1998 phazer ii high idle problem

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Dangerous Dan

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1998 phazer ii high idle problem (problem resolved)

I bought phazer this year with 300 + miles on it. Currently my problem is the idle is too high on it. It is running at 2600 RPM's instead of the 1500-1600 rpms. At such a high rpm the clutch is just starting to engage. Simple adjustments I have done so far include turning the idle screw. I have turned it back to the point where the TORS kills the engine. Second I have adjusted needle valves, which had no effect. I have sprayed the carb boots and pto seal with starting fluid to check for air leaks, no change there. I have engaged the chock to give me a rough idea where my fuel mixture is at (engine died as expected). Dropped the chock plungers to make sure chock curcuit is completely closed in off position. Made sure caps are installed in syncronizor ports on carb bodies. Slacked up the throttle cable to make sure butter fly can completely close (This model year has only one throttle cable). Pulled the carbs, cleaned and replaced any fuel mixing parts that looked questionable (so far pilot jets). Checked to make sure butter flies are completely closed by eye.

I have run out of ideas to try on this machine. Not sure if I am missing something with these carb's as compared to the round slides.

Any help would be appreciated.

Also, I have taken a fine tooth comb over this machine to make sure everything is in good condition.
 
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My guess is that is actually running lean a bit at idle.

Things to check . . . (this is the stock butterfly carbs, right?)

  • Pilot Circuit completely open. Did you check the complete pilot circuit with carb cleaner spray including the air jet?
  • Throttle valves not closing properly. Did you measure the height while at idle stop?
  • Rubber plugs in right holes inside carb bowls. Did you verify that these are in the right holes for your year and model?
  • Carbs not synchronized. Compare height of both throttle valves at idle stop.

If everything checks out, then loosen your throttle cable and see if the idle stop screw will back off any allowing the throttle valves to close a little more.

Set idle speed and mixture first, and then set throttle cable slack.
 
if your going with new carbs you might as well go with flatslide carbs .... i would think you have a crankseal out.. i had a motor do that to me... run the motor on a stand pin it and keep WOT for 20 seconds and turn the key off and keep the throttle open still. hit the brake stop it quickly. and once its all over release the throttle and check the plugs...one is lean i can hear it...lol
 
Ding

Yes these are the stock butter fly carb's.

I am about ready to recheck some of the things you mentioned.
Pilot Circuit.

Throttle valves (Butter flies) were check by eye. Both closed when carbs were pulled from engine. Is there a measured height at the idle stop? If so it is not in my owners manual.

Regarding rubber plugs, I do not have any literature to verify the exact location for all the plugs. I do know that I did reinstall a rubber plug over the pilot jet in each carb. The second set of plugs was reinstalled in the same location the previous owner had placed them.

Carb not synchronized. I did a visual inspection of the throttle valves (Butter Flies) both appear to be close equally. But have not ruled this out as a possible problem.


Smkin _Exciter_420

I am staying with the stock carb's.

Also, I just came in from doing a spark plug check since the engine has been running at high idle. I was thinking if air was being sucked in from a bad seal (mag or pto) or bad carb boot, my plugs should be coming out light gray or white. They are not . The plugs are coming out black on the wet side (rich gas mixture). So I do not see an issue with air leaks and am leading more toward carburation at this time.

Thanks for the input guys.

Will check back in with my findings.
 
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Well just finished cleaning the carbs for the second time today. Paying close attention to the butterfly closed position in both carbs, they defiantly look to be in the same position. Removed all fuel metering components including the air jet at entrant of the carb barrel and let them soak in acitone. While the components were soaking, I cleaned the carb bodies with break cleaner and blew all the curcuits out with compressed air. Put everything back together again including the rubber plugs in right tubes.

Drum roll please.

Same results idles at too high an rpm.

Stumped :o|
 
Here is the parts diagram for the 1998 Phazer SS (shows which holes have plugs)
 

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  • 1998 Phazer Carb Parts Diagram.gif
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Did you loosen up the throttle cable? You are sure there aren't any air leaks?

I am at a loss with seeing it then.
 
try the air leak with propane... and you wont be able to check a crank seal with all the air being moved around with the clutch and magnito... i bet thats it..
 
Use a mirror and a light and check to see if the butterflies are open with the carbs installed.
 
i have a 86 phazer & when trying too dialling it in i found that 2 turns on the low speeds out was the sweet spot when warmed up.hope this helps too.& how many miles r onit?.
 
Well gentlemen. I have ruled out the carbs. Just swapped out carbs from my machine with ones from my brothers working machine. Same results high idle.

We also pinched off the vacuum line to the fuel pump thinking there is a pin hole leak in the diaphram. Again no change.

I am to the point of throwing crap to the wall and seeing if it will stick. That is putting new mag and pto seals in for no logical reason. Keep in mind there is only 325 miles on this thing.

Also, we removed the TORS switch thinking it might be impeding butterfly closure. Again no change.

Excuse me, I now have stop my brother from hitting his head against the wall on this problem that does not make any sense.
 
Spray the starting fluid everywhere if you havent done that. All around the boost bottle, underneath the carbs and intakes, around the cylinder base gaskets.

Pull off the spark plug wires individually and start it and see how it runs on each cylinder, that might be helpful in narrowing it down. It might be best to remove the boost bottle and plug the holes when you do that - or try it both ways.

Possibly a choke plunger is not seating fully or the sealing surface is damaged. If there is something causing one to hang up - corrosion, a burr etc. or it will not seal at the seat, it could do it on both sets of carbs.
 
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PZ1

Tried the chock plunger idea, still no change.

I have resorted breaking the entire engine down and replacing all the seals at this point.

If someone can provide me with the torque specs for the following that would be great.

Crank case bolts

Jug bolts

Flywheel nut

Primary clutch bolt.

If this does not take care of the problem it is going into the shop.
 
In foot-pounds

Crank case bolts first 9.4
final 15

Jug bolts -Head bolt 11
nut 20

Flywheel nut 61

Primary clutch bolt. first 87 - loosen, then to 43



If you give up you can sell it to me !
.
 
PZ 1 said:
In foot-pounds

Crank case bolts first 9.4
final 15

Jug bolts -Head bolt 11
nut 20

Flywheel nut 61

Primary clutch bolt. first 87 - loosen, then to 43



If you give up you can sell it to me !
.
Click to expand...


PZ 1

Thanks for information.

Regarding selling it, you are number five in line. :p
 
Well gents.

The people who said it was the seals were right. But, for those including myself who thought spraying starting fluid on the pto side would reveal a leak if it was bad are wrong in this case. Found out during the disassembly process yamaha has a secondary housing before the pto seal that contains the gears for powering the oil injection pump. Spray all you want as I did, but the starting fluid is not going to get through unless that secondary housing seal is bad also.

I also discovered the crankcase was 1/8~1/4 filled with gas that sat and turned to varnish. The varnish buildup gummed up the crank bearings, which is currently being cleaned in acitone. Crank bearings were not moving freely.

Both pto and mag seals were destroyed somehow by the gas in the crankcase. They were not hard, but real soft and gummy.

This could have been a very expensive fix.

Looking to have her back together by this weekend. Will post back with final results.
 
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