Carbs and coils

[BruKen]

First run on the steamer today. She is fantastic. Soo smooth and effortless. I really like her. Two snags tho......


Is a symptom of coil breakdown when the engine at sub 3k rpm, constant throttle, but loaded (i.e. going up a steep hill in first behind a OAP who doesnt want to run over the sheep sunning themselves in the middle of the road) starts missing and bogging down. All other times she is as right as rain.

Carb emulsion tubes (and I checked and tuned carbs, float levels etc)............16 litres of fuel for 86 miles....... F********me! Runs like a steam strain, motor is wonderful except that bogging down. Bike is really smooth etc. Maybe I just had an air lock or miscalculated when I filled her up the first time......... I hope so....16 litres of fuel for 86 miles.........F********me!

No, I'm not a speed queen. Well, only a little bit.

[rf9rider]

Works out around 30 to the gallon?

Not too shabby for a rebuilt motor  :lol:

Don`t know what the average for these are, around 35?

[BruKen]

What? No can't be. I'd expect about 6 - 8 litre max to make 86 miles. This bike is 2-3 times over that. As I said I may have not properly filled the tank the first time round but she is definitely a bit rich. No biggie tho, emulsion tubes jets and needles are an easy fix. The coil replacements gonna hurt me though. I have already overspent on her and am trying to squirrel away some extra dosh for the Sept trip. I am right in suspecting coils....aren't I? Mmmmm

[rf9rider]

Cheaper alternative for the coils (if they are suspect) would be a secondhand set of TT600 coils, got them on mine with no problem.

[Mustang]

it could be the excessive rich mix causing the bog at low speed

are the coils marked PVL or GILL  the gill coils suck balls the PVL's are what nology's are just rebranded with a sticker

where you are using that much fuel for 80 miles I would suspect carbs
did you put new orings on the float assemblys assuming that they are Mikunis ?

[NeilD]

yeah sounds same symptons as coils on my Thunderbird Sport... I tried testing them as per the haynes manual but couldnt get sensible readings on the multlimeter, so just bit the bullet and bought 3  :shock:
MPG should be better than that - mine does 45-50 MPG, although drops a bit if having a thrash...  

[GavD]

Rf9's calculator must be dodgy. Works out at just over 24mpg, should get nearer 40.

[BruKen]

it could be the excessive rich mix causing the bog at low speed

are the coils marked PVL or GILL  the gill coils suck balls the PVL's are what nology's are just rebranded with a sticker

where you are using that much fuel for 80 miles I would suspect carbs
did you put new orings on the float assemblys assuming that they are Mikunis ?

I'll have another look. I think they were PVL. I looked at the o-rings and they were good so I didn't replace. Time is against me now for the Sept. Tour so I will replace those as insurance along with jets and tubes. Its replacing the coils that bother me. I can go for the TT600 but as money is tight I don't want to waste it unneccessarily.

[Mustang]

pvl's are the good coils  :D

[GavD]

I got a set of TT600 coils off ebay for £40 and spent about £5 to extend the leads (all spade connectors from maplins).

I then thickened up the coil to fit the hole using heatshrink tube.

Had no problems with them.

You just gotta make sure you get the right type as some have a large top to them that won't fit.

[rf9rider]

Rf9's calculator must be dodgy. Works out at just over 24mpg, should get nearer 40.

 :lol:  :lol:  :lol:

Late night plus beer = shouldn`t do rough calculations in my head

[BruKen]

Well my coils are PVL so I knew it had to be the float assembly O-rings. Sparkplugs 1 showed rich and 2 was a coal field. 3 was perfect.

So for the 6th time this last month I whipped (ha ha ha splutter) the carbs out, took the float bowls off, tipped the carbs upside down and blew with all my might. Not a leak. Sucked. Not a leak. 1 bar air pressure, not a leak.

..... Oh fek, :( choke sealing? Yep :(

Mmmmmm


So I started to strip carb 2 and immediately saw the problem. At some point during reassembly the needle to spring bush must have fallen out unnoticed. This allowed the circlip to slowly wind its way up the spring like a worm screw constantly richenning the mixture.

This time putting the carbs back in was a nightmare. Why this time I have no idea, but it took two hours.

The bike has lost it's sub3k bog down under load and is even more reposnsive. I think, touch wood, that's it. Proof rides are now all acceptably good :) .... No, brilliant :D

Oh carb 1's pilot needle was 4 turns out, put it to 1.5

[Mustang]

[rf9rider]

2 lots of applause from Mustang?

You must have done very well.  :lol:  :lol:  :lol:

Good to see its sorted, enjoyed reading the rebuild.

Its given me the inspiration to start on my "special"

Took a few bits to the powdercoaters.  8)

[Mustang]

2 lots of applause from Mustang?

You must have done very well.  :lol:  :lol:  :lol:

:oops: fat fingers ????