RPMS on venture

[Edbo]

Ok I have a question. what instrument do you use to check the RPMS on your bike if it doesn't have a Tachometer?

[pbjman]

Hi there. It depends on what you are checking for. Shift points? Idle speed? Most people ride and tune by ear. Many have installed aftermarket tachs. There is a rev limiter her so you don't have to worry about overdoing it.

If you can be specific about what you are looking for, there are people here who will be able to answer it.

[Chaharly]

Alot of guys install a tach. There is a write up on the Read Only section of the 2nd gen tech talk. If you're trying to sync the carbs or set the idle I know that most shops have a little tool you just set on the motor and it can somehow figure out your R.P.M.s

[Edbo]

What I'm looking at is when you are checking the charging system they say to run the RPMS up to 5000 without a tach I don't know what I'm turning, just wondered if there was a way to check, also to set idle RPMS. I know I can install a tach but not wanting to spend that much right now. If some one knows of a cheaper tach I would be interested.

[naturbar]

"they say to run the RPMS up to 5000"....... IMO "they" are off the mark with that suggestion. I may be wrong but logic dictates that if one needed to run engine to 5000 rpms to get the maximum voltage output.....then we would need drive around at that same rpm to keep battery charged? Hand held tachs are available which facilitates what you are requesting....good luck.

[bongobobny]

Yah! The main idea is to see if voltage increases with engine speed. You don't need a specific RPM, just increase the RPM's to see if the output of the R/R increases, or if you are looking at AC voltage out of the stator, each winding should increase and be approximately the same voltage as the other two windings...

[friesman]

What I'm looking at is when you are checking the charging system they say to run the RPMS up to 5000 without a tach I don't know what I'm turning, just wondered if there was a way to check, also to set idle RPMS. I know I can install a tach but not wanting to spend that much right now. If some one knows of a cheaper tach I would be interested.

 

Here is the tach I bought, it was a great price (12 bucks) and arrived in about 3 weeks with no taxes or shipping costs. I havnt installed it as my bike is in storage, but it looks pretty good quality esp considering the price http://www.aliexpress.com/snapshot/6339416501.html

[Edbo]

That's what I'm looking for thank you. Thanks for everyone's replies.

 

 

Eat to ride, Ride to eat

[V7Goose]

Here is the tach I bought, it was a great price (12 bucks) and arrived in about 3 weeks with no taxes or shipping costs. I havnt installed it as my bike is in storage, but it looks pretty good quality esp considering the price http://www.aliexpress.com/snapshot/6339416501.html

 

DO NOT BUY the referenced tach from the post above unless you fully understand what you are doing!

That tach probably will not work for you unless you are willing to build a pulse adapter. From the specs, it looks like it is designed for a typical engine with a single coil and a distributor - the lowest setting is 4 cylinder, which will expect two pulses per revolution. Although our engines are 4 cyl, they have no distributor - each cylinder has its own coil, which would lead you to believe that it needs a tach designed for a single cylinder engine, but that is not right either. The ignitor on our engine fires each coil ONCE per revolution (the second pulse is a waste spark during the exhaust stroke), so a tach that works on this engine must be designed for use on a typical 2-cylinder engine.

 

The real key is knowing how many PPR (pulses per revolution) the tach needs. Four-stroke engines that use a single coil typically produce a number of PPR = 1/2 the number of cylinders, thus a 4 cylinder engine will provide 2 firing pulses during each engine revolution. In contrast, a two-stroke engine will produce one firing pulse for each cylinder during every revolution (twice as many as needed on a four-stroke engine). Tachometers designed for cars usually only specify the number of cylinders, which often confuses the non-technical buyer. Tachometers designed for motorcycles or boats are more likely to specify the required PPR.

 

As I stated above, each coil on the RSV will produce 1 firing pulse during each engine revolution.

Goose

[MikeWa]

This tach only requires one wire which coils three wraps around any plug wire. It's not very fast but it does the job for me.

 

Mike

 

[friesman]

DO NOT BUY the referenced tach from the post above unless you fully understand what you are doing!

