do not ever sand ur head or block surfaces ever.
| MudmotorTalk.com http://mudmotortalk.com/mmt_v2/ |
|
| Added heads finally and lost power http://mudmotortalk.com/mmt_v2/viewtopic.php?f=3&t=33244 |
Page 1 of 1 |
| Author: | SCmudder7071 [ Sun Oct 14, 2012 1:08 pm ] |
| Post subject: | Added heads finally and lost power |
I put my IM heads on finally and am having some problems now. My throttle response is slower but it would still turn 4200 oow but I have no power. Put it in today and it wouldn't turn over 2400 rpms. Valve lash was set by Cody's way and then I tried it per Briggs by going off TDC. What is yalls opinion? Could I be pulling in air through a damaged gasket? Would it cause that? Any help is appreciated |
|
| Author: | cb5331 [ Sun Oct 14, 2012 1:12 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Check the compression. You set the valves Cody's way, and then Briggs way. How much difference was there in the lash? There really shouldn't be any. From the info you gave, I would be guessing you screwed up the lash. Hopefully you didn't damage the cam. |
|
| Author: | Pooh Bear [ Sun Oct 14, 2012 1:16 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Did you set the valves on the compression stroke? |
|
| Author: | swamprat26 [ Sun Oct 14, 2012 1:18 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Compression test will tell of a bad head gasket and you prob would hear it Sent from my iPhone using Tapatalk |
|
| Author: | SCmudder7071 [ Sun Oct 14, 2012 1:20 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Whats the best way to check.compression? Asking because I dont have a ton of fancy tools. I set it per Codys way and when the throttle was lagging I double checked it per Briggs method. I ran the boat for at most 20 yards when I realized something wasn't right. If the cam is damaged it'll be okay because I'll be replacing it soon |
|
| Author: | cb5331 [ Sun Oct 14, 2012 1:24 pm ] |
| Post subject: | Re: Added heads finally and lost power |
When you double checked the lash, was it spot on or did you have to change it again? You can borrow a compression tester from your local auto parts store. Pull the spark plug, insert the fitting on the tester into the spark plug hold, hold the throttle WOT, and turn the starter until the dial quits going up. Just a few revolutions should suffice. Make sure you remove the plug and/or the plug wire on the other side before testing so the motor doesn't fire up on one cylinder. |
|
| Author: | SCmudder7071 [ Sun Oct 14, 2012 1:29 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Lash was spot on. No adjustment needed. And cool. I will do that asap. What does it sound like to you CB? |
|
| Author: | swamprat26 [ Sun Oct 14, 2012 1:30 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Compression test will also tell you if valves are holding. Did it backfire any? Sent from my iPhone using Tapatalk |
|
| Author: | SCmudder7071 [ Sun Oct 14, 2012 1:32 pm ] |
| Post subject: | Re: Added heads finally and lost power |
No backfire at all. It really has me stumped on what the hell is going on. |
|
| Author: | WestEndAngler [ Sun Oct 14, 2012 2:02 pm ] |
| Post subject: | Re: Added heads finally and lost power |
I bet the IM heads are the problem get Cody to fix 'em |
|
| Author: | cb5331 [ Sun Oct 14, 2012 2:03 pm ] |
| Post subject: | Re: Added heads finally and lost power |
If lash was spot on, im relatively confident that part is okay. I'd proceed with a compression check and go from there. If those numbers are bad, you'll need to do a leak down test. |
|
| Author: | h2ofowlhunter [ Sun Oct 14, 2012 2:25 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Are you firing on both cylinders? |
|
| Author: | SCmudder7071 [ Sun Oct 14, 2012 2:47 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Yes it is firing on both cylinders. Its idling great. Idle is set at 1100. The power just isnt there. |
|
| Author: | Team Camo [ Sun Oct 14, 2012 3:23 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Had one a while back firing on both, but wouldn't run on both. Pull plug wire to see if it'll still run on one cylinder. My case ended up being blown gasket between cylinder and push rods. Couldn't hear it while running, but had no power. |
|
| Author: | SCmudder7071 [ Mon Oct 15, 2012 12:44 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Same problem on mine Camo. Ran compression test on it this morning and it failed. Tore it down and found that a head gasket was damaged. |
|
| Author: | swamprat26 [ Mon Oct 15, 2012 12:52 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Head gasket will do it Sent from my iPhone using Tapatalk |
|
| Author: | dadazzsaleen [ Mon Oct 15, 2012 1:53 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Just came across this. Glad you go it figured out. Once you have it dialed in, let me know how it performs |
