1992 quadrunner 300 4x4 engine not spinning free

[97kingquad]

I have been rebuilding some ATVs in my spare time and teaching myself along with the help from the internet how an engine works and getting bikes running again is quite enjoyable. I even built an arctic cat 300 4x4 from two parts bikes the had seized motors and missing parts. It was pretty enjoyable. 

 

So I am now working on a sazuki quadrunner 300 1992 which had a whole list of issues when I got it. I have fixed almost everything I need to in order to get this bike running. But something is going on inside the head or crankcase. 

I had to replace the timing chain because it was very stretched due to the previous owner.

 

What the issue was, the timing chain was off the sprocket inside the engine due to it being stretched it slipped off. So the previous owner rebuilt the top end thinking it would fix it which it may have temporarily, but when doing so they welded an extra inch onto the tensioner to hold the chain tight. Which as you can imagine caused a dozen other issues.

So that stretched the chain to the point where I could remove the cam with the tensioner in.

It beat the sliders all to hell. Destroyed the cylinder housing and obviously ruined the tensioner. 

I didn't realise all of this until after I rebuilt the engine.  I noticed wear where the timing chain runs through the cylinder. I found the cam had no retaining chair, or clip whatever you want to call it so the cam was beat to sh** also. It had almost an inch of play side to side.

So I pulled the head off of my parts bike and fixed all of it. Then put it together and went to pull it over and found it was not on the sprocket (this is when I realised that all that damage and the welded tensioner was because the timing chain had been off the sprocket) 

So I pulled the stator cover off and pulled the flywheel (which I should add to get at the stator cover I have to remove the rear tire and a arm as well as remove the bolt through the front of the engine. And the exhaust system has to be removed to pull the cylinder as the exhaust guard is bolted to the side of the timing chain tensioner. Stupid setup. Glad the king quad doesn't have that. 

So I got everything apart and the flywheel off. New timing chain (nice and tight now) put the head back together and flywheel but it is quite hard to turn the engine over. I can but with difficulty. When the valve cover was off it seemed to spin much more freely. Before I tear everything back apart and start again any ideas on what it is? 

[Gwbarm]

My first thought is the head from the parts bike might be not be an exact fit, especially after you said it seemed tighter after installing the valve cover, or are the valve covers different from head to head, might check that. I would take the valve cover back off and see if they are any shiny areas where it is rubbing.  That engine was a mess you have done an amazing amount of work to get it right. Very impressed with your dedication!

[97kingquad]

Thanks gw, I took the valve cover back off and it spun normally again I can't find any difference between the two besides some wear on the head from the carnage before. But I just put the old head back on and I can turn the engine over now 

[Gwbarm]

Interesting, since you have the old head back on , try running it and see how it goes, if problematic you could try rebuilding it, or you could use the other head and double gasket the valve cover and see if it gives you enough clearance, but there might be discrepencies other places that would cause problems.

[97kingquad]

5 hours ago, Gwbarm said:

Interesting, since you have the old head back on , try running it and see how it goes, if problematic you could try rebuilding it, or you could use the other head and double gasket the valve cover and see if it gives you enough clearance, but there might be discrepencies other places that would cause problems.

I can not find any gasket kits for the valve cover. I have bought 3 rebuild kits for different bikes and none come with a valve cover gasket so I can't double gasket. I did think that maybe there is supposed to be some room between the two mating surfaces so I ok it some rtv and let it sit finger tight overnight so I'll tighten it down and see how it is. 

[Gwbarm]

Good that will work

[97kingquad]

On 12/2/2023 at 2:11 AM, Gwbarm said:

Interesting, since you have the old head back on , try running it and see how it goes, if problematic you could try rebuilding it, or you could use the other head and double gasket the valve cover and see if it gives you enough clearance, but there might be discrepencies other places that would cause problems.

So I