Tanto's New Redhead

[tanto]

Rick Oliver said, "Return everything to standard." Wise words. Here's what was lurking in the air-box.



Frankly, I'm impressed at the ingenuity of the Thai mechanics. When it comes to keeping an NC30 on the road, they've tried everything. The inside of the air-box was completely clean.



Needless to say, the Scotchbrite pads were replaced with some of Rick's foam, same for the sub-filter.

[tanto]

With the air-box done, it was time to dig a little deeper - the carbs. Here was to be the site of my most wrong-headed screw-up.

The first step was to clean the carbs, and ensure they were in standard specification. For a Japanese import, that means 116/118 jets, floats at the right height, and two turns out on the pilot jet adjustment screw.

Following 400GB's "NC30 carby jetting - DIY guide" written by Cammo, I removed the carbs from the bike. The tip to lever them off with a piece of wood worked very well. In short, I read through the instructions, thought I understood them, and re-assembled the carbs having:

• Changed the jets to 112/116 to account for the altitude and heat in Chiang Mai.
• Checked'n'cleaned emulsion tubes
• Checked'n'cleaned pilot jet

A set of Rick Oliver's float bowl gaskets and stainless steel screws sealed the float bowl covers properly.

It was at this stage I failed to notice a newbie mistake. I had mis-read the instructions and confused the pilot jet with the pilot jet screw. Thinking the pilot jet, with it's slotted head, was the pilot jet screw, I had adjusted all four pilot jets two turns out...

Flipping the carbs over, I removed the carb slide covers in turn and drilled out the slide holes to 2.5mm to improve the throttle response. Like the jets & emulsion tubes, the slide covers got a thorough ultrasonic clean, too. Nearly done, or so I thought.

Back to the Haynes manual and youTube for a guide to synch the butterflies. By using a shim I adjusted all four throttle butterflies to the same gap.

With the carbs back on the bike - there's some notes on throttle cable adjustment I'll add below - and it was time for a test drive.

[tanto]

It was a sleepy Saturday morning in Chiang Mai, the beginning of another hot day. Despite the forecast 32C I donned my BKS leathers & full gear - this was a test ride, after all - and headed out onto our local triple carriageway.

The road was empty. Despite some reluctance to pull away, the engine was soon up to temperature and speed. Third gear and 9,000 rpm - what speed is that? - and the sweeping bends of the road felt good. Best not to go too fast given the propensity of local scooter riders, pickup truck drivers, and livestock to emerge without warning onto the carriageway from side roads/the hard-shoulder/the fields.

The engine sounded fine. In fact, it was great! I was delighted. There was one small detail I felt sure could be fixed. On coming to a halt, the revs would drop and the engine die. Not a problem. It restarted fine. Ten miles down the road I turned round and headed home.

The following day I took the bike out again. This time it didn't run well. I posted to the forum, "Carb tuning - Classic symptoms, but what of?". I had just managed to get home after a short Sunday run, cut short by the rain. In retrospect, that was a lucky break.

In reply, Neosophist hit the screw on the head. Had I adjusted the pilot screws correctly? A few hours later I spoke to "JB", who runs a couple of RVF's in Bangkok, and he asked the same question. During our conversation it dawned on me. I checked the manual, and then the carb guide online. Duh! I had turned the pilot jets out two turns, and failed to adjust the pilot jet screws at all. Double duh!

It didn't take long to get the carbs off again, to find that of the four pilot screws, three had tightened by about one turn, while a fourth had wound out, what, eight or nine turns. It had almost fallen out into the float bowl, which would have made for an interesting engine disaster.

[krisztian_andre]

Hello,

where did you find the clutch cable, 200 seems to be very cheap?

[tanto]

Hello,

where did you find the clutch cable, 200 seems to be very cheap?

"G3", 98/2 Taiwang Road, Chiang Mai, on the RHD side, facing east, 50m from the bridge, tel 053-233600.

I'd pop round to get one for you, but I'm stuck with work and child care at the mo. No biking, or spannering, 'til the wife gets back next weekend. Grounded.

Do you come to Chiang Mai at all?

[krisztian_andre]

Was there a week ago, I'm in bangkok now. I'll call them and ask if they'll post the cables to bangkok.