Replaced top cylinder head, Now it wont Crank

[Dirty Minnie]

Okay I replaced the very top head cause the old one had stripped oil bolt holes. I just pulled the old top cylinder head off and put the new one on. Now it wont start, I have spark from plugs but feels like low compression when I kick it over. It also admits a big whooshing noise from the carbs and the hose running from the top. I'm a Dirt bag mechanic and I have no idea what could be going on need some assistants please.

 

[ippytattoo]

First off the rocker box cover and the head should have been changed as a matched set along with a new head gasket. Now for the standard questions: 1. Was it running before you changed the rocker box cover? 2. Have you done a compression test with a proper tester and if so what were the compression numbers. 3. Have run through the normal maintenance items (cam chain tension, valves adjustment and timing)>

 

[Dirty Minnie]

A mechanic told me to just change the very top rocker head. Was not aware that it needed to be a matching set. Yes it was running perfectly fine minus the oil leak which was the cause for the switch, I have not compression tested it don't exactly have that in the garage, and timing is exactly where I had it marked I never touched the cam or the valves

 

[ippytattoo]

The adjusters for the valve lash are in the rocker arms which are in the rocker box cover. I would start there. The motor must have been removed from the bike to change the rocker box cover so if you have points I would also check to make sure the points wires are going to the correct coil. A simple check would be to swap the spark plug leads from left to right and vice versa.

 

[Dirty Minnie]

Alright ill pull it out again tomorrow. Then ill check back. How do I exactly properly adust the valve lashes

 

[Soliddrummer]

Use the search function in the forums. Valve adjustment has been discusses to exhaustion.step by step, videos, the whole bit.

 

[ippytattoo]

To adjust the valves you do not need to pull the motor, it is a routine maintenance item. Here is a video of how to adjust the valves. Good luck.

 

[XSLeo]

You can find the valve adjustment "How To" in your repair manual.
Leo

 

[5twins]

Dirt bag mechanic indeed, lol. What's next on the "to do" list, brain surgery? How hard can it be, right? Drill a few holes in your skull and have at it.

 

[cra-z1]

Dirt bag mechanic indeed, lol. What's next on the "to do" list, brain surgery? How hard can it be, right? Drill a few holes in your skull and have at it.

5twins tells it like it is. Sounds like he needs a manual

and Leo drops a subtle hint

 

[Dirty Minnie]

When I said pull it out I meant her I had to pull her back out as in the bike lol but I opened up the covers checked the valves. They were all good, put the covers back on and compression was back and she fired right up I guess it was a fluke.

I think I've done a all right job with my bike for someone who wanted a bike his way for what I wanted to pay which wasn't alot haha, but thanks for all the help you guys

 

[Dirty Minnie]

5twins sometimes you do what you got to do even if it costs you all of your motor functions haha

 

[Dirty Minnie]

5twins sometimes you do what you got to do even if it costs you all of your motor functions haha

 

[jayel]

would have been easier to heli-coil the old valve covers stripped oil holes

 

[XSLeo]

I was just going to suggest this, fix the threads in the rocker box that was on the engine.
The mismatched rocker box may work, but it may seep or leak oil.
With the right box fixed and you do have problems you can swap it back.
Leo

 

[cra-z1]

I would use Timeserts