[heavywt82]

I bought a 2004 Marauder a couple of weeks ago from a used bike dealer with 1800 miles on it. Almost ever since I hear a distinct knock that is definitely coming from the motor. The only time the noise is not present is when the bike is coasting or idling, and it gets worse with the increase of load on the bike (hard throttle or with a passenger).

Now, I know quite a lot about CAR engines, but am a little lost when it comes to bikes, especially v-twins, as I have never owned one. Could this be the same rod knock as with a car motor?

Any suggestions as to what to do?

 

[krisdo]

This problem is well documented. The factory fuel map is set very lean so that the bike will pass federal emissions requirements. I have been told that this is harmless and will not hole the pistons by my dealer, the Suzuki factory rep, and the Kawasaki factory rep.

Problem is, I don't believe them. It goes against everything I ever heard about excessive lean conditions, even if the pinging is mild.

I have talked to tech guys from NGK and Dynojet.

NGK:
"...you would need to use a cooler spark plug in order to eliminate pre-ignition. The cooler spark plug for your application is the DPR7EA-9 stock number 5129. "

Dynojet:
"...as far as I know no one has specifically complained of this problem. We are aware that these bikes are quite lean in the low to midrange. By adding fuel to the lean areas it will increase throttle response and overall drivability. This may also get rid of the pinging. We do have a map for a stock bike which is map 318-001. This will give you the optimal fuel curve for your setup." (That would be for a Power Commander)

I'll probably try the cooler plugs first, but I'll probably get a Power Commander anyway- I like the idea of being able to optimize the fuel mixture with just a laptop computer...

Hope this helps.

 

[heavywt82]

Ping vs. Knock

Thanks for the quick reply, krisdo. I noticed your post with pics of your bike… mine is same color, but with 2400 miles on it and no scoop.

The sound I was referring to is not the ping you spoke of, though I also have the ping. I get it when throttling hard from under 3000 rpm, and occasionally when throttling hard at higher revs.

The sound that worries me is the knock I hear. I really think it’s a rod, but never having owned a v-twin I can’t say so with complete certainty. The sound is always present and its rate increases and decreases with rpm.

I bought the bike from a used dealer in Daytona with 1800 miles on it, and was told warranty was good until 2006. I didn’t think to ask for service paperwork and original purchase date until I went to a Suzuki dealer to transfer the warranty into my name. Dealer said I must have service proof (600 mile I guess ‘cause it’s the only one due) and that I needed original warranty info. Used dealer has been no help in getting in contact with original owner. I called Suzuki Corporate and was told the dealer was full of ****, and that all I needed was to sign my name on the dotted line. I get the feeling though that even if I get the warranty in my name, if the bike throws a rod, the dealer will want proof that 600 mile service was done before making $1000’s of repairs for free.

I think I may be up the proverbial creek without a paddal.

 

[krisdo]

Update: I put the cooler plugs (NGK DPR7EA-9) in yesterday and took a one hour ride. The ambient temperature was about 60 degrees. The pinging was still present, but much quieter, and only in a much narrower rev range.

I think I'm on to something here... I'm still getting the Power Commander, though. My dealer has put them on several Yamaha Warriors that apparently have the same problem, and it was solved.

BTW, I learned something about spark plugs. That "7" in the middle of DPR7EA-9 is the heat range indicator. "2" is very hot, "10" is very cool. The stock plugs for the 1600 are DPR6EA-9's, so I went one step cooler.

 

[krisdo]

Update 2: I just got back from a two hour ride. (I had the day off today; it's sunny and 64 degrees here in N.C.)

Anyway, I got the bike warmed up and rode it fairly hard during that two hours on varying roads. With the cooler plugs, the pinging is almost gone. I have to romp it pretty hard between 2-3,000 rpm to get it to ping at all, now. At cruising speed, say, 65mph, I can't hear a thing. Now the engine seems to make the normal, mechanical noises made by every bike I've ever had. I'm happy. I think those stock pipes sound pretty good- kind of a musclecar burble. I like the sound a lot better than my straight pipe equipped V-Star 1100. So do my neighbors.

Excuse me. I'm going to get a beer, sit out on the porch, and listen to the bike cooling off. A favorite ritual of mine...

 

[pem]

vz 1600 marauder

I had the same noise then started hearing a hissing noise. the shop said the hydrolics lifters were sticking so they flushed the system with auto transmision fluid, seemed ok but after puting 100 miles on it the hissing came back.. so I got a conpression testor and found 90 psi on the front and `120 on the back I think some valves got bent .. havent heard the verdict yet.. the warenty beter cover it.. love the bike ,,..

 

[pem]

got my bike back but nothing resolved. the dealer and MFG SAID THAT THE COMPRESSION NORMAL is 80-90 psi. that equates to only 6:1 compression ??? I'm not sure what to think. has any one else checked there compression ????

 

[md2lgyk]

The compression ratio on that motor is 9.0:1.

 

[pem]

I'must curious if anyone else has checked there compression?? The formula that I use is PSI devided by the atmospheric PSI this will give you the compression ratio or close. THe spec is 9:1 but when testing you only get 80 - 90 psi and atmospheric presure @14.25 psi that is only 6.3:1 9:1 should equate to @128 psi. IT's the 30 psi front to back diff that bothers me.

 

[axel_2078]

I have an '03 Marauder 800 and I haven't noticed the pinging you were referring to, but once I get to 70 mph, the engine starts to whine noisily and grows stronger with increased speed. At 80 mph, it's very loud and the bike shakes a lot. Is this normal?

 

[St0nkingByte]

The 800 Marauders run at high RPMs at highway speeds due to their gear ratio. Some people correct this by replacing the 15 tooth front sprocket with a 16 or 17 tooth sprocket (I think I've got the #'s of teeth right) or by converting to a belt drive which comes with a higher gear ratio. This change 'raises' all the gears so they are all a little higher. I've heard it can make the bike a little slower from a stop but generally makes highway cruising much nicer. I have a '97 Marauder myself and I run at 60-70mph daily and it doesn't really bother me but sometimes I do get that 'where is six gear' feeling.

That said excessive vibration and noise might be an indication of another problem. It all depends on what your tolerances are. My Marauder is also my first bike so its my definition of normal

 

[dirtyfingers]

The 1400 and 1600 Suzuki V-twins use an electronic decompressor on the front cylinder. A decompressor holds the exhaust valve open to ease the load on the starter. So..... a compression test will always show a low reading on the front cylinder, unless the decompressor is disabled. As for the knocking, has anyone tried a higher octane fuel? or an octane booster?

 

[SonsVS800]

Cam overlap affects pressure...

The cam overlap of an engine and valve adjustment, are just a couple of factors that affect the PSI reading on a compression test. For example a high compression engine or the short overlap of a street cam will in crease PSI reading. Loiw compression and big overlap (radical cams) will lower PSI. A high compression engine with a radical cam can read low like an engine eith a problem...

 

[stuvan2]

I too have this knock around 2000-3000 rpm. Was told by the dealer that this is normal. Am getting a second opinion. What if anything have you been able to determine?