Questions ...

[MaxMidnight]

I'm leaning toward carbs....a plug chop is a good place to start. 4th gear @ 4k go wot to red-line and hit the kill switch.QUOTE]

Quickest way to assess what is happening would be to get a baseline run on a dyno.

That said, I agree that a plug chop will help you decide if it is a rich or lean problem BUT given that it at the high end of the rev range that you have the issue then you would need to cut the motor at 9K so that you can assess the mixture at that RPM.

By all means do it at 4K but that would indicate the fuelling of the needle not the main jet.

One other point - you are assuming that the rev counter is accurate. It may under read in which case you are possibly just feeling the power dropping off as would be expected.

Is the air cleaner in good condition i.e. clean?

Finally how often does Mrs_M take it to those revs?
If this tends to be a rare occurrence then you are only giving yourself a job that needn't be done (I'm sure she could find you other work if you asked her... :no no no

 

[sdt354]

No....but, after searching this forum, I saw a post on that. i may break the carbs down again and do that adjustment tonight.

I hope you do an external float check before breaking down the carbs for a float adjustment. You may not need to take them off. And, it's the most accurate way too check them.
Steve-o

 

[cgswss]

Just an FYI... The way I do plug chops is to take the bike up at WOT thru the gears then while at top RPM Pull in the clutch and turn off the engine. The Important thing is to coast down and don't let the engine run or turn over, Another way to do it would be to just leave the bike in 2nd gear and run about 1/4 mile with the engine just off the rev limiter (or in your case where the engine stops pulling. Just as a quick check, take the bike out and note how many rpms it is reading at what speeds. we can tell you what RPMs they should be so you have an idea if your tach is correct. Maybe drive along in 2nd at 8000 and tell use how fast the bike is going- I'm kinda laid up right now, but I'm sure someone could jump on their bike and see what the rpm should be at 8000 in 2nd.

The problem you always have is that you don't know what the PO did to the bike. He may have read some where that if you run a #51 drill thru the main jet you will get 150hp on the internet and now you have main jets that are 3 sizes to big for a stock motor. Or he may have used welding torch tip cleaners to "clean out" his jet and in the process of sawing back and fort with then opened up the main jets so the bike is way too rich.

Do a plug chop so we can eliminate some of the possibilities.

 

[Mrs_Max]

Just did a fuel chop. Plug base rings are black. Rich condition looks like. I backed the air mixture screws to 1 3/4 turns and ran it. Helped a little. She wants to ride for the rest of the day since it's so nice out. I'm going to leave it alone so she can get her Max fix. Lol. I will get back on it later today. Much thanks, guys.

 

[srk468]

Plugs are exceptionally hard to read on these bikes, I'm a gearhead and have been dealing with 600+hp engines since my early 20's and I was getting nowhere fast on my bike until I did some research on here and installed a wideband O2 sensor and realized I was way rich and to be honest probably 65% or better of the guys on this site are rich too. Every bike is different but if you look at other people's altitudes and setups you can get a real good idea where to start but you'll never get it perfect for all conditions because they are just carburetors... I have a Kerker 4 into 1 and a Morley jet kit at about 800' above sea level and with stock mains I was rich 11.8-12.1 on the wideband but if you did a plug chop it looked lean... I have since modified my airbox a little more and got it better, still waiting on some more track time to see if it did help (we don't ride or race dyno's) but I'm confident it did.. Last year I went 11.4's and I weighed 293lbs in my race gear so I'm a bigger guy and if I let one of my smaller friends race it I'm sure it would've went 10's... All I'm saying is get ahold of Sean Morley and he will really help point you in the right direction because he's messed with about every type of set up there is and he can really help you sort things out so you'll wanna take his advice...

Sent from my ADR6400L using Tapatalk 2

 

[Mrs_Max]

I'm back driving OTR. I will be back to work on my wife's vmax this weekend.

 

[Mrs_Max]

Problem resolved. New battery put on bike and pulls through high RPM just fine now. Thank you all for your help and suggestions.

 

[dannymax]

Problem resolved. New battery put on bike and pulls through high RPM just fine now. Thank you all for your help and suggestions.

Well I'll be darned.....wouldda guessed for quite awhile before coming up with that.....good catch, glad you found it! :clapping:

 

[jfeagins]

Bike running/charging correctly SHOULD provide plenty of voltage w/o a battery to run the bike -especially up in the higher RPM ranges. If it runs down low, it should also run up high. I'm betting you got a charging problem going on as well as needing that new battery. Just sayin....

 

[Mrs_Max]

Bike running/charging correctly SHOULD provide plenty of voltage w/o a battery to run the bike -especially up in the higher RPM ranges. If it runs down low, it should also run up high. I'm betting you got a charging problem going on as well as needing that new battery. Just sayin....

I will run tests at off, idle & 2500 rpm with my voltmeter when I get back home to see how the charging system is acting. I was just happy that the high rpm problem had disappeared. ...Lol. Thanks for the tip.