That tach probably will not work for you unless you are willing to build a pulse adapter. From the specs, it looks like it is designed for a typical engine with a single coil and a distributor - the lowest setting is 4 cylinder, which will expect two pulses per revolution. Although our engines are 4 cyl, they have no distributor - each cylinder has its own coil, which would lead you to believe that it needs a tach designed for a single cylinder engine, but that is not right either. The ignitor on our engine fires each coil ONCE per revolution (the second pulse is a waste spark during the exhaust stroke), so a tach that works on this engine must be designed for use on a typical 2-cylinder engine.

 

The real key is knowing how many PPR (pulses per revolution) the tach needs. Four-stroke engines that use a single coil typically produce a number of PPR = 1/2 the number of cylinders, thus a 4 cylinder engine will provide 2 firing pulses during each engine revolution. In contrast, a two-stroke engine will produce one firing pulse for each cylinder during every revolution (twice as many as needed on a four-stroke engine). Tachometers designed for cars usually only specify the number of cylinders, which often confuses the non-technical buyer. Tachometers designed for motorcycles or boats are more likely to specify the required PPR.

 

As I stated above, each coil on the RSV will produce 1 firing pulse during each engine revolution.

Goose

 

 

THanks for the input, Goose. I thought moving the switch from 4 -8 would compensate for the wasted spark,i was converting the wrong way, .

Edited December 9, 2014 by friesman

[Edbo]

This tach only requires one wire which coils three wraps around any plug wire. It's not very fast but it does the job for me.

 

Mike

 

[ATTACH=CONFIG]95708[/ATTACH]

Ok I have bought similar to one like this and it has a adjustment as far as how many pulses per revolution. I have it set so that at idle I'm turning 1000 RPMS but when I'm running at speed of 50 mph it says I'm turning 1500 rpm, according to the charts I looked at on the other sight they show that I should be turning close to 3000 rpm , so wanting to find some kind of tach that I can check the accuracy of this unit. How many RPMS does your unit show your turning at 50 mph?

[MikeWa]

Ok I have bought similar to one like this and it has a adjustment as far as how many pulses per revolution. I have it set so that at idle I'm turning 1000 RPMS but when I'm running at speed of 50 mph it says I'm turning 1500 rpm, according to the charts I looked at on the other sight they show that I should be turning close to 3000 rpm , so wanting to find some kind of tach that I can check the accuracy of this unit. How many RPMS does your unit show your turning at 50 mph?

 

I don't know what you have. None of the ones I looked at had any adjustment. There are two basic units available. One for single spark and one for waste spark. Some will also show hours of operation. Mine flashes the hours every one hundred hours. Perhaps your adjustment should be set to one pulse per revolution since we get a waste spark on the exhaust stroke. I think I paid 25 dollars for mine some years ago from Yamaha Sports Plaza. It was found in the generator section.

 

Mike

[Edbo]

I don't know what you have. None of the ones I looked at had any adjustment. There are two basic units available. One for single spark and one for waste spark. Some will also show hours of operation. Mine flashes the hours every one hundred hours. Perhaps your adjustment should be set to one pulse per revolution since we get a waste spark on the exhaust stroke. I think I paid 25 dollars for mine some years ago from Yamaha Sports Plaza. It was found in the generator section.

 

 

This is one like I got and it does have settings so you can set for one fire per revolution, two fire per revolution, I have it set for two fire per revolution so that fixes the dead fire. Like I said it says I'm turning 1000 RPMS at idle. What RPMS are you turning at different speeds?

 

Mike

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[MikeWa]

When we have a waste spark we get one ignition spark for each revolution of the crank instead of every other revolution. More like a two cycle engine. Some tachs can't compensate for this, some can. The one you have certainly lists as being compatible with the RSV so I do not know why it isn't working. The one I have is Yamaha part number 'Eng-meter-4C-01'. I don't recall if it is for a two cycle or four cycle or four cycle with a waste spark.

 

Mike

[Edbo]

When you say mine isn't working are you agreeing that it's not reading the right RPMS. That's what I'm trying to find out if it's on wrong setting, that's why I need to know how many RPMS the bike should be at idle and let's say at 50 or 60 mph.

[MikeWa]

Here is a chart.

 

Mike