Hi, like topic say iam lost here. dunno what to do. problem is

My bike is a VTR 1000F from 1997. SC36 stel number says JH2SC36A2VM001529

I bought a pair of Leo Vince exhaust.

When i put the exhaust on, the bike run fine, the db killer wass in. I took the DB killers out, and the problem started. it ran as i wass missing fuel, and the plugs wass white as hell.

I put a new main jet in, Front 180. rear 190. the needel is raised with 2 washers they are 0.60 each, pilot screw are front 2.5, rear 3.5.
The bike run fine with this setup. also at high speed (230+) i have a standard air filter in it.

The front plug are good nice color. brownís. the rear is grey/white. more white the gray it looks like. when i take the speed off the bike, its says a noise from the exhauset, like it farts. puf puf puf.

I tryed raise the pilot screw a bit more, and then the puf puf goes away, but then i have problem a high speed arround 190-200 when it have to work., its like it aint getting enouch fuel, or maybe to mouch ?

I have cleaned the carb, and re synced them, still the same. also new plugs in it.

any ideas or advice would save my day

Thx. Jens

 

i think you are saying ---- it was running fine but you were getting some gurgling/small backfire when you decelerate? If that was all it probably still was a bit lean. If you are already 2.5-3.5 turns out on the a/f screw you could go up a size on the pilot jet - many have put in 48's with good results. But that is really just the lower rpm stuff. if you are also having trouble at higher speed and you stll have a white rear plug, you might try just raising the rear needle a bit more or leaving the needle where it is and just increasing the rear main jet. Its hard to know without knowing exactly how it runs in mid range and top end with a load on it. I am thinking if you just change the rear main you will get more fuel all through the range and it might improve things. Those are my thoughts - go step wise and try to figure out where its not running best.

 

You might also want to check for a vacumm leak on the rear cyl. The thing that caught my eye was the size of the mains you are running. The normal set up is to go one size larger on the rear carb. so if you are running a 180 in the front you should be fine with a 182 in the rear.

So the first step would be to check the isolator and them the line that operates the petcock and also the diaphragm in the petcock. After they are all known good, check the rest of the vacuum ports on the carbs and then go from there.

 

Hej jens jeg har samme problem efter at have smidt scorpion Potter på min firestorm. Den kører som om den har alt for mager blandning. Nogen gange går den helt i stå eller kun på en cyl. Jeg vil have den dyset ind nu på rullefelt for jeg magter ikke at det ikke spiller. Jeg tror problemet er at potterne flower meget bedre og at den defor kræver mere benzin.. Vh Flemming

 

+1 I'll have to agree with that. hahaha

 

put another washer in the rear or jump up the jet one size. If you jump a jet size you may want to remove the currently installed washer. Superhawks are great. They remind me so much of my MG when I had it. Drive for two - wrench for four.

 

Si, Claro. Todos estan de acuerdo en que es asi!

 

Do Firestorms have a PAIR system? If so, disable that and put it back to where it was running well.

 

I found out in my exhaust system underneth where all the pipes go together. in the buttom of it, there is a small hole. looks like its factory made. like if there are water in the pipes. so it can run out. maybe that could cause the problem ?
i mean when i take the throttel off, it can take air in that way, so if there are fuel left unburned, i could caouse the pof pof sound.

Any one have that also ?

jens.

 

Plug the hoses that comes from the center of the valve covers, not the breathers, but the PAIR system.
But a well tuned carb will fart a littlewill fart a little when well tuned since there is no high vacuum jet, the high vac is pulling more air trough the throttle and overload the idle circuit, you need to be too rich at idle to fix this, but if you can live with the rumble it should be fine.
Good job on the carb tuning so far.

 

The PAIR system, you mean where the exhausts are connecting to each other under the bike or ?

Jens.

 

NM found out what pair system is. and it aint on my model, so np there.

 

no, claro. Ba fraenda dagol. Ba fanabale el fungol! Bootan la bruta e bella. Ma ga si bella!

oh, e stutazit>

 

so far so good.

found a leek in the exhaust system, so the buf buf when gass off, is nearly gone. thx god.

the plugs looks good now. in gear 1-2-3 np there, when in 4 gear and i run it up until 9000 rpm, it "hang" dunno how to explain it on english. but feels like it aint getting fuel enouch, or maybe to mouch ?? when it starts on it, and i change to 5 gear and it goes under the 9k rpm, it runs fine again, again at 9k in 5 it do the same again, until i go to 6 gear. "cryes"

any suggestions !!!!!!!!

