Symptoms of overjetting

[ewalker302]

OK Heres what I Got Uni filter, FMF MegamaxII slipon, airbox lid on

I just replaced the stock jet with a 155 Dynomax main, and put in the dynomax needle clip in stock position.

It runs fine, no hesitation, no bogging, and no smoke.

The power seems to come in slower than before and at a higher rpm, but its hard to tell if I have gained any power with the bigger jet. It seemed peppier with the stock jet, but I know it was running lean because of the plug, and backfiring on decel.

If anyone has a similar setup, and is using Dynojets I would be interested to know what size main you are running.

Thanks
:bandit:

[cals400ex]

i don't kow what temperature or altitude your at, but i would say your big on the main. if the only mod you have is the slipon, i would say to use a 150 dynojet. the sizing on dynojet and keihin is different. a 155 keihin is about a 152 dynojet. i think the 150 dynojet is good for summer and a 152 dynojet is the one for winter. many times when you jet too big your bike will be doggy. i actually jetted too big after i got my pipe and it was slower with the aftermarket pipe on than when it was stock.

[ewalker302]

The Dynojet kit comes with 8 jets and the next size smaller than 155 is 146. I checked the DJ 146 against my stock 148, and it(DJ146) is a little bit larger.

BTW I live in Mississippi, no more than 500 ft above sea level, and it is HOT most of the year. I think I will try the 146DJ and see if i get some of the pep back.

Thanks
:bandit:

[ewalker302]

Update

I just installed the DJ 146 main and it runs great.

I tested the jets on a gravel logging road by my house.

With the DJ 155 main installed I would have to downshift out of fifth gear to break the rear end loose when cornering, the engine would not pick up revs when i got back into the gas after letting off to hit the turn.

After puttin in the DJ 146 which to my measurements is a little bit larger than the stock 148 jet, I could let off the throttle for 1-1/2 seconds when hitting the corner in fifth and it just rips when I get back on the gas, plenty of revs and a lot of improvement in seat of the pants feel.

Im posting this so that if anyone has similar mods maybe this will help if they think they have too large a main jet.

Also, it was super easy to swap jets by removing the nut on the bottom of the carb, and swapping the dynojets with a stubby flathead screwdiver.

Thanks
:bandit:

[Evan400ex]

I just got finished jetting my 400. I am using a DynoJet 170 main. Do you think that is to big of a main jet?? I go to pick up my LRD exhaust and rev box tomorrow so I won't be able to try it out until then. I will be running with a K&N, LRD full system, rev box, and airbox lid off. I think the LRD system requires a 165 main but I followed the instructions of the jet kit and put in the 170. If anyone else has the same setup let me know what size main you are running.

[ewalker302]

I think that will be too rich.
I would start out with a DJ160 with your mods and the lid off.
and I bet you will still have to drop another size. 170 is the biggest jet that the DJ kit comes with. I think you would have to do some internal mods before you would need that much jet.

I dont have any experience with the rev boxes, so I dont know if that will affect jetting or not?

I found out in the last few days that bigger isnt always better and sometimes its worse than what you started out with.
And you can swap the Djets in about 10 minutes if you need to test a few different sizes to get it tuned in.

:bandit:

[cals400ex]

yep, i say the dynojet 170 is too big. i am running a keihin 160 with full sparks x-6, no lid, uni filter, no choke. also, keihin sizes run a little smaller than the dynojets do. rev boxes should not effect jetting.

[hondarider2006]

I am running a 170, with the clip on the 4th position. It sputters a little at 1/8 throttle. I am going to get a 42 piolet jet here soon, and mess with my mixture screw. Hopefuly that will help my problem. It runs a little rich when I first start it, and the choke is on 1/2. Other than that, it runs like a beast. I am also using the dynojetkit. Look at my sig. for my mods.

[Evan400ex]

I did have a DJ 170 in mine too. I found out it was too rich so I dropped down to a DJ 160 and it runs like a beast. Try the 160 out and you should run alot better.