Please Help...can't get trike to start after installing new top end

[patblkwell]

Hey guys, I picked up a 1985 Yamaha 225dr that would start via the pull-starter (electric start wasn't working) but had low compression and would smoke some. I just recently installed a new top end kit with (stock size not bored over) and cannot get it to start now. The motor is getting spark, gas and air so I am not sure what the problem is. It's like it's not even wanting to try and start for some reason. I did set the cam chain and guide to how it's supposed to be per the manual fyi. I'm sure it would be easier to diagnose if the electric start was working vs. pull starting it, but any other ideas on what it could be? thanks

[patblkwell]

Compression is good. Cleaned and re-lapped the valves. The cam timing was set as shown here before replacing the top end which is off 180° according to the manual. Second pic is from the manual.

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[atc007]

Did you check the valves for seating before assembly? Fill the ports full of ether and see if any seeps through? You may have a slightly bent valve. However, you say compression is good. The pull starter should try and tear out of your hand on a healthy fresh engine.

[fabiodriven]

That engine will pull the pull cord right out of your hand. My buddy broke his finger pulling my DR over. Always use the compression release! I wouldn't worry too much about the electric start. Mine started first pull every time, warm or cold, but for whatever reason it wouldn't always start with the electric start.

[patblkwell]

Whats odd is that it isn't super hard to pull start like you all are saying. It doesn't seem to matter if I flip the compression release or not and sometimes when I try to flip the compression release it won't stay in place?

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[patblkwell]

It's not easy but definitely not trying to rip my arm off...

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[patblkwell]

Yes I am aware that the cam cannot be 180º out...when I was removing the old top end that's how it was set when the T mark was viewable through the eye hole in the crankcase. I put it back to how it should be according to the manual. I am definitely a novice when it comes to working on these which is why I am on here for assistance from some of you engine gurus

As far as the compression release switch, what I mean is sometimes when you go to flip it on, it will not stay engaged. I know that once you pull start the trike it releases on its own. I was referring to prior to pull starting.

[fabiodriven]

Yeah as Damon said, the compression release will not always stay popped if the engine isn't in the right position so no worries there. If it's not trying to yank the pull handle out of your hand then something is wrong. I tend to agree with what Damon is saying about some of the possible issues you might have on a mechanical level. Please take Damon's stern tone with a grain of salt, he's here to help. Lol!

[atc007]

At this point, if you don't have a good compression tester. If you have another person. Plug the plug hole with your finger. It should burn it real good if there is enough compression. You can also try pull starting it behind a truck or another vehicle. If she don't start then. You are going back in for sure. Have you shot ether in the plug hole/back of carb and it does not sputter?

[patblkwell]

I haven't tried starting fluid yet, but will. 10-4 about the cam.

[fabiodriven]

He was suggesting ether to see if the valves were seated, not for starting. (Never mind. It was suggested for starting as well. I'd steer clear. You said it's getting fuel.)

I respectfully would disagree with Bill about pop starting it or towing it behind a vehicle. In my opinion, if you have to pop start it there is definitely something wrong. Not only that, but if something is out of place in there and decides to come loose while you're dragging it behind a vehicle, there is going to be very little forgiveness. You could easily put a valve right through the piston.

Forget about trying to fire with starting fluid and pop starts, you're way past that stuff. It sounds to me like your next step should be a compression test.

[El Camexican]

If I can expand on Dude's comments, you need to remove your sparkplug and rotate the engine forward (counter clockwise when facing the left side) until you get your fly wheel "T" mark lined up with the marker on the case cover and then look at where the mark on the cam sprocket is in relation to the mark on the cylinder head. It should point up, a 180 degrees to what your photo shows.

I hope the marks line up, because if you are off by just one tooth there's a good chance you've bent a valve. If the marks do line up start looking at valve adjustments and take a compression test.

A few words of caution for future endeavors; Always rotate a 4 stroke in the same direction as it runs, use EXTREME caution rotating an engine until you're certain your timing marks are correct, never over tighten a cam chain and when in doubt back your valve lash off when checking timing. Great way to avoid bending them if you do end up a tooth off.

Oh, and always make sure you have gas in the carb before tearing a perfectly good motor apart

[patblkwell]

Thanks for all the tips and suggestions guys....I will definitely keep you all updated on this. I knew it was a project when I got it haha.

[patblkwell]

I will get a pic of the cam, T mark on flywheel, etc. tonight to show you.

[patblkwell]

This is how I set the cam timing

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