Was getting 20mpg... will update you on this next tank

[DavidJRoberts]

Talked to my mechanic tonight.

He said if we move the clip it will make it run leaner and increase the mpgs. We could also go down to 104's from the 108's to increase the mpgs. He had already tried dialing the pilot screw (? can't remember) down to make it leaner in a quick attempt to see if that would help.

However, his concern on moving the clip or going to 104 main jets is that since I do go on the freeway often enough, I don't want to run the bike lean since it will be more be susceptible to running too hot and decreasing the engine life. If I just went around town I would be fine and I could increase my mpgs by doing this.

In fact, he leaned up the bike on Friday and I went on a 180 mile, mostly 80mph ride on Monday and just noticed this morning that there is now a large (3" diameter) blue spot on one of my pipes that wasn't there before. This is on the chrome cover/shield, not just the pipe! So, I know I need to put it back to where it was at least and not run lean again.

So, all that said, I suggested putting the stock pipes back on and adjusting the bike to run as best as possible like that with the jet kit still in there. When I bought the bike, the lad said I could take his cobra's with me and return the stocks if I wanted. He just wanted one set of pipes back and didn't care which ones. So I took both sets, the ones on the bike (stock) and his cobra's. So it's not like I went out and spent $500 on these, they were a swappable part for no extra cost. I just liked the sound I'd prefer to get 30mpg at least than have a louder bike, though.

Does all this sound right? My mechanic came highly recommended and said everything you had mentioned on this forum. He works on competition bikes (xc) and street bikes. Here's his site, you can see him doing those crazy large superman jumps on his xc bike (pictures)  http://www.mmmechanics.net/

[Magniac]

To my knowledge, CA emissions equipment give the same power and fuel economy as 49-state bikes.

[DavidJRoberts]

My mechanics going to pick the bike up on Saturday morning.

Unless I hear otherwise or find something new out, I think I'm going to have him put the stocks back on, leave the jet kit in there and make it run as best as possible with that set up. The jet kit should solve the 5k rpm hesitation since it's similar to adding a shim, right? His work is under his warranty so it won't cost anything more to have him jet it correctly. And like I said, the pipes were a freebie option when I bought the bike, I can just return them.

The bike has a little more hp with these high flow pipes but the almost stock setup (now just k&N and jet kit) will be just fine, I'm sure. 20mpg isn't much fun with this small tank and I'm not about to get spend money on larger tank... yet.

Was there anything else that you would try before doing this?

[Charles S Otwell]

The bike has a little more hp with these high flow pipes but the almost stock setup (now just k&N and jet kit) will be just fine, I'm sure

Hard to tell, even with high flow pipes HP gain has been debatable, I think a few have even seen a loss. Power or mpg  never was a problem with my wife's stock Magna, I hope the drag pipes I just put on it are not going to cause me a problem with her mpg or the way it runs. I Sure hope you get your Magan running up to it's potential with out too much trouble..

[TLRam1]

On my initial install of the Cobra Stage 1 kit to what looked correct on the Cobra instruction paper, I was getting 22mpg. I was also blowing out plenty of black smoke at full throttle.  Moving the clips on the needles up one notch corrected that problem.  I also have Cobra pipes and a K&N filter.

Busy lately and I have not visited the forum, thought Greg might show up, maybe busy also or out-of-pocket.

David,

As seen in the above post you should be able to work this out and keep the pipes you like. Just referencing Cobra pipes, many here have those and do not have an issue with MPG like you are experiencing but most do not have the Cobra Jet kit either.  Still I believe it's not your pipes but the carb tuning that is off. I have not used this kit before as someone stated the Jets are different, I have a Mukuni Hex Conversion to Round Jets Charts but that is it.

If you decide to go back to stock pipes, the ends can be drilled for better sound we can get into with photos another time if you wish and a forum member shot video w/sound of his.

I hear what you are saying about your mechanic...not every mechanic can be an expert on all bikes and types of setups, that takes trial and error. No disrespect to the mechanic you choose but most would know if you went from 40 MPG to 20 MPG on minor tuning something is AWOL. The comment on leaning the bike out is not valid.

However, his concern on moving the clip or going to 104 main jets is that since I do go on the freeway often enough, I don't want to run the bike lean since it will be more be susceptible to running too hot and decreasing the engine life. If I just went around town I would be fine and I could increase my mpgs by doing this.

This is not what we are doing, leaning the bike out to proper air-fuel ratio is not going to hurt it, that will make it run as it is intended. I don't know what the 104-108 jet equates to so unable to offer any help.

