TPS Me too??

thehazmatguy · Post by **thehazmatguy** » Sat May 17, 2003 3:52 am

My patience is wearing thin...

I had a mechanic do a carb balance a month or two, and since then the bike idled kind of bad. The bike felt better otherwise, but the idle just wasn't right. I just figured something was a little off, I wasn't worried about it because I had a jet kit on the way. (I was waiting for the BMC air filter that never came, had to go with a K&N)

Last week the Dynojet jet kit was installed with a K&N air filter. Then the bike wouldn't idle. The mechanic chases down two broken choke screws at the base of the carbs. The choke needles won't stay seated, so thereâ€™s my problem. After waiting a week for Honda to find me some, I made my own. blah, blah, blah... now the choke works, and the choke needles stay seated.

My mechanic talks to a dyno guy, and he takes the carbs and does a few things. I rode the bike a couple of days, and I don't like it. Throttle response seems slower, and torque seems down, but horsepower seems up.

My mechanic and I take my bike to the dyno guy today. Air fuel ratio is spot on the entire way through the rev range. (I watched entire thing, and I got the print out.) The bike has 102 horses, and 63 ft/pds of torque. The torque peak occurs at about 3500 and trails down from there. Overall the torque curve is very flat, but compared to other dyno runs from other vtr's I have seen on the internet, something isn't right.

98 vtr1000, 35,000 miles
K&N air filter
DynoJet jet kit, 180 front 185 rear. 3.5 turns out, 5th clip on needle.
Wolf undertail slip on exhaust.
New plugs, adjusted valves last week.

Suggestions? Is the Wolf pipe not keeping up with the rest of the bike?

Thanks!

WayneM · Post by **WayneM** » Sat May 17, 2003 11:14 am

I can only give you a comparison against my bike;

2002 20k miles
Piper X air filter
Devil Cans

108bhp
72 lb/ft

Certainly looks like something is a miss. Shame about your location, I would have let you borrow my Devils to identify or eliminate the cans.

Sorry cant be any more help - an all knowing all seeing VTR God will no doubt be along shortly with some pearls of wisdom - Del/Al?

philsmith · Post by **philsmith** » Sat May 17, 2003 12:16 pm

Yes indeed, Honda quote 105bhp as stock (true or not?),
Mine has Dynojet, K&N, & Ixil pipes and made 107bhp the other week.
Hope you get it sorted
Phil.

fastfrank · Post by **fastfrank** » Sat May 17, 2003 11:12 pm

My 1999 spec has 18000 miles
Scorpion high level race cans
Std filter (new) & std carbs
Dyno 109.3 hp @ 9184 rpm & 9.6kgm @ 6910 rpm

I enquired about a K&N jet and was told that they only had a 50% success rate when fitted!

I assume that means fitting one could make things worse?

thehazmatguy · Post by **thehazmatguy** » Tue May 20, 2003 6:33 am

update for those that are curious:

Tested the TPS today. got 4.87 ohms at almost 90 degrees F. (Tested at ICM per Honda manual).

I tested the resistance at varied throttle positions. It worked just like the manual said it should.

I also tested the voltage at the TPS connector, and that was just under 5 volts.

Every test for the TPS was in factory spec. I even changed out the ICM for another one I got from an Ebay purchase. I still have a hunting idle, and it will even backfire through the carb hard enough to make the bike quit while wiating for a traffic light to change.

Is it possible for the timing to be off? I think I will start to test the coils, plug wires, and maybe the plugs. Maybe it is an ignition thing?

delmeekc · Post by **delmeekc** » Tue May 20, 2003 9:17 am

I know it's hassle but try using the standard main jets and put the clips on position #4 and not #5. It could be too rich and this will effect the idle. When it was on the dyno did they do a short shift run to check the needle settings because it will be on the needles for 90% of most peoples riding.

You may also find changing the pilot jets would help to sort out the idle. this will not effect the way the bike runs once on the move but can really help the idle and 1/8 throttle riding.

The main jet sizes and needle position will effect the idle.

Another thing to check it that the Air Filter is not over oiled, years ago I over oiled a K&N and was only getting 80 rwhp, I even paid a shop to find the problem. They had given up and then thought what the heck and run it up without the filter, sorted.

Del.

thehazmatguy · Post by **thehazmatguy** » Wed May 21, 2003 5:25 am

Thank you for the help.

If the bike was running rich at idle, wouldn't that show on the dyno? He let it idle for a while, and even though the idle wasn't steady the "sniffer" showed a good range, not lean and not rich.

The hunting idle is almost cyclical. What I mean is that it goes up, then down, almost in rythem. Kind of like the idle surges automatically.

I am waiting for the Honda made choke cables as my next step. I plan on testing various ignition parts in the mean time. Is it possible that the timing could be so far off that it wouldn't idle right? The Honda manual tells how to check it, but not how to adjust it.

Thanks again for your help.

delmeekc · Post by **delmeekc** » Wed May 21, 2003 11:55 am

You can't adjust the standard ignition, as the pickup is static in the clutch cover and the rotor on the crank is keyed to the crank.

I really think it's carbs, have you also checked that the floats in the bowls work ok and that the needle valves actually seat properly and shut off the fuel when needed.

I know is a pain in the butt but I would do the main jet and needle clip position thing first.

Del.

VTR1000.ORG

TPS Me too??

TPS Me too??

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