Honda Dylan 04 - Power Issues

Ok last update for tonight.

Acceleration is slower now than on the stock exhaust. It hits a wall at 50mph. Test was done on an A road near me that offers a 3 mile straight and fairly level section.

Is this related to jetting?

Pilot Jet size is different between a Dylan 02 and a 04 (38 and 35 respectively).
Main jet size is indeed 112.

Ive now found a few places that do CV/CVK Jets for Keihin Carbs.

What i dont get is do i need to upgrade both the pilot jet and the main jet?

 

The instructions are bad, I didnt use any brackets, slip the end can as far as it will go onto the pipe off the manifold and tighten the clip fully. Then use the exhaust bracket around the bottom of the end can and put the M8 bolt into the existing bolt hole nearest to the oil dipstick (pictured). I assume you used the cone shaped restrictors in it too. take them out to get the full potential like i have. Until M.O.T time of course. Do this and then let me know how your speed is after that because that'll be exactly like mine. Good luck.

 

make sure that the manifold is sealing proplerly as well because the manifold on my bike wasnt sealing right and it runined the performance.. on my bike i couldnt fully tighten the bracket holding it on without spacing it right out otherwise it kind of pulled front of the exhaust out of the manifold causing it to leak.. but that was mine, yours may seal fine depends on the pipe.. and as for jetting should not need to touch the pilot jet just the main jet, i would do what andy has said.. if it does not improve up jet it 2 - 4 sizes and see how it runs, if not maybe rollers.. but i see you have changed rollers?.. but not to sure as havent read all of this post

 

It's the beast!!! It's the best sounding exausts I've ever heard on a scooter and it looks the buisness too!!!

 

dream caster.. have you had a gilera ice?..

 

Ye I've got an ice.

 

Ok i'll remove the baffle/restrictor. With it in its worse than the stock exhaust. To get it back to that level probably needs some tweaking of the jets. :/

Also im planning on checking the mixture screw (have checked and tweaked the idle screw several times, but its like it changes back to bogging after a week), as it is getting to be a real pain in the ass to keep running from first startup. After it warms up its fine. At present the auto choke has definitely failed. It doesnt kick in anymore, so i have to rev it a little for 5-10 secs or it stalls.

Im tempted to up my pilot jet to the same as the 02 Dylan, also tempted to take the main jet to 115 (might order 118 as well in case i can go a bit further), which is one size bigger than it currently is (i think, as im kind of learning about different carbs and what jets fit them, the 115 was the first size after 112 that fitted a CV carb). After writing that i decided to go ahead and ordered 115 and 118 main jets. The Haynes manual suggests switching them wont be that hard.

Some of the 4stroke jetting guides ive read suggest some of my problems may well have been related to jetting, but its such a headf**k subject i cant really be sure.

In case anyone is interested, the links to what ive ordered. Hope they fit, but it says for Keihin CV carbs, so they should do.

http://www.ebay.co.uk/itm/Keihin-FC...31?pt=UK_Motorcycle_Parts&hash=item3a7034db87
http://www.ebay.co.uk/itm/Keihin-FC...49?pt=UK_Motorcycle_Parts&hash=item3cc1ee4ddd

 

yeah, if i was you i would do one jet at a time tho.. although it maybe a pain to keep taking carb apart at least you will know what jet has made the difference.. as jetting is all about little adjustments.. i would try 115 and see how it goes then do the pilot jet.. yeah its not to hard to switch just make sure you clean all the S*** out of your carb to keep it running good.. ahaa yeah jetting isnt great fun but can make a HUGE ! difference to your bike.. but just make sure you do one thing at a time and properly test is..

 

It will be fine I'm sure when the exhaust is on right, also check the exhaust manifold is tight (not overly tight though) as this will lose power if it is even slightly blowing. Mine stalls sometimes on first startup, but fire it up second time it's absolutely perfect. This problem will be gone soon. My auto choke is fine still. The only other thing I can think of is that I run my Dylan on high octane fuel. If you run yours on 95 octane (normal unleaded) you may well need to upjet to the next size. It's the only thing I can think of but it shouldn't really make a difference what octane fuel you fill up with.

 

I found this guide while wandering around the web. Looks to be aimed at motorcycles, but parts of it will probably apply to us as well.

http://www.duncanracing.com/TechCenter/KeihinCarbJetting.pdf

I tend to run mine on normal unleaded, as a lot of my problems started when i was using super. Nowadays i tend to run 1L Super to 3L Regular once in a while to keep the engine/carb clean (or a cap of redex when im lazy). But im not against running Super for a couple of weeks to see if that helps.

I always wondered if the breakdown of the ethanol in the fuel mixture caused some of the problems. Apparently within a week it starts to breakdown into water as the alcohol evaporates, and apparently the french stuff that has 20% ethanol breaks down even quicker. Not sure if this is bunkum, it came from a motorcycle mechanic i know.

I will give that company i ordered the jets from a ring and see if the 38 pilot they have will fit my carb, as it doesnt say it supports a CV carb, just a CVK.

Also gonna order some exhaust manifold gaskets i think.

 

Well today is a bad and sad day. My bike is in god knows what state. I've got a broken clavicle (collarbone).

Was enroute to work this morning, hit the usual gridlock, low speed filtering around the traffic when a black astra t-boned me at 20ish mph. I took the full impact on my left shoulder which is broken. Thank god i was wearing all the gear. The helmet is missing a chunk of poly carb where my head hit the road.

The bike is at minimum a cat c, mostly frontal damage. If it is a cat c i will see if i can buy it back off the insurance comp. I can repair it, from what i saw of it. Thankfully it landed on the trans/air side, so my exhaust is probably ok (priorities are right, the ambulance guy said i kept asking him if the exhaust was damaged, but i was off my face on entonox, and dont remember some stuff after it happened).

Cops wanted to charge the driver with drviing without due care, but ive told them i dont want her charged. We both learned something today. No need for courts and all that crap. Accidents happen and ive been expecting this or a drop ever since my cbt.

At the same time i wouldnt wish this on anyone. Breaking your collarbone fkin hurts. Got painkillers though. But off work for 6-8 weeks, which sucks the most. :/

So i will update you guys on things as they continue. Going to call the insurance company next, then they can sort it out. Wont be riding again for a while, but im alive and have relatively minor injuries, so i will be back in the future.

 

Man you have had a week of pure bad luck. Glad your not very seriously injured, get well soon and keep us updated.

 

hope you feel better soon.. got a feeling the next post we are gona see is from you in the project section lol.. hope your bike isnt to bad..

 

Going to get it back tomorrow, so will tell you what it looks like then.

 

Ok its recovered, and its not to bad. Seems to be mainly fairing damage and scrapes. Front forks and steering seems fine.

Will try and get pics tomorrow.

 

How's things going health and ped wise?

 

Still much the same. Bike is in the garage, not much to do until the solicitors get an engy to look at it. After that and once its all dealt with, it will take me about 2 hrs to fix it, if i can get the bits.

Health wise is a cocktail of co-codamol and tramadol.

Still in a load of pain. Hope none of you guys ever sample a broken collarbone, its an unpleasant injury. My left arm is essentially useless for the next 6-8 weeks.

 

Well I hope you get well soon. At least you'll be floating with the pigs in the sky for a little while on that cocktail. Post some pics of your broken bike so I can see what your going To be fixing poor Dylan.

 

Hope your feeling better, just came across this site with most parts for our scooter as I was looking for a big bore kit etc, so I thought it might interest you as it has jets and everything http://www.racingplanetusa.com/engi....html?sessID=82be082e006237bec26e674e4f06aa63