Strange why you have bluing on your head pipe as you should be rich, something is amiss, if you idled for a while and your pilot circuit was turned lean it would cause that. Your pilot screw should be at a minimum 2 1/2 turns out, more like IIRC 2 7/8's -3 1/4 turns out.


Write down your settings you know the carbs are at, I have not had the time to re-read what you wrote thoroughly and give Cobra a call Friday with what is happening and your settings.  

I called them for a customer once, the guy who answered was helpful, get there opinion and post back up if you have time. Ask how those jets equate to the stock jet sizes also David.

Cobra's number - (714) 692-8180 - CA Time

I could write more David but I want to keep this simple and easy.  I did not proof read my post...could be all messed up.

[DavidJRoberts]

Yeah, I think it was running either proper or slightly rich before he tightened the pilot screw last Friday. I had previously gone on a few 2-hr rides and it ran really good except for the mpgs. It now seems like it's running hotter than it should and the large blue spot from the single 180 mile trip I guess attests to that.

Well, I like the loud pipes but I'm not married to them, especially since I didn't pay for them! It's my daily rider and I'm not sure my neighbors appreciate them when I leave or arrive at o-dark-thirty since my apartment carport shares its wall with their patio and the sound reverbs big time, hehe. I start up and get out quickly though, no revving, that'd just be... well, no comment hehe.

Another factor for me is that this bike can't really take up much of my time or money... The mrs finally came around to me getting a bike (after years!) but our financial focus is on getting an emergency fund finished (since we're now debt free after hard work!) and our focus for our precious free time is on our family. So I don't want to spend too much time or money on the bike since it's not nearly as important as the other things in our lives. So I think I'll put the stocks back on and make sure he syncs and jets the the carbs well and hopefully that'll be it. Well, until something else happens! I'm just happy harry to even have one! It's my only wheels too so best take care of it!

Thanks for the Cobra number. I had called them before I got the kit and asked them about this stuff. They recommended what he did. I had also called dynojet and a local Honda dealership and they all recommended the same setup, except that the Honda guy recommended I stay 100% stock, hehe.

I wish I knew more detailed answered to the questions but hopefully this will get resolved this weekend.

[Charles S Otwell]

I had posted earlier that I had changed the exhaust on my wife's Magna to drag pipes and was not sure what would happen to the mpg She was getting with everything stock. We took a quick trip to Jefferson this afternoon for a sandwich at Auntie Skinners and then back home. Our trip was 114 miles and she used 2.8 gallons (40.7 mpg) this was not however an average run, Brenda hasn't had a chance to ride in a while, and was a little wound up. Hwy 59 from Texarkana to Linden is extra wide four lane with long straight stretches and sweeping curves, Linden to Jefferson is almost as good. With the exception of Atlanta and Linden and riding around in Jefferson we run 70 to 85 out on the highway. I not sure what got into my wife coming home but we were running around eighty when she blew past me, by the time I caught up we were running about 110 when we crossed Sulfur  River bridge. My point is she lost about 9 mpg over what she has been getting, but I'm not sure todays ride would fall under normal or average for checking gas mileage.  As far as I'm concerned nothing below 40 mpg would be acceptable.. Just my opinion. As far as those of you who think I'm being less than truthful, well your welcome to your opinion, so knock your selves out ..

[DavidJRoberts]

I had posted earlier that I had changed the exhaust on my wife's Magna to drag pipes and was not sure what would happen to the mpg She was getting with everything stock. We took a quick trip to Jefferson this afternoon for a sandwich at Auntie Skinners and then back home. Our trip was 114 miles and she used 2.8 gallons (40.7 mpg) this was not however an average run, Brenda hasn't had a chance to ride in a while, and was a little wound up. Hwy 59 from Texarkana to Linden is extra wide four lane with long straight stretches and sweeping curves, Linden to Jefferson is almost as good. With the exception of Atlanta and Linden and riding around in Jefferson we run 70 to 85 out on the highway. I not sure what got into my wife coming home but we were running around eighty when she blew past me, by the time I caught up we were running about 110 when we crossed Sulfur  River bridge. My point is she lost about 9 mpg over what she has been getting, but I'm not sure todays ride would fall under normal or average for checking gas mileage.  As far as I'm concerned nothing below 40 mpg would be acceptable.. Just my opinion. As far as those of you who think I'm being less than truthful, well your welcome to your opinion, so knock your selves out ..

Thanks Charles, did you adjust the jet sizes (main or idle) or do anything apart from swap out the pipes? Do you have a K&N filter in that bike? I have a K&N filter in mine and wasn't able to get it above 24mpg without it going too lean. Seems like there's just a ton of air going in and lots going out and the amount of petrol it takes to keep a proper balance brings the mpgs down considerably. We couldn't get the mpgs above 30 with my setup and when it went on the lean side I got a large, deep blue patch on my exhaust from a single 180m ride.