 

Check the fuel petcock diaphram for a small tear or and any small vacuum leaks in the lines. I've seen other threads about fuel cut off above 8000 rpm, and it seems like they all had torn diaphrams. You have really low vaccuum above 8000 rpm and that is when the little tear or vaccuum leak shows up in performance. When checking, it doesn't hurt to cut the last inch off all vaccuum lines and reconnect to get new mating surfaces.

I think that your carb synchronizing at 9000 rpm will be way off too with two jet sizes between cylinders, that could be effecting vaccuum as well.

 

Defined RPM hanging could be either too small mains, the plugs would be white, or simply one or both cams are off for some reason, like timing chain wear, improper alignment from valve adjust.

 

but mains are 180 front 190 rear, needel raised x2 0,60 each. with just normal airfilter, and open exhaust on, should that be enouch ?

Dont think it cams or chains, becouse until 9k rpm it runs smooth.

Also when it had factory exhausts on, there wass nothing wrong at all. all problems started with the new exhausts on.

 

I would go up one the jet size or raise needles to the last notch till you get it right. Air mixture? Also. set your TPS to 500ohm while you're in there. Experiment by removing air filter. Replace it with a piece of foam temporarily. Keep at it, you'll get it.

 

Any one know where to order main jets 200-205-210 and so on from, called every honda dealer in denmark, and no one could help me

 

If you are running a stock engine, with stock airfilter and slip-ons you really do NOT need anything that big... Start making a comprehensive list of what non factory parts you have, and we will figure it out, but a main jet at 200+ is no going to help...

 

exhaust is the only non factory on it. leo vince. air filter is also factory made.

iam checking fuel petcock diaphram now. going to change the one that goes to the fuel tank. also gonna inspect all diaphrams on the rear carb, that causes all the problems.

Front plugs is ok, so aint gonna work on front carb. rear plugs are starting to get brownish, but still also white. so that gonna be my main target.

atm rear jet is 190 with needel raised with 2 washers 0,60 each. screw is atm 3,5 out rear, and 3 front.

Gonna check fuel tank and see it enouch gas comes out to the rear carb.

 

Found a littel tiny leak in the gasoline hose, so changed it to a new one. had the carbs out to check the rubber hoses arround the carbs, np there, bran new. i resyncéd the carbs just to be sure.

Checked the gas tank, to be sure enouch gasoline comes out. everything ok also.

Cleared the air filter and air filer box. just to be sure.

tryed the trick with the choker, when its warm. when i pull it a bit out, it takes more rpm. if i pull it all the way out, it dies out, but start right away again.

Had it out for a spin. np in 1-2-3 gear again, as soon i hit 9k rpm, it stop working, "stalls" or what ever its called" then slip the gas and let it go under 9k, then it runs fine again.

Just pulled the sparks out, front looks fine, rear it gray/white. gray on one site of the plug, and white on the other side.

 

The plugs there are in are: DPR9EVX-9, same as in haynes manual. have run arorund 700 km.

I have some plugs called Iridium DPS9EIX-9 laying arround, they kind look the same, any one know if they fits, just to test em out.

 

Have you checked the diaphragm in the petcock yet?

 

i tested the diaphragm in the petcock, and its fine, also tested if there came gas out of it if i forsed it, all works fine.

 

lets say its still a air leak somwhere. what can i use to spray on to test with ?

 

Carb cleaner or Ether (starter fluid), spray it at suspect hoses while the bike is idling to see if the RPMs go up.

 

Actually going over the whole thread I see another place I'd start... Two things, one is an easy test item...

One... Disconnect/disable the sidestand switch... We recently had one member on the Swedish forum that more or less tore his whole bike apart cuz it wouldn't rev over 8k... His sidestand switch was faulty... Just remember not to start it in gear ride with the stand down while testing...

Two... you are saying you have washers on both carb needles... "two, each 0.60"... If that's two 0.60 washers on each needle, meaning 1,2 total on each needle, go take them out right now... You should not be above 0.60 on each carb... Then you need to swap out the main jets instead...

Also, to clarify... You are revving the bike to 9000+ rpm in 2-3 gear as well? And there is no problems then? Only if you do it in 4'th or 5'th? That's not logical... And I dare say impossible...

Seriously, a problem with the jetting and rpm range should be persistant across all gears... The carbs doesn't know or care what gear you are in...

 

i know it sounds strange, but 1-2-3 gear, there is no problems. thats how it is.
Going to try testing for air leaks with liqued.

cant see the washers should be a problems atm, no so long its going to lean. if it wass to rich, then ok, out with them.

gonna try to disabel the side stand switch, just in cast

 

Where in Denmark are you located?