Is Low RPM Hesitation Normal?

Hey everyone. Well I've had my 2000 VFR for a month now and although the weather hasn't cooperated fully, I have been able to get out for several days of riding (yesterday in torrential rain, but still fun). It usually takes me a bit of time to get used to a new bike, sometimes longer than others, this one on the short end. I'm LOVING THIS BIKE!!!!! It is very quick but very predictable, very stable, very nimble, all around easy and fun to ride. I've gotten a lot more comfortable a lot quicker than on any other bike I've had. It's a beautiful thing.

One question, I've noticed that just as I'm taking off in 1st but then again in 2nd or 3rd if I let the rpm go low, the motor sounds like it might be a bit rough - sort of a gurgling sound (very scientific - sorry). This happens b/w about 1500 to 2500 rpm. Once I have it up above 3000 or so, she sings beautifully. I haven't decided whether there is actually a hesitation or flat spot, or if there is just a sound difference. It's not a big deal from a riding standpoint - I usually have it above 5k anyway, but just thought I'd ask.

Thanks,

Jm

 

take it easy on first to second gear shifts, I short shift the bike but am not afraid to rev it, dont lug the bike (too high a gear for the RPM)

 

What you describe is fairly common, being an early Fuel Injected bike. If you decide it is too much and you want to try to improve it some things you can try are:
* balance/synchronise the starter valaves
* power commander / dyno tune map
* throttlemeister

 

Yeah these bikes aren't really happy below 3k. I did a pair valve blockoff and it improved the low rpm performance noticeably, but I still have to try and avoid that range.

 

Thanks for these responses. The engine isn't being lugged, I'm talking about moving through the gears from a start, which I might not have made clear. The revs quickly climb through 3500 where it smooths out considerably and with very strong power. Just to determine that it wasn't just in first gear, I dropped the revs in second and third down low and listened to the engine, and again it just gets rough sounding - even with no strain on the engine. So I think it's right that it's just not happy below 3k.

Psyberg, how would a throttlemeister help? Isn't that a sort of cruise control thing?

 

My mistake, I meant to say Throttle Tamer. I haven't got one myself, but have read that others ahve found them useful in curing snatchy throttle response at low revs/throttle positions.
G2 Tamer Throttle Tube

as others have said, it can be avoided by ensuring the revs stay high, however, I realise this is not always a practical solution, especially in start/stop traffic etc.

 

^^^^^

Yessir, pair mods is first then PC.

Many "hesitation" problems can be fixed by using more throttle and slipping the clutch through the narrow rpm range where you might notice it.

 

Throttle Tamer...interesting gadget, thanks. For now I'll focus on a more deft hand at the throttle and higher revs. HST, keeping the revs higher will solve the issue I'm experiencing, but it doesn't change the fact that the motor doesn't like low RPMs.

Can someone point me to any how to thread on pair valve blockoff as stated above? I have no idea what that means. The Power Commander I'm familiar with.

Thanks everyone! Very helpful input and responses.

 

Yes sir! A v4 like this is not happy below 3,000 rpms or so. It will be much happier if you keep it between 4-6k rpms.

enjoy the ride! you will still get great gas mileage

 

As you seem to be talking about a transient roughness from just above idle possibly your SVs need balancing, mine are balanced ever major service and luckly the mechanic ( Ex Honda ) allows me to hover around him when doing them....Usually only one is a little off but notice the extra throttle crispness off the line when leaving....

 

Tink, a Harley?? Puhlease!!

I'll just be happy to rev up the machine like it likes. Seriously, I do ride it above 3k - more like 5k most of the time. It's just off the line that I noticed this. Maybe I should rev it up to 3k there and slip the clutch a bit more as has been suggested. i doubt I'll screw around with the PAIR thing for now, this is not a major deal for me at this point.

 

You might be right, but frankly it is hard (for me) to tell even from the riders seat. Let me spend some more days riding and really try to pay attention to what's going on. This bike is still new to me after all. I'll report back in the future. Thanks again to everyone for their thoughts.

 

Remember, a throttle has only 2 positions: All the way closed, or all the way open!

 

Ha Ha - Agree! Especially here in Illinois where there are 11 curves in 318 miles! Hmmm...maybe I should do a search for good radar detectors

 

When a Pair valve stuck open a few years ago it caused back firing especially on underrun and the fuel economy went bad I degummed it which fixed it but ended up blocking it anyway as it was an easy thing to do and don't have to worry about it again.....

Re the low speed running rough thing, clearly not your problem but there are quite a few threads here where new riders to the VFR coming from Cruisers complain about problems riding in low revs ie 2.5K in higher gears only to learn very quickly with its 11K Redline the VFRs V4 likes to be above 4K.

One other thing to check is has someone de-snorkeled yours, while I loved it's extra induction noise after trying it out for 1200 miles in various conditions put it back in due to it making my low>mid revs feel fluffy though as your issue is "Off idle" I'd still look to having your SVs balanced if you don't know when it was last done, if done correctly can only improve things.

 

The engine is a V4 but it's not like cruiser v-twin. These engines need mid to high rpms just like an inline 4 engine. Stay at 4k or above and your engine will be happy.