.

I'll keep you updated. :-)


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[deltarider]

That makes sense, all 500s and 550s with the oldstyle carbs need a relative fat idle for good pickup and driveability whilst accelerating.

[paulbaker1954]

Hi Al
I think you may have replied to my post on a similar issue. My 500 four was running very rich at low throttle and was a pig to get off the line

Eventually I bit the bullet and bought a set of carb service kits (jets, floats, needles etc) from Rusty riders in the US. But the main thing i did was borrow the ultrasonic cleaner from work and fully stripped and cleaned all the carbs. I found in the process that 3 Of the pilot air circuit circuits had been blocked and the cleaning cleared them fantastically


I have just got it all back together and it I'd running like a different bike.

I recommend you strip the carbs get them ultrasonically cleaned (you can buy a cleaner on fleabay for around £40. - you need a 3L tank) and change all the jets etc. It's quite a lot of work but well worth it in the end in my experience

[deltarider]

I don't need an ultrasonic device to clean the jets. They're easily removed, inspected and cleaned.

[deltarider]

Aren't the jets the smallest bores in the fuel system? After removing the jets a squirt of carbcleaner (brakecleaner) is usually all what it takes. But I'm open to new insights. BTW, I wonder if anybody ever cut a disposed carb open to see how and what runs inside. I myself don't have the tools but it'd be interesting.

[paulbaker1954]

When making sure your carbs are not blocked.............

This may be a bit hard to describe but i will try (I'd post a pic but my carbs are now back on the bike)

The jets of course should be clear as should the emulsion tubes  but as Oddjob says it is imperative that the holes in the carb body are also clear and some of these are VERY small bore. The pilot circuit especially has a massive impact on both smooth idle, pickup off the line up tp 1/4 or so throttle.

For the pilot/idle circuit there are  4 holes in total involved:-

1) There is a small hole on the side wall inside the bore of the carb at 90 degrees from the top if you are looking down the carb towards the engine side. It's  just after the choke, this joins up with....
2) The pilot jet hole that you screw the pilot jet in to and then this in turn is connected to.....
3) The idle airscrew hole (the one where the air adjustment screw goes on the carb body)

All these 3 holes above lead in to a chamber in the base of the carb which is where the air/fuel combines and the mixture then squirts out from

4) A really, really fine hole you will find on the bottom of the bore on the engine side. It's just in front of the throttle slide.

The best way to check if the pilot circuit is OK I found was to pucker up your lips over the air screw hole and cover the other 3 holes with various fingers and thumbs. If you then lift each finger/thumb one at  a time you should feel air blowing (It's a bit like playing a wind instrument and a bit fiddly but easy to do).

I found on my bike that there were blockages in these circuits that ultrasonic cleaning cleared really well.

If doing a rebuild its probably also worth doing a complete jet renewal, float, needle etc as you never know the history of the bike. I got a set of  4 complete rebuild kits from Rusty Riders in the USA via eBay for about £50 inc shipping. My only complaint was that one of the float valves would just not seat properly so I ended up using one of my original ones. On teh plus side these kits are significantly cheaper than NOS or DS etc...

Now it's all back together it peforms like a completely different bike, more power overall, fantastic pick up from standing.....I am amazed at the difference and at how bad it has been since my rebuild was finished.

I have spent months trying to get my bike right and my, now well learned, advice with 500 four carbs is if you are doing a rebuild it will save time, much effort and stress to fully ultrasonically clean the carbs and replace all jets etc. I learnt the hard way-there is no shortcut here when it comes to carbs !!


I hope this helps