Question-------------------------
Followup To
Question -
I just got a '91 Suzuki 400 Bandit with variable valve in a trade. It is an overseas model with a speedo in KPH. The local Suzuki mechanic has had no luck in getting the bike to idle correctly or run well. He's checked carb balance and jetting, valve clearance, vacume, everything he can think of. I've heard that some of the 400's had a problem with the black box. Could this cause the problems this bike has?
Answer -
Hi Kent,
Yes, the control module could play part in the symptoms, though I suspect other causes.
Can you describe the idle and running problems in more detail? Also, describe the appearance of the spark plugs to me. Remember which cylinder each plug is removed from.
Iclude your email address as requested. I return tech files via email.
Respectfully,
Mark Shively
Dayton, Ohio
Hi Mark,
Sorry it took so long to answer you back, th Allexpert sight has been fill all week. Here goes the answer to your question.
The bike does not idle the same at anytime its run. If you adjust it to idle, then go out for a ride, when you come up to a stop the bike ether stalls or idles very high. If you adjust the idle and ride some more, the same thing happens. It won't idle the sameno matter what you do. There is also a bad flat spot in the power band, about half 1/2 to 2/3 throttle.
The bike has had the carbs pulled and completely gone through, floats set and carbs balanced. Plugs were checked, all seem to have good color.
One more thing my mechanic wanted to mension. The voltage regulator went out on the previous owner, about a year and a half ago. Just before I got the bike, the regulator wet out again and was replace. Both times the bike seemed to run better after the replacement. Don't know if these are related, but I thought I'd let you know.
One final thing, the valves havn't been adjusted because we didn't have the specs for a variable valve model. I got these the other night from a web sight called Bandit Alley.
P.S. Is there a web address I can use to write to you without having to go through Allexperts?
Thanks for the help,
Kent
AnswerKent,
The carbs are not working properly and it's not from the electrics. Check for an intake air leak, pinched or collapsed vacuum hose, and then check synchronization.
How well the carbs were cleaned is something to consider, too. I cannot express how important it is to thoroughly clean carbs. Every pinhole has a crital function and must be unobstructed.
Valve clearances and cylinder compression MUST be within service limits before the carburetors will work properly.
Perform a altenator output test and check individual charging system components to verify the integrity of the charging system. The battery must be fully charged and in good condition prior to testing.
Visit the following website and use the "troubleshooting chart" if necessary to check the charging system: "www.electrexusa.com" These are very high quality electrical replacement parts. Puy this brand if you find any defective electrical parts. Much better than OEM parts.
Verify the charging system is working properly. Check cylinder compression and valve clearances. Check carbs again.
The reason I request your email in my instructions is for our convenience.
mshively1@woh.rr.com
Mark