|
| Author: | tchauvin [ Mon Oct 15, 2012 1:56 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Think of it this way, 2400rpm with one blown gasket, so now you may get 4800 |
|
| Author: | Will [ Mon Oct 15, 2012 5:32 pm ] |
| Post subject: | Re: Added heads finally and lost power |
When you go for round two, You need to take some sand paper and rough up the face of the cylinder a little, this will help the gasket "grab" the face. If you will notice the factory surface is very smooth and almost mirror like, not good when you want a gasket to seal. |
|
| Author: | SCmudder7071 [ Mon Oct 15, 2012 5:37 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Actually did that Will. Cleaned all the old gasket off and scuffed the surface. My next question tho is do y'all put a sealant along with the gasket. I didnt use a sealant because my step-dad said it wasn't necessary. Im asking because I dont want to pull the dang thing apart again for another simple fix. |
|
| Author: | Will [ Mon Oct 15, 2012 5:49 pm ] |
| Post subject: | Re: Added heads finally and lost power |
No sealant, in fact clean it with alcohol before you put on the new gasket. |
|
| Author: | cb5331 [ Mon Oct 15, 2012 6:08 pm ] |
| Post subject: | Re: Added heads finally and lost power |
I use copper spray on the head gaskets. Don't know if that is a good idea or not, but I haven't had any issues and have done it this way on all the motors I've put together. |
|
| Author: | richard nagon [ Mon Oct 15, 2012 7:52 pm ] |
| Post subject: | Re: Added heads finally and lost power |
do not ever sand ur head or block surfaces ever.
|
|
| Author: | SCmudder7071 [ Mon Oct 15, 2012 8:03 pm ] |
| Post subject: | Re: Added heads finally and lost power |
Why would that be Richard? Just curios. It wasnt a heavy sanding. Just a slight scuff. We do that on just about every surface that has a gasket on it on the equipment around the farm and vehicles. |
|
| Author: | richard nagon [ Mon Oct 15, 2012 8:38 pm ] |
| Post subject: | Re: Added heads finally and lost power |
sc. a alum head and block most call for a 30 to 50 ra finish. a finish that is hard to see with a eye. for a proper seal. by sanding the surfaces u could be putting in as high if not higher 100 ra. not good what ur are doing is intoducing a path way for gases to pass thru. u don't want a head gasket. as Will says that bites. during a heet cycle a head gasket moves causing what is called scuffing. which is normal. a high ra or sanded rough surface over time will cause a delaminating of the head gasket seal. causing a head gasket leak. i always clean the surfaces with a plastic scraper and howes lubricant to remove gasket material. never use a die grinder with a rolox pad a metal scraper or razor blade. |
|
| Author: | SCmudder7071 [ Mon Oct 15, 2012 8:50 pm ] |
| Post subject: | Re: Added heads finally and lost power |
You do make sense. Just for clarification so I don't look like a total fool I did not use a die grinder or any highly abrasive material. I did use a 600 grit sandpaper. Thanks for the info Richard. It is nice having a forum dedicated to idiots like us who love running a lawnmower motor and constantly pushing them to the limits. Its also nice that there are some of y'all that are extremely knowledgeable about these motors |
|
| Author: | cb5331 [ Mon Oct 15, 2012 8:52 pm ] |
| Post subject: | Re: Added heads finally and lost power |
| Author: | richard nagon [ Mon Oct 15, 2012 9:08 pm ] |
| Post subject: | Re: Added heads finally and lost power |
sc. i might of went over the top.  but be careful dressing up a head or block surface. deep scratches cause problems down the road.
|
|
| Author: | Will [ Tue Oct 16, 2012 4:45 am ] |
| Post subject: | Re: Added heads finally and lost power |
rn. I understand why you say not to scuff the surface, it makes since no doubt but that's the way I've been told on many different motors. What about the case gasket, what's the best way to "try" to fix that leaky bastard? |
|
| Author: | sftull [ Tue Oct 16, 2012 5:58 am ] |
| Post subject: | Re: Added heads finally and lost power |
| Author: | MaXXis85 [ Tue Oct 16, 2012 7:18 am ] |
| Post subject: | Re: Added heads finally and lost power |
| Author: | Will [ Tue Oct 16, 2012 7:21 am ] |
| Post subject: | Re: Added heads finally and lost power |
I've got mine pulled right now bout to put in a new clutch, thought I might just dip the bottom half of the motor in a tub of silicone...
|
|
| Author: | SCmudder7071 [ Wed Oct 17, 2012 9:36 am ] |
| Post subject: | Re: Added heads finally and lost power |
Thanks for the help fellas. I put the motor back together this morning and the power is there. Now its time to eat CDMs spank new PD rig this weekend
|
|
| Page 1 of 1 | All times are UTC - 6 hours |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|