Pls point me in the right direction (starting issue)

[EricV]

Hi all. So as updated some time back I have my engine re-installed in my 630. It runs/sounds great. Cleaned TB while that was off, went over connecters six ways to Sunday when re-installing engine, flushed cooling, bled brakes, etc. Heres the thing, though...just not sure where to start.

It's always required the cold start lever- a few of ours have had the need and others not. Go figure. Mine would always fire right up and idle high, as it should w/ the enricher lever pulled, and then of course release the lever and it settles into it's usual idle. Now, since the first start after getting it all buttoned back up (and each after, consistently, on cold starts only), it does start (1st shot) but it takes slightly longer (a few secs) for the engine to fully start and then, once running, the idle is low (again this is w/ lever pulled, and it's at around 1700 like w/out the lever.) So after just a few seconds the idle does shoot up to the usual lever pulled high idle. Quick warm up, release, idles at 1700. Runs nice. Each warm start after is normal. When warm it fires up normal/fast, as it should.

So I'm just not sure where to start. I cleaned the TB, and of course a lot of wires/connectors were worked during the engine removal/reinstall, but I was very careful w/ all and all went smoothly. And it runs great. There's something about this very earliest phase of starting, when stone cold and just a few secs, when it idles low..then all goes normal. Any input is appreciated.

 

[Theo]

A pair of years ago, after having disassembled and then reassembled the engine (and having cleaned the TB), my 610 started like in this video:

After those first seconds, it ran fine. I used it some times and then the problem vanished and now it starts as usual.

 

[EricV]

Thanks Theo. Yes, that's pretty similar, but the thing with mine is that it does it every cold start, always exactly as described in previous post.

 

[SilverBullet]

Have you actually been out on a good long ride yet or just starting and running the bike at home? I was thinking maybe its been too cold outside for you to ride and the ECU after being disconnected and without power has to relearn some settings I believe.

_

 

[EricV]

Have you actually been out on a good long ride yet or just starting and running the bike at home? I was thinking maybe its been too cold outside for you to ride and the ECU after being disconnected and without power has to relearn some settings I believe.

_

Good point. I'm embarrassed to say she still resides in the kitchen. It's been cold as he*l here and there have been other projects I'm dealing with (both bike and non-bike...on the bike new rubber, some coolant leaks, etc.) This weekend I'll be getting it out of the house and will take it on a shake-down ride, weather permitting (supp. to be warm, but poss. rain.) Perhaps a good ride and some "cycling" of the systems will work this out. Thanks for the replies.

 

[EricV]

Ok- took it out on it's shake down ride after work today. Long time coming...had been hoping to get out this past weekend but Murphy (He of said Law, who rules my life with an iron fist) saw to it that I'd spring a coolant leak in a place that required dismantling much of the system to get to.

Anyway, the issue remains the same on cold start (precisely as described in first post of this thread) and, again, I'm just not sure where to start on it. Good iridium plug, cleaned TB, all connectors good as far as I can tell, and the thing starts fine warm and runs great. Also, fully warm and underway, I'm not getting exhaust popping (well, there's a very, very slight popping and not all the time...negligible to the point of an observer saying "nah, that's not popping.")

Now the thing that's niggling in my mind is that one header pipe. No matter how I'd situate it, it would never seat in the mating depression absolutely perfectly (like a hair- and I mean just a hair- of a gap on one side of that one head pipe...no matter how many ways I'd gently turn it trying to get a perfect mate.) I discovered it was this way from the factory when I'd disassembled it to remove the engine. I mention this as, if anything, it's mated better now (close to perfect) and I didn't have this starting issue before. I'm hoping it's something else because, for whatever reason, getting that exhaust right was probably The Most difficult part of this journey. As you know the headers have to be perfectly aligned to receive the mid-pipe, which has to be in precise position in order for the mid and rear mounts to align with their mounting points (mine's the FMF mid-pipe and can.) Anyway getting all of that on correctly/aligned was a bear as the slip joints (headers to mid) aren't smooth.

I'm also not sure if I have the throttle cables perfectly adjusted. I tried to keep the nuts/adj. barrels just as they were, but those moved a bit on re-install. I adjusted it as the manual describes (so that it has a couple mm of play at the grip, closed) and it feels right (can hear butterfly slamming to it's "at ease" position upon release...just feels right.) Now during it's initial runs (upon completion of engine re-install, to warm up and make sure all ran right) my idle was slightly higher than normal so I did adjust that back to 1650.

As usual sorry to go long...just wanted to offer up all info to aid you in aiding me. I am happy that the bike runs great- it's been five months and much money since that brick dropped in my pants, and it's good to be getting back on...right in time for our season. I'm going to ride it to work tomorrow and tool around during lunch to continue to study it and see if the ECU is still re-learning (though I seriously doubt that's possible, at this point.)

Thanks gang, for any advice and for bearing with me during this journey.

 

[SilverBullet]

I would just keep riding it for a bit longer before I started tinkering. The throttle body to throttle grip adjustment can be easily checked with iBeat.

 

[EricV]

Thanks man. I did re-set the TPS as the last step before that 1st start up. I'll tool around today to see what happens (and to build confidence in the bike before going on a long ride this coming weekend.)

 

[DYNOBOB]

Was the bike warmed up before the TPS reset?

.

 

[EricV]

Was the bike warmed up before the TPS reset?

.

According to what I'd read the last thing to do (prior to starting up an engine that's been out) is to set the TPS...so I did, of course. Now if memory serves I did do it again after it was warmed up, but it would be smart to check that- I will. Still, given that it does start up cold (just hesitantly so) and it starts fast when warm, I'd like assume the TPS is set correctly (reinforced by the fact that iBeat says it's done successfully.)

 

[Theo]

can hear butterfly slamming to it's "at ease" position upon release...just feels right.

I don't take it for granted that the throttle is perfectly fine if you hear that noise.
This is what happens when you adjust the cables:

(luckily) what you hear is not the butterfly being slammed: it's that kind of wheel hitting the stroke-end screw.
But what happens if I set it barely tight enough in order to hear the contact noise?

I can slide the piece of newspaper between the surfaces, therefore it makes a noise because the run-up given by the closing action warps the cable/wheel for a moment, but a moment later there is no contact.
Anyway, I doubt that this is your problem, first of all because I doubt that the little clearance makes the butterfly opened enough to be noticed and secondly because you wrote:

I adjusted it as the manual describes (so that it has a couple mm of play at the grip, closed)

.
I just wanted to share my experience.

 

[EricV]

Thanks Theo. Yes, I have understood what's slamming home on the throttle (the circular thingie to the stop, as opposed to the actual butterfly)- I could have phrased that better...but thanks for posting the vids. I also don't think that's the issue, reinforced by the fact that it starts so well/normal when warm. It's gotta be something about the cold start circuit/routine- again it's a little hesitant to start and then, once started (and with the cold lever pulled in), it idles low for a bit (say 7-15 seconds) and then ramps up to high idle. It's running fine otherwise, so I'll be taking it out on a longer ride this coming Saturday and then, after that (maybe Sun.) I'll pull the airbox and re-inspect the adjustment, hook it up to iBeat and also check whatever else I can. I'll also drain the oil and check the screens as the thing just had the rebuild (just to make sure there's no re-assembly debris in there and make sure all looks healthy.)