Stalls during accleration

[Toeman]

I just purchased a 2008 RSV with 17K miles on it. I know I am the 4th owner and the last owner only had it for six months and drove it very little. I notice that during acceleration the bike stalls during midrange. Low and top end is pretty good but if I open the throttle all the way in 3rd or 4th it's like the key is turned off for a second. I put in new plugs today correctly gapped and put in fresh gas but see no improvement. If feels like a fuel and or carberator issue. Thinking about trying a fuel additive to see if the jets are partially obstructed. I suspect that previous owners were not good at Winterzing.

Thanks for helping.

.

Item Number: 342041

[RandyR]

A lot of RSV riders use Seafoam.

 

There are a few who use harsher chemicals, but I've found Seafaom to usually help. Start with a heavy dose. run the engine for a few minutes to get the Seafoam in the carbs, then let it sit overnight. Then take the bike out and run it. Also make sure you're keeping the revs up on the engine, the RSV doesn't lug at low rpm's like most vtwins do.

 

You might want to join the forum, the dues are minimal.

[steamer]

SEAFOAM! With that being said, since you said the bike was not used much, you should pull the carb's and give them a proper cleaning.

[bongobobny]

Yup, +1 on the Seafoam and use it regularly!

 

Now, what also was mentioned, there is a distinct difference on how to drive a V4 versus a big V Twin!! Think Ferarri, Maserati, Lotus, McLaren, GT40, etc! These bikes love their rpm's and don't like lower ones! The power band starts around 3500 rpm and keeps going up to 7000 rpm! To give you an idea of the capability, 3rd gear is good up to around 90 mph! Generally, I shift out of 1st around 20 to 25mph, out of 2nd close to 40, out of 3rd around 50 and don't even THINK of using 5th below 60! However, the way you describe your problem as falling out at mid throttle but being fine at the top of the range does suggest other issues may be causing this.

 

One of the very first things I would do, after you put a full can of Seafoam in a full tank of gas and then drive it like ya stole it until the tank is empty, is to either learn how to properly sync your carburetors or find someone who will sync them for you. If your carbs are way off this can affect performance! You can also check your float level adjustment which will also cause issues.

 

Another possibility, but not that likely is a bad Throttle Position Sensor. There is a connector you can disconnect and monitor its performance with an ohmmeter but this is not a normal failure. The TPS seems to be pretty reliable.

 

The third thing is to make sure your engine is firing on all 4 cylinders. It is a known fact that these bikes run surprisingly well on 3 cylinders! You also may have an issue with your plug caps, inside the cap under a little set screw is a spring, a disc, and a resistor element that can develop tarnish or corrosion which will cause a weak spark. One thing to try is to buy yourself a cheap spark gap tester from any auto parts store and test each cylinder. You should be able to pull a spark gap of at least 0.100 inches, I believe the spec is actually 0.109 inches. A quick test to see if you are just plain firing on all 4 is to start a cold bike and carefully feel all 4 exhaust pipes immediately to see if they are heating up uniformly. A quick touch with a finger will suffice...

 

If all else fails then you may be in for a complete carb disassembly and cleaning from the bike setting too long with that nasty corn squeezing gas! Hopefully, some Seafoam will fix things.

[Toeman]

A lot of RSV riders use Seafoam.

 

There are a few who use harsher chemicals, but I've found Seafaom to usually help. Start with a heavy dose. run the engine for a few minutes to get the Seafoam in the carbs, then let it sit overnight. Then take the bike out and run it. Also make sure you're keeping the revs up on the engine, the RSV doesn't lug at low rpm's like most vtwins do.

 

You might want to join the forum, the dues are minimal.

thanks for the help, I just joined.

[cowpuc]

I have been riding 1st Gens for a good while now and have never owned a 2nd Gen so take this for what it is worth (probably not much). My 1st Gens, when tuned and running properly would/will pull rock solid in 5th gear from 30 mph to 130 mph - no stumbling. Matter of fact, one of the ways I like to test their tune and other important parts/pieces (like stator, regulator, diaphram conditions) is to do exactly that - run it down to 30 in 5th -open it up and see what happens (an example of this can be seen in the video below, you will need to start at .20 on the time line there though as traffic was not to conducive to my "tests" - this was a pull done completely in 5th gear - loaded up for traveling and 2 up riding).. One of things I have also admired most about the 74 inch V-4 is actually its ability to crawl at low R's thru the mountains and still maintain an amazing amount of spunk in high R's..

