Loud Tapping Noise On Cold Start

[j4rdemotox]

When I start my 400ex up I get a loud sharp fast tapping noise :confused: . The more the engine warms up the tapping noise slows down & starts going away. (The Tapping noise does not last long) I am going to check my valves this weekend, but want to see if any one as any other ideas.

Once the quad warms up it is fine. Runs strong!

I just purchase this quad & had it shipped to me from Missouri.
It is a 2002 400ex. No real upgrades. Slip on Big Gun. That's it

[Silverfox@C&DRacing]

If the valves are fine, you might want to switch to a different oil, sounds like the oil is too thick for winter.

[zephead400ex]

Originally posted by Silverfox@C&DRacing
If the valves are fine, you might want to switch to a different oil, sounds like the oil is too thick for winter.

j4rdemotox - not stealing your thread

But will running too thick of oil (15w50) during the winter months, will it hurt your engine?

thanks

[Colby@C&DRacing]

The thicker oil like you listed can add more wear to the motor on startup in the cold winter months. after the motor warms up it is fine. You might look at switching to a 10w40 for the winter, I like full synthetics they are much thinner at cold temp and flow better.

[j4rdemotox]

Thanks
I purchase new oil. I have not change it yet. I am going to do that @ the same time I check my valves.

[remlapr]

Pretty sure what you're talking about is called piston slap. If I remember right it's that the cylinder heats up and expands fast them then piston causing the piston to be loose until it heats up. Mine does it after about 30-60 seconds but it only last for about 30 seconds then goes away.

[j4rdemotox]

I just recieved my bick from MO. I live in Cal. I normally run 10-40 in all my bikes. I thought since it came from MO. it would have 10-40.

[j4rdemotox]

I do not think it is a piston slap. The noise pich. is to high. I does sound more like my valves. I will keep that in mind. I will not rule that out.

[300exOH]

You could use a screwdriver or a stick and listen while the engine is running near the valves at the top of the head to be sure. Move around the engine and see where the sound is coming from.

[zephead400ex]

Originally posted by Colby@C&DRacing
The thicker oil like you listed can add more wear to the motor on startup in the cold winter months. after the motor warms up it is fine. You might look at switching to a 10w40 for the winter, I like full synthetics they are much thinner at cold temp and flow better.

Thanks Colby. Any recommended brand? I usually run Mobil 1 red cap.

[j4rdemotox]

I juste want to say thanks. You guys are very helpful & I really appreciate it.

once you run the mobile 1 red cap 15w-50 stuff you can never go back right? since its synthetic?? i just put it in mine & I love it!

[skemp]

Basically, what is happening is that the oil is so thick at cold temperatures that it takes a long time to be pumped up to the cam/valves when you start it. The ticking or tapping noise that you hear is metal to metal contact in the valvetrain. This is also a common problem in cars and trucks. Used to be that when you heard that, it was getting too cold and you had to switch to a lower viscosity oil. My quad is usually kept in a warm place during the winter months, but I still switch to Amsoil 10w40. There is a lot less heat strain on your motor in the winter so the lower viscosity won't yeild any bad effects.

[zephead400ex]

Originally posted by Jumbo747
once you run the mobile 1 red cap 15w-50 stuff you can never go back right? since its synthetic?? i just put it in mine & I love it!

I would still use a synthetic oil, but not such a heavy weight. But I need to know a good weight to run.

thanks

[j4rdemotox]

OK, I took a look @ my valves & they did not need adjusting. I change my oil to 10/40 semi synthetic. I start my bike & the tap noise was not as bad. So, I left it alone. Today I went to start my bike & it does not want to stay running barley wants to start. I have to turn on the choke to get it started. Once it starts it runs ruff & backfires a little then dies. If I get it running & open the choke a little bit it dies. It has ben running good. I have ridden it once since I gotten it & it ran good. I got it out of MO (1035 ABL) I live in Clovis, Ca (365' ABL) Temp here is 40-45 degrees. I fouled a plug.

Any ideas

[400exBro]

i run 5w-50 all year round, haven't had any problems with it so far. It is kendall full synthetic motorcycle oil, expensive but good stuff.

[WhiteBros400ex]

i have the same problem i adjusted my valves and it did not work it still had the tap so its at the shop now seeign what it is i never though about oil but when its get back ill let u know what they told me about it.

[j4rdemotox]

Please let me know.

I have change my oil 10-40 & looked @ my valves. ( They did not need adjusting). Still have the tapping noise. Sounds like it is from my exhaust valves. I may do a compression test.

Only when it is cold I get the tapping noise. Once it starts warming up the noise slowly goes away?????? :confused:

[j4rdemotox]

What I did not say is that it only tap on idle, if I rev the motor up a little the tap goes away. Once the motor warms up it goes away.

[CJ400EX]

Maybe the decomressor system. ????

[CJ400EX]

i have the same problem i adjusted my valves and it did not work it still had the tap so its at the shop now seeign what it is i never though about oil but when its get back ill let u know what they told me about it.

HAVE YOU HEARD ANYTHING YET?