Dyno Tuning

BA · October 21, 2009, 10:06:07 PM

Ran my bike on the dyno with the exhaust sniffer last night. 100% power run with no load showed a very lean condition between 2000 and 6500 rpm. The HP and torque curves were not very smooth and after closer inspection discovered my chain had some very tight spots, and lose spots (needs to be replaced). Then we ran steady state stepping up the rpm 1000 each time with a 25% braking load and it also showed it lean up to 6500 rpm, but idle was just a little rich. I'm going to pull the carbs this weekend and put in the 108 mains, leave the idle jets stock, and see what it does. My instructor thinks I may even need to go up one more step on the mains. Once I get idle and WOT jetted right, I'll see what needs to be done to the needle. This would be the best way to tune with the dynojet kit, but I'm going to see what can be done with jets and shims.

I'm also going to install a new chain and want suggestions for what type and where's the best place to get one.

roboto65 · October 21, 2009, 10:10:55 PM

I might try raising the needle first not saying the Main Jet would not help but the RPMs you are talking about are the needles fault if you were to lift it one more shim that would richen it thru that range IMHO..

TLRam1 · October 21, 2009, 11:35:31 PM

BA post up what your bike setup is now so people can see where you started.

Greg Cothern · October 22, 2009, 05:36:51 AM

YEP raise the needle before the mains. You can actually do this with them on the bike..

BA · October 22, 2009, 03:16:14 PM

OK, here's my starting point...

K&N Air Filter
Two 7/16" diameter holes on the rear plate of each stock muffler
Stock 40 idle jets
A/F screws turned out 2-3/4 turns
105 main jets
2 extra shims on each needle (3 total on each)

Peak numbers were 79 HP and 46 ft-lbs of torque (both at about 9K rpm).

Any suggestions on a new chain and the best/lowest price source? I've heard good things about the DID ZVM X ring.

BA · October 22, 2009, 03:18:46 PM

I will also be replacing the plugs and checking the valve clearance while I'm at it. And I really should sync the carbs before bringing it back to the dyno.

Charles S Otwell · October 22, 2009, 03:56:20 PM

QuotePeak numbers were 79 HP and 46 ft-lbs of torque (both at about 9K rpm).

Our web page Magna specs gives 78.2 hp @9,000 rpm and 48.2 ft lbs , sounds like your dead on.. What are you shooting for? It's my understanding that much more hp than that get's pretty expensive.

TLRam1 · October 22, 2009, 04:23:20 PM

Yes D.I.D. is pretty good stuff, seems most prefer that over RK, also read good things about Regina, can't remember on Tsubaki, no info on EK either.

I would think most poeple would say DID is a good chain for the money.

Good to post the start point as I don;t thonk many knew you already had a total of 3 shims on each needle.

BA · October 22, 2009, 07:44:40 PM

What I'm shooting for is the experience in operating the dyno and tuning the carbs the correct way by dialing in the correct A/F ratio through out the RPM range. I know with the CV carbs there is some give and take throughout the range, and if I see any HP gain from it all the better. I just want a properly tuned bike. We're also working on a couple single carburetor Harleys that are pretty simple, so I thought it would be cool to tackle the 4 carb metric bike. Next semester we get to work with EFI bikes and dialing in the tune by making changes to the MAP. When I'm finished with the class I not only will be able to operate the dyno confidently, I will be able to use it as a tuning tool. Anyone know anyplace in South Texas looking for a dyno operator?

Boy that DID x-ring chain is pricey. My stealer has one for $176. I'll take a look at it tomorrow when I pick up the new jets that I ordered.

Charles S Otwell · October 22, 2009, 07:56:34 PM

With as many bikes on the road as there are these days, sounds like an excellent opportunity, especially with so many riders being performance minded.

TLRam1 · October 22, 2009, 09:59:04 PM

Quote from: BA on October 22, 2009, 07:44:40 PM

Boy that DID x-ring chain is pricey. My stealer has one for $176. I'll take a look at it tomorrow when I pick up the new jets that I ordered.

I'm not into chains yet but I can have one to ya for 139 delivered if interested.

Capt. Howard · October 22, 2009, 10:07:59 PM

Quote from: TLRam1 on October 22, 2009, 09:59:04 PM
Quote from: BA on October 22, 2009, 07:44:40 PM

Boy that DID x-ring chain is pricey. My stealer has one for $176. I'll take a look at it tomorrow when I pick up the new jets that I ordered.

I'm not into chains yet but I can have one to ya for 139 delivered if interested.

Way to go Terry...you are a good salesman..and Smooth operator...That is a Good Price for sure!

BA · October 22, 2009, 10:51:28 PM

Terry,

Is that the ZVM2 series chain?

BA

TLRam1 · October 22, 2009, 11:00:14 PM

Quote from: BA on October 22, 2009, 10:51:28 PM
Terry,

Is that the ZVM2 series chain?

BA

Guess that info might help.

It's for the DID Gold X-Ring 530VM-120 link chain, tensile strength 9700, this is what I normally use, I will have to check on a zvm.

BA · October 22, 2009, 11:06:18 PM

Here's my plan...

Once I finish school, I plan to retire from my automotive engineering job (if I still have it) and move to South Texas and open my own motorcycle repair and service shop. I've completed two years of training and have already obtained my Master Motorcycle Mechanics license in Michigan. I signed up for the advance classes on dyno operations and tuning and will be done in the spring. They are also offering more classes on performance engine building, but I don't think I'll go that far. With unemployment in Michigan over 25%, it just isn't a great place to be living. I've been working side jobs on motorcycles out of my garage and am using the extra income to purchase specialty tools. I just hope there are enough riders in the valley that I can make a decent living. There's only a handful of shops there so I don't think I'll have any problems.

BA