All that said,, and in total agreement with what had already been posted for things to look at, if it were my scoot I think I would also take a close look at the carb diaphrams and ease of slide movement. What I am reading here makes me think of what I always referred to as a mid range "flat spot".. Generally speaking, that type of flat spot (or bog) on an out of tune scoot is usually mitigated thru metering rod adjustment to fatten up the mid range mixture.. Considering that the metering rod on our V-4s is under vacuum control and knowing how many times I have patched up diaphrams on my 1st Gens,,,,,,,,, well,,, thats why I would head there if it were mine....

 

Edited July 5, 2018 by cowpuc

[Toeman]

I have been riding 1st Gens for a good while now and have never owned a 2nd Gen so take this for what it is worth (probably not much). My 1st Gens, when tuned and running properly would/will pull rock solid in 5th gear from 30 mph to 130 mph - no stumbling. Matter of fact, one of the ways I like to test their tune and other important parts/pieces (like stator, regulator, diaphram conditions) is to do exactly that - run it down to 30 in 5th -open it up and see what happens (an example of this can be seen in the video below, you will need to start at .20 on the time line there though as traffic was not to conducive to my "tests" - this was a pull done completely in 5th gear - loaded up for traveling and 2 up riding).. One of things I have also admired most about the 74 inch V-4 is actually its ability to crawl at low R's thru the mountains and still maintain an amazing amount of spunk in high R's..

All that said,, and in total agreement with what had already been posted for things to look at, if it were my scoot I think I would also take a close look at the carb diaphrams and ease of slide movement. What I am reading here makes me think of what I always referred to as a mid range "flat spot".. Generally speaking, that type of flat spot (or bog) on an out of tune scoot is usually mitigated thru metering rod adjustment to fatten up the mid range mixture.. Considering that the metering rod on our V-4s is under vacuum control and knowing how many times I have patched up diaphrams on my 1st Gens,,,,,,,,, well,,, thats why I would head there if it were mine....

 

 

Thank you very much

[Toeman]

Yup, +1 on the Seafoam and use it regularly!

 

Now, what also was mentioned, there is a distinct difference on how to drive a V4 versus a big V Twin!! Think Ferarri, Maserati, Lotus, McLaren, GT40, etc! These bikes love their rpm's and don't like lower ones! The power band starts around 3500 rpm and keeps going up to 7000 rpm! To give you an idea of the capability, 3rd gear is good up to around 90 mph! Generally, I shift out of 1st around 20 to 25mph, out of 2nd close to 40, out of 3rd around 50 and don't even THINK of using 5th below 60! However, the way you describe your problem as falling out at mid throttle but being fine at the top of the range does suggest other issues may be causing this.

 

One of the very first things I would do, after you put a full can of Seafoam in a full tank of gas and then drive it like ya stole it until the tank is empty, is to either learn how to properly sync your carburetors or find someone who will sync them for you. If your carbs are way off this can affect performance! You can also check your float level adjustment which will also cause issues.

 

Another possibility, but not that likely is a bad Throttle Position Sensor. There is a connector you can disconnect and monitor its performance with an ohmmeter but this is not a normal failure. The TPS seems to be pretty reliable.

 

The third thing is to make sure your engine is firing on all 4 cylinders. It is a known fact that these bikes run surprisingly well on 3 cylinders! You also may have an issue with your plug caps, inside the cap under a little set screw is a spring, a disc, and a resistor element that can develop tarnish or corrosion which will cause a weak spark. One thing to try is to buy yourself a cheap spark gap tester from any auto parts store and test each cylinder. You should be able to pull a spark gap of at least 0.100 inches, I believe the spec is actually 0.109 inches. A quick test to see if you are just plain firing on all 4 is to start a cold bike and carefully feel all 4 exhaust pipes immediately to see if they are heating up uniformly. A quick touch with a finger will suffice...

 

If all else fails then you may be in for a complete carb disassembly and cleaning from the bike setting too long with that nasty corn squeezing gas! Hopefully, some Seafoam will fix things.

 

 

great things to check on

[M61A1MECH]

Another thing to check on second gen Ventures is the air intake system.

On my 07 I would get a flat spot when accelerating after I installed K&N filters, felt like the bike was going to stall completely out, I had to adjust the needle shims out by one shim.

I also made the mistake of opening up the air boxes to increase the air flow, again flat spot on hard acceleration, not as bad but bad enough that I replaced the modified air boxes with stock air boxes.

 

So just something else to check.

[cowpuc]

Another thing to check on second gen Ventures is the air intake system.

On my 07 I would get a flat spot when accelerating after I installed K&N filters, felt like the bike was going to stall completely out, I had to adjust the needle shims out by one shim.

I also made the mistake of opening up the air boxes to increase the air flow, again flat spot on hard acceleration, not as bad but bad enough that I replaced the modified air boxes with stock air boxes.

 

So just something else to check.

 

and just for clarity sake,, the "needle" M6 is mentioning here is the same thing that I am referring to as a "Metering Rod" = same thing just using a different name). Most bikes use a "E" clip on the Needle/Metering Rod that hangs down from the carb slide for adustment sake. Our Ventures (except for the Canadian models I am told? @Marcarl , do the Canuckian Ventures have clips on those Needles/Metering Rods?), for some reason have no factory way of adjusting them so "shimming" with nylon washers is a fairly easy way around that malody.. If you do decide to attempt shimming,, its not a bad idea IMHO to steer clear from using metal washers as they add weight to the slide and can interfer with slide movement... Just a heads up..

Again,, this is all being mentioned by someone who has NO experience with the 2nd Gen so a true guru may come on here and blow this all out of the water,,, so to speak..

[Toeman]

I have been riding 1st Gens for a good while now and have never owned a 2nd Gen so take this for what it is worth (probably not much). My 1st Gens, when tuned and running properly would/will pull rock solid in 5th gear from 30 mph to 130 mph - no stumbling. Matter of fact, one of the ways I like to test their tune and other important parts/pieces (like stator, regulator, diaphram conditions) is to do exactly that - run it down to 30 in 5th -open it up and see what happens (an example of this can be seen in the video below, you will need to start at .20 on the time line there though as traffic was not to conducive to my "tests" - this was a pull done completely in 5th gear - loaded up for traveling and 2 up riding).. One of things I have also admired most about the 74 inch V-4 is actually its ability to crawl at low R's thru the mountains and still maintain an amazing amount of spunk in high R's..

All that said,, and in total agreement with what had already been posted for things to look at, if it were my scoot I think I would also take a close look at the carb diaphrams and ease of slide movement. What I am reading here makes me think of what I always referred to as a mid range "flat spot".. Generally speaking, that type of flat spot (or bog) on an out of tune scoot is usually mitigated thru metering rod adjustment to fatten up the mid range mixture.. Considering that the metering rod on our V-4s is under vacuum control and knowing how many times I have patched up diaphrams on my 1st Gens,,,,,,,,, well,,, thats why I would head there if it were mine....

 

 

Thank you for the assistance.

[cowpuc]

Thank you for the assistance.

 

You betcha Toe,,, any time!

[Patch]

Puc why is that bike running so hot?

 

I know I shouldn't ask in this thread

 

Patch

[cowpuc]

Puc why is that bike running so hot?

 

I know I shouldn't ask in this thread

 

Patch

 

Very fair question Patch,, good eye!! You might be getting snickered by camera angle or something of the sort Patch but I will say this - all of my 1st Gen MK1's ran high on the meter,, 1 or 2 needle widths away from the red zone and this one does exactly as the others.. I ran em hard thru all kinds of ambients including +120 degrees out in Death Valley and they just like to hang out at that 1 or 2 needle widths away from the red.. Matter of fact, the bike that your looking at saw 119 last year on a quick trip to the west coast and same old same old..

Another short note to the readers here before I surrender for another 3 months probation for ing Toeman's thread,,, if you happen to land one of these early 1st Gens, BEWARNED and dont be fooled by what I am talking about here.. True, this early models, at least all of mine, do run high on the gauge BUT they also came with a plastic impellar in the water pump that = left to its own demise = Murphy can (and probably has) destroyed 1st Gen engines because the owners didnt get the water pump updated with the aluminum impellar... If your 1st Gen is prone to actual over heating or it regularly plays in the red zone = check the water pump!!!

OK,, now wheres that penalty box (Sorry @Toeman )

[bongobobny]

Yup!! A known fact is the temp gauge on MK1's all read high. The bike itself is not really running that hot. They fixed the issue along with several others with the MK2...