Engine surge

[badboy194]

I had the same thoughts myself but as I do not know when it was last changed its got to be worth a try.

shunter v8, Did you ever get your problem solved ?

[shunter v8]

I had the same thoughts myself but as I do not know when it was last changed its got to be worth a try.

[greenbarn]

The clutch is also something I thought about right at first, because the clutch is a known problem on the 1500's.  But it doesn't really make sense it only happens in 2nd. 

[badboy194]

Your fluid should be clear.  The heat turns it from clear to yellow to brown and causes it to crystalize.  If your fluid is brown, there is probably going to be some sludge on the bottom of the reservior.  I have heard stories of many people having to replace their clutches at 5000-7000 miles.  I would suspect this was their problem.  Hopefully this is your problem because it is a very cheap fix. Either way, now you will have clean fluid so there is no loss.  Make sure you cover your bike before opening the reservior.

[shunter v8]

That is interesting and symptoms are similar,it's why only in second gear is confusing me. I have not changed clutch fluid so would do no harm to do it. Thanks

[badboy194]

It is a shot.  How old is your clutch fluid?  I had something similar to where the little hole in the bottom of the reservoir was clogging up with old fluid that had crystallized.  At certain rpm ranges it caused the clutch to disengage.  I'm not sure if that matches your description of a surge.

[shunter v8]

Thanks guys, it is a 2004 model,it has done 30k miles, it has not got the heel/toe gearchange lever it has a chrome one on it. This fault is happening well before a rev limiter would kick in. i will check ecu connections and report back, it does feel more elecrical/ fuel related but i am open to try anything.

[Bucko]

I'm not sure about other model years but my 01 definitely has a rev limiter.  I hit the limit occasionally when downshifting to pass. 

[Troll]

  I've been thinking about this, and 1, I don't believe there is a rev limiter on this engine. The redline is 5,900....but this is not about that, since it would be much easier to hit the limit in 1st...Now..some seemingly unrelated questions...How well and accurately does it shift? Is there any funny noise related to this problem? Do you still have the heel portion of your shifter installed? What I'm getting at is there has been some indication that the early models had an issue with 1-2 shift forks. I know mine had a few teeth knocked off the cluster gear, and a bent 1-2 fork when I bought it. It would hop out of 2nd and slam back in under a load....Just a thought....Like the old joke: "Doctor, it hurts when I do this"...Doctor: "Stop doing that!"

[Bucko]

I think the rev limiter kicks in at about 5k but not certain of the exact number.

The ECU is located under the seat beside the battery.  Easiest to remove the battery first to get at the ECU.

I've had an ongoing issue with the female connector pins breaking - easily spotted by looking closely at the 'mouth' of the female pins.

[shunter v8]

Thanks guys, i would say it happens at RPM rather than mph, and only in 2nd gear, i tried to get it to do it in first and third but it did not do it. where abouts is the ecu located and i will have a look at the connections. It has not reved out enough for it to be the rev limiter as it happens fairly quick after hitting 2nd gear.

[Bucko]

Sounds similar to what I feel when I hit the rev limiter - is it possible you're hitting the rev limiter only in second gear?  It wouldn't be weird that you cant go fast enough to hit the rev limit in 4th and 5th, but I would think you should be able to hit it in 3rd (and for sure in 1st & 2nd 

Or, could be your ECU is not measuring RPMs properly.  Check the ECU connector pins - That's been a trouble spot for me.

[holycow]

Look closely- does it always happen at the exact same speed (not rpm but mph)? Hmmm... or something slipping inside the throttle body...?

[greenbarn]

That is weird....   So just skip second gear... 

[Troll]

I gotta think about this...weird   

[shunter v8]

Yes only second gear. That's what I find so strange about it.

[Troll]

This is ONLY in 2nd gear? Very strange...

[shunter v8]

Okay latest update,I had two of these light up spark plug caps so I changed them for two NGK ones I had in the garage and took it a spin. Unfortunately it's exactly the same I will try and explain the symptoms better. I got the bike warmed up and did a standing start,first gear under hard acceleration no problem,second gear starts pulling then it's like hitting a very bad flat spot then getting full power back and then it does the same again almost straight away we are still in second gear,third,fourth and fifth gear all fine under hard acceleration. It has vance and Hines on it which I thought may have been the culprit,I had to get the bike government tested when I bought it and I had to put an original exhaust on it then and it was still the same.

[shunter v8]

ok thanks, i will start with plug caps then. The surge is quite dramatic like bike is being tied to a post and you are giving it throttle to try and go and then someone cuts the rope. it really is quite scary epecially 2 up.

[Troll]

Thanks all for your input. To start with the bike had new plugs filters etc about 2.5k miles ago, the bike came with plug caps that light up when the engine is running, i dont know if they are a possible cause of the fault, what suprises me it is only in 2nd gear and under hard acceleration. Greenbarn my definition of surging is it starts pulling smoothly but very quickly the power comes in with a bang and it does this twice while in second gear, i suppose to put it another way it feels like a blocked jet has just cleared its self and you are getting a rush of petrol through. Thanks for all your help.

I don't know how they are where you live, but those light up plug caps cause a world of problems here, in the States. JUNK...not meant for anything but show and trailer queens! I know what Greenbarn is getting at about a symptom description...A surge is like sitting in a rocking chair....back and forth, back and forth, or perhaps the feeling you get when riding into a headwind.

[John Hopkins]

Another thought is that you could drain a pint of gas to check there isn't water in it.

John.

[shunter v8]

Thanks all for your input. To start with the bike had new plugs filters etc about 2.5k miles ago, the bike came with plug caps that light up when the engine is running, i dont know if they are a possible cause of the fault, what suprises me it is only in 2nd gear and under hard acceleration. Greenbarn my definition of surging is it starts pulling smoothly but very quickly the power comes in with a bang and it does this twice while in second gear, i suppose to put it another way it feels like a blocked jet has just cleared its self and you are getting a rush of petrol through. Thanks for all your help.

[greenbarn]

Shunter, what exactly to you mean by "surging"- I've had different people mean different things from using that word. 

[Troll]

  I don't think it's an injector, since the fuel pressure goes up under a heavy load, due to the fuel pressure regulator. I would be more concerned about ignition issues. How old are the plugs? Is this more noticeable on a damp day? Heavy loads and worn spark plugs will make a  miss fire that can really feel interesting. Since the 1500 has dual plugs, each fired by a separate coil, one of the plugs miss firing could give you this feeling. Damp days and 15 year old plug wires don't mix well. Possible one or more wires is leaking to ground. Again, a heavy load will reveal this problem.  The fact that there is no issue when operating at reduced load indicates an ign. problem.

[John Hopkins]

It sounds like a blocked injector.

John.