Road Star Forum
Welcome, Guest
Please Login or Register.    Lost Password?
Re:HSR 42 Information
Go to bottom Post Reply Favoured: 16
TOPIC: Re:HSR 42 Information
#292198
DocShadow (Admin)
Hmmmm .... send beer
Admin
Posts: 18470
graph
User Online Now Click here to see the profile of this user
Gender: Male DocShadow's RoadStar Site Location: Ottawa, Ontario
Re:HSR 42 Information 4 Years ago  
Yes I'm running a #20 pilot jet. I'm assuming that as the pilot screw is almost all the way in that I should go up one step to a 22.5? That seems to be my main problem. Also getting a slight puffing on decel when it hits the lower revs, which I assume may be due to the lean pilot.

From the roll-off (WOT) test I think I'm OK with the 160 main so I'm leaving that one in. Right up to the rev limiter in 2nd .. no hesitation, good response.

The pump nozzle is a #70 and I'm getting a slight lag (not response) before it goes full bore .... at low revs, not at high revs. I also need to check where the squirt is aimed.

No backfiring in exhaust or airbox .... except when cold and I try to push it I get the lean backfire.

Running my BAK but it was tough to get on .. the rubber is a bit smaller than the intake on the 42.

Doc
 
Logged Logged  
 
  The administrator has disabled public write access.
#292202
DocShadow (Admin)
Hmmmm .... send beer
Admin
Posts: 18470
graph
User Online Now Click here to see the profile of this user
Gender: Male DocShadow's RoadStar Site Location: Ottawa, Ontario
Re:HSR 42 Information 4 Years ago  
erbman,

Like you, I have a Nemesis manifold. I don't like the way the stock rubber mates the carb to the manifold. It looks like the rubber is bunching up a bit at the carb side.

Do you remember what size radiator hose you used or are you gonna make me take it all apart to find out.

Thanks,

Doc
 
Logged Logged  
 
  The administrator has disabled public write access.
#292203
Erbman02 (User)
Platinum Boarder
Posts: 6613
graphgraph
User Online Now Click here to see the profile of this user
Re:HSR 42 Information 4 Years ago  
curt, is that filter use an off-set hole. hard to tell, and too tired to go to their site. lol never mind, I looked at site, lol Yeah, the 2.75 is what the K&N shows for 42 specific carbs, which is strange, bevause they say it would fit a 40mm carb such as the stocker, but that opening is way too big for the stocker, it is ideal for the 42 tho. but they are both only 3" h. so does that fit just a hair tight?
 
Logged Logged  
 
  The administrator has disabled public write access.
#292207
Erbman02 (User)
Platinum Boarder
Posts: 6613
graphgraph
User Online Now Click here to see the profile of this user
Re:HSR 42 Information 4 Years ago  
Doc, according to the manual if more than 1 turn in, go up in size, I if you go up 1 size (22.5), then to get the same idle rpm, turn out the pilot screw at least 1/2 turn from where you are now, no more than 3/4 turn. But if you are less than 1 turn out with the 20, then I would suggest the 25 pilot jet and 1 to 1.5 turns out from where you are now the slight lag could be because of too small pilot jet, and or the pump squirt is starting just off throttle, I re-set mine to start at throttle. everyone that I know of and who I have helped set-up the carb are using the 50. The 70 is just wasting gas in your mid-range, but you won't feel it by the seat of the pants, will see it on mpg's and by afr run. Sorry Doc, guess you're gonna have to go measure for a radiator hose, when I got mine, I had the carb in hand and he led me to the back and we test fit, or maybe I had the manifold in hand, been quite some time, but I think the od of the manifold is a touch bigger than the spigot of carb too. I got rid of the nemesis boot after 4 months of use, it split right at edge of clamp, would leak at idle, only riding, was a booger to find, since it would seal completely sitting at idle, was and had to be a visual to see the split, 1/3 the way around the boot. In fact a couple yrs ago, talking with someone in Tx, he was explaining about his symptoms, as he's going back to garage, told him to look at the boot, in hand, sure enough, same split like I had. After that, couldn't understand why Greg used such a weak boot found a boot, 44, 45mm will do fine
 
Logged Logged  
 
Last Edit: 2010/06/27 19:46 By Erbman02.
 
  The administrator has disabled public write access.
#292211
DocShadow (Admin)
Hmmmm .... send beer
Admin
Posts: 18470
graph
User Online Now Click here to see the profile of this user
Gender: Male DocShadow's RoadStar Site Location: Ottawa, Ontario
Re:HSR 42 Information 4 Years ago  
OK, I'll get the 25 and the 50.

I still think you should go out and measure your hose.

Doc
 
Logged Logged  
 
  The administrator has disabled public write access.
#292212
coot53 (User)
E=Mc1700
Platinum Boarder
Posts: 1610
graphgraph
User Online Now Click here to see the profile of this user
Gender: Male Location: Bethel NY Birthdate: 1953-03-19
Re:HSR 42 Information 4 Years ago  
Hi guys,
Been following this real close as I will be putting my 42 on in the next week or two. Have all the little goodies to deal with any jetting adjustments that may be required. btw j&p cycles carries mikuni jets and needles. They may not be the cheapest,but they ship pretty quick.

Coot
 
Logged Logged  
 
[img size=150][/img]
Cooter Scooter 06 Roadstar
  The administrator has disabled public write access.
#292255
Erbman02 (User)
Platinum Boarder
Posts: 6613
graphgraph
User Online Now Click here to see the profile of this user
Re:HSR 42 Information 4 Years ago  
Doc, I guess you missed my edit, found a piece in the house, 44, 45mm should do it
 
Logged Logged  
 
  The administrator has disabled public write access.
#292277
DocShadow (Admin)
Hmmmm .... send beer
Admin
Posts: 18470
graph
User Online Now Click here to see the profile of this user
Gender: Male DocShadow's RoadStar Site Location: Ottawa, Ontario
Re:HSR 42 Information 4 Years ago  
Yes, I did miss that.

I don't think the slight hesitation is the acc pump; it doesn't feel like that. When I'm running at lower rev and I give it throttle, it accelerates slowly and then when it hits a certain rev the bike takes off. Not dramatic but noticeable that the acceleration is not constant.

Thanks.

Doc
 
Logged Logged  
 
  The administrator has disabled public write access.
#292285
Erbman02 (User)
Platinum Boarder
Posts: 6613
graphgraph
User Online Now Click here to see the profile of this user
Re:HSR 42 Information 4 Years ago  
that pilot is too small, I know a few who use them, but they sure are missing the power. I've done a number of EGA runs, and too, on a completely sealed intake, and I'll put my last buck up that they are running about a 16afr at idle and somewhere close to 14 afr just off idle. granted, the roadie engine will still run lean, and quite lean to the point when you know it as well, but max tq occurs at 13.5 afr, but even going richer the tq is still flat, so why waste fuel for no benefit? and yes, you can run a wot at 14 afr, but at the expense of heat from friction at higher rpm's, and with detonation from too quick a roll-on, the 12.5 range is to help aid in cooling and prevent detonation at wot. I'm sure you heard the term "lean is mean" but, at the expense of possibly engine damage? The 42 is easier to dial the 3 ckts, guess I shouldn't say easier, but more so that each ckt can be dialed into the afr values that you want for each ckt.
 
Logged Logged  
 
  The administrator has disabled public write access.
#292301
DocShadow (Admin)
Hmmmm .... send beer
Admin
Posts: 18470
graph
User Online Now Click here to see the profile of this user
Gender: Male DocShadow's RoadStar Site Location: Ottawa, Ontario
Re:HSR 42 Information 4 Years ago  
I'm pretty sure you're right about the lean pilot ... I can sense it when starting the bike and the turned in pilot screw verifies it.

I'll if I can snag one locally (I doubt it) otherwise I'll have to get one shipped in. If perfectly drivable now but needs a long warmup time with the choke on ... something that I'm not to crazy about.

Thanks,

Doc
 
Logged Logged  
 
  The administrator has disabled public write access.
Go to top Post Reply
Powered by FireBoardget the latest posts directly to your desktop
...................................................................... ...................................................................... ...................................................................... ...................................................................... ...................................................................... ...................................................................... ...................................................................... ...................................................................... ...................................................................... -->
New Forum Posts




The Road Star Clinic is a collaborative community of riders who archive and publish user contributed technical data about Yamaha Road Star motorcycles.

We also sponsor the creation and support of other community websites similar to our own. Inquiries about availability of a website for your community can be submitted to us via any "Contact Us" option on the Clinic.

Copyright 2003-2007 Road Star Clinic and its respective authors. Road Star Clinic is sponsored by the folks at MLSHomeQuest.com.