Fair enough. Timing/valve lash differences can change the sound as well. I suspect that is where his issues lie.
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Cold Weather Running Question (and history)
- Thread starter WestBrantKid
- Start date
Great information, thanks!
My mixture screws are sealed, so they'll be factory set for non-ethenal fuel, as you say. I never thought of that, and should fix that. I don't think that's the reason for my current issue though because the carbs, as they are, were on the bike that run great all last winter. But those same carbs on a different, but identical engine, did not solve my issue on this different engine. So it must be something other than the carbs.
I used to do a lot of engine swaps and other things back in my teens and early 20s, but haven't done any of that (other than brakes and oil changes) in about 25 years. Now I seem to have lost a lot of that knowledge, and I've never done my own maintenance on my bikes until about a year ago. Very frustrating.
So, I'm trying to remember where vacuum comes from. Where does it start, and does it run through the carb, or does it come from the carbs?
About the jets, I'm told by the previous owner of this bike that the jets were replaced with the GSXR jets. The GSXR was fuel injected by this time, so I can't say if he was feeding my a lie, or if the last carbureted GSXR had compatible jets, or maybe it was an aftermarket equivalent. Is there a way to measure the jets?
The bike, on cold days of around 10°C and below, has trouble starting. Let's say 5 or 6 attempts, rather than 1st attempts on warm days. But once started, and ran with full choke, gradually lowered to off over a period of about 2 minutes (compared to 10-20 seconds on warm days), it will idle good, but hesitate when given throttle slowly, and stall if given throttle normally. I have to easy the throttle and hold it at 3-4000 RMP for 10-20 seconds, and do this several times, before I can drive away slowly. Once on the road I have to accelerate slowly to avoid hesitation, and can't go over about 4-4500 RMP. If I'm at about 4-4500 RMP more throttle only causes it to slow down. But this only lasts for about 500m. Usually by the time I get to the end of my street and turn onto the main road it's cleared up and running good.
Ok. Vacuum is generated in the carbs by them restricting the air flow (piston moves down but can't fill the cylinder with ambient pressure air as airflow is restricted by carb). Anywhere between the throttle (slide/butterfly/choke plate) and the intake valve could have a leak that allows air in without the required extra fuel being added. In practice, leaks are normally around the rubber boots or an open vacuum port or cracked vacuum hose.
If GSXR was fuel injected, GSXR jets make no sense. Even if it referred to a carb version of GSXR, again, may not matter. You need the right jets for your motor (which is often richer than factory as they were handcuffed by emissions). You might be able to measure a jet with gauge wires. Hopefully they are stamped to make your life easier (and haven't been drilled). Which jet you have now isn't that important. You need to diagnose your issue first. If your issue is running lean, then you need to know the current jet to make an educated guess on replacement jet size. I wouldn't be randomly throwing jets at it until I had solid evidence that my mixture was wrong (and other issues like valve adjustment had been checked).
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No, I started to swap the exhaust, but it wasn't plug and play. I would have to have trimmed the pipe and decided not to.
You think the exhaust could cause this issue?
If the exhaust on the happy bike is partially plugged, that would richen the mixture and change how the bike runs. Possible but not likely imo.
My 03 has Hindle exhaust. The 01 had a chrome exhaust of an unknown aftermarket make. The decal peeled off.
Is this thing just "cold bloded" and needs a good warm up? I don't think it would be the first.
Ah ok, so they are different. May make a difference. I'd be surprised if two aftermarket exhausts made that much difference off idle when cold. The bigger difference should come at high throttle and high rpm.
I think we can rule that out since one bike runs great in the winter and the other doesn't. If that was the case, neither would run great.
I have no time at the moment, but I hope to have time to work on the 01 soon because the carbs off the 03 are ready to be put on, and the bike re-assembled. I'm curious how it'll run in the cold with the carb swap. That'll be the only change from last winter to this winter.
Btw, 16°C when I left home this morning and no problems.
Because of an elbow tendon issue I haven't ridden in a couple weeks (when it was warm). I started the bike on the weekend when it was cool, (was it around 8°C? I can't remember), and it was hard to start as I've described. That's what prompted this post. But it was nice this morning, and I missed riding, and the elbow is a little better, so I decided to ride to work. Glad I did!
Btw, 16°C when I left home this morning and no problems.
Because of an elbow tendon issue I haven't ridden in a couple weeks (when it was warm). I started the bike on the weekend when it was cool, (was it around 8°C? I can't remember), and it was hard to start as I've described. That's what prompted this post. But it was nice this morning, and I missed riding, and the elbow is a little better, so I decided to ride to work. Glad I did!
Loud iirc. Used to be popular. That one looks long enough that it may be a reasonable volume.
Personally, I like the sound better than the Hindle, but it doesn't seem to be any louder. I've never liked loud.
TK4
Well-known member
D&D exhausts were made in Texas - long since defunct. Good stuff back in the day, but loud.
I bought the 03 in 2008, and it had the Hindle on it when I bought it.
Look at the collectors. Easy to see 4-1 vs 4-2-1.
EDIT:
Random pics for examples, yours may look different.
Collectors?
Okay, my headers go 4-1, then into the baffle (muffler?)
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