Cold starting - choke kills it

[h0gWash]

So I have a slight issue with my 1988 FJ1200 3CV which has 36K miles on the clock. I've had it about 2 weeks and covered ~400 miles already. I have not had to top the oil up. The only issue I have found - difficult to start when engine cold. Choke on it's impossible to start and once started (still cold) using the slightest amount of choke stalls the engine. I should say I've searched for quite some time on this forum and the net more generally but haven't found what I'm looking for.

Here's a brief run down of symptoms: First thing in the morning I roll it out the garage, put it on the center stand and press the starter. After a few turns the engine fires. If I'm lucky the engine will stay running at very low RPM maybe 200-300. If I crack the throttle a little the bike does respond with a little smoke and noise which sounds like a chain. Sometimes the only way to keep it running is to roll the throttle ever-so-slightly and hold to keep from stalling. Sometimes I'll need the throttle open just a little for the engine to fire in the first place. If she's feeling kind there's no need for throttle at all and she'll stay running until the engine is warm, RPM raises to just under 1000, no smoke in exhaust.

Before getting to this point (warm engine, 1000RPM) the engine [normally] keeps ticking over just/barely. You would have thought that a little choke would go down well whilst this is happening but just the slightest pull stalls the engine immediately. Perhaps there's a slight uptick in RPM before it does.

It's worth stating that once ridden around and up to full operating temperature there are no starting issues whatsoever. No choke and engine fires after 2-3 turns with no issues, no smoke whatsoever, no unpleasant noises.

This is a winter project and I've given myself a challenge so I can learn a good amount about bike mechanics and come out with a sweet bike at the end of it.

My plan (for the bike generally, tools are on their way)
Check valve clearances
Check cylinder compression
Clean and refurbish carbs
Rebuild breaks (already have blue dots on front). They stop me but front lever travel is only a few mm. Then I have to squeeze it quite hard
Replace rear shock

So all that said I'm looking for a prognosis and some ideas on what my symptoms could be caused by. Have I got the next steps right?

Thank you!

[Pat Conlon]

Good list of things to do.... All new owners should do this 

Re: Carb Cleaning: You may want to check this first before the complete overhaul of the carbs: In the carb bowls, at the bottom, there is a small hole which is the pick up point for fuel used in the choke circuit. If this hole or passage is blocked by debris, your engine will starve for fuel when the choke is applied.

Re: Front Brakes: Consider a 14mm master cylinder (m/c) for your front R-1 brakes. (eBay) The FJ's oem 5/8" (16mm) m/c is fine for the oem FJ calipers but when upgrading to the YZF R-1 calipers, the smaller diameter piston in the 14mm m/c just flat out works better.

Cheers

Pat

[h0gWash]

Nice one thanks Pat, that's me now for the next hour having a look on ebay and seeing what I can find on servicing the choke circuit

[copper]

You probably should check with Robert or Randy at RPM. They have everything you need for your carbies

[Pat Conlon]

Glad to help.

Don't shop FleaBay for your carbs....Go to RPM. Spend $22 and get this: http://www.rpmracingca.com/proddetail.asp?prod=carbkit&cat=24





While you're in the carbs, throw away all those soft JIS screws and install the stainless Allens, also replace the float needle seat O rings. A very common leak point problem with the CV Mikuni's.

[h0gWash]

Appreciate the tips for sourcing those parts and the heads up to replace whilst I'm in there. I'm going to try the suggestion of clearing the pick up point hole in the choke circuit before going mad. Actually to be honest I'm likely to over hall eventually, testing the bike on nice straights it gets a little breathless at higher RPM.

Do I have to be picky on the year for the 14mm YZF R-1 master cylinder? Cursory look shows FZ-1 suitable too. Are there more I can be looking out for, any need to be cautious of year with those?

[Pat Conlon]

The FZ-1 m/c is what I use. I like the adjustable lever too...

[Fj.itis]

x2 on the carb bowl choke circuit blocked, that jet in there is so tiny.