The bike had sat a little so we had to do an acid wash in the tank and he cleaned the carbs too. Would there be any reason associated with this for me to get such poor mpgs with cobra's and k&n with jet kit? I trust the carbs are synced properly. He's a very experienced mechanic that works on competition bikes too.

Anyroad, get the bike back on Wednesday and we'll see where we're at! Thanks for all the input, it's been a good educational process for me. Appreciate the help.

[TLRam1]

David,

One of my Magna's has Cobra pipes, the one in the photo, K&N, jetted carbs (not the Cobra Jet kit) but shimmed with 105's and I avg 38 MPG.

I was wondering where you were at with these, I was busy with work and did not check here as often as I wanted to see what you decided.

[Charles S Otwell]

Thanks Charles, did you adjust the jet sizes (main or idle) or do anything apart from swap out the pipes?

No I haven't changed anything else, it still has the stock air filter and as far as I know everything was stock when I bought it. I've only run a can of Sea Foam thru it a couple times, and only when I knew I would use the full tank in a days time. I sure hope you get your problem solved..-+

[DavidJRoberts]

Thanks Charles, did you adjust the jet sizes (main or idle) or do anything apart from swap out the pipes?

No I haven't changed anything else, it still has the stock air filter and as far as I know everything was stock when I bought it. I've only run a can of Sea Foam thru it a couple times, and only when I knew I would use the full tank in a days time. I sure hope you get your problem solved..-+

I ran a full can through it on Friday when I knew I was going to use 2 tanks. I put in a half a can for each full tank. It increased mpg's to 22 from 18-20. I wanted to run it through anyway since it's 16 years old. But who knows, maybe it ran better with that in it? I doubt it! It felt a little rougher and sounded different too while it was in there. I think I gave it a strong mix, just my style. I didn't see any white smoke. I had already had the carbs cleaned but I had this hanging around and wondered if it would clean anything else on its way through the engine!

I get the bike back on Wednesday. It will have stock pipes on it and will resynced again but I'll keep the k&n and jet kit in there. He may decrease the size of the jets now, not sure. I just know he's not going to want to work on it again under his own warranty (from a profit viewpoint) so he'll get it right! Perhaps I'll drill a hole or two into the stocks later or take out the baffles but that's another subject and another time! I'm ready to move on from the pipes for a while now!

[MarylandMagnav45]

Thanks Charles, did you adjust the jet sizes (main or idle) or do anything apart from swap out the pipes?

No I haven't changed anything else, it still has the stock air filter and as far as I know everything was stock when I bought it. I've only run a can of Sea Foam thru it a couple times, and only when I knew I would use the full tank in a days time. I sure hope you get your problem solved..-+

I ran a full can through it on Friday when I knew I was going to use 2 tanks. I put in a half a can for each full tank. It increased mpg's to 22 from 18-20. I wanted to run it through anyway since it's 16 years old. But who knows, maybe it ran better with that in it? I doubt it! It felt a little rougher and sounded different too while it was in there. I think I gave it a strong mix, just my style. I didn't see any white smoke. I had already had the carbs cleaned but I had this hanging around and wondered if it would clean anything else on its way through the engine!

I get the bike back on Wednesday. It will have stock pipes on it and will resynced again but I'll keep the k&n and jet kit in there. He may decrease the size of the jets now, not sure. I just know he's not going to want to work on it again under his own warranty (from a profit viewpoint) so he'll get it right! Perhaps I'll drill a hole or two into the stocks later or take out the baffles but that's another subject and another time! I'm ready to move on from the pipes for a while now!

Switch mechanics...and bring your bike back to stock...everything.

that's what i would do.

[TLRam1]

Switch mechanics...and bring your bike back to stock...everything.

that's what i would do.

The voice of reason, you should of replied as post #2 and we could have eliminated 2 pages of energy!

[MarylandMagnav45]

Switch mechanics...and bring your bike back to stock...everything.

that's what i would do.

The voice of reason, you should of replied as post #2 and we could have eliminated 2 pages of energy!

LOL.   

Those 2 pages are full of years of skill of deciphering problems and figuring them out.

My 2 cents come from frustration, inexperience, and problems yet to be solved .

My bike was a lot worse than his before I spent $2500 putting it back into "good shape".

[Lurkin]

Switch mechanics...and bring your bike back to stock...everything.

that's what i would do.

But with the Dynajet carb kit, you can't bring it back to stock due to the drilled slides....  Without a very large expense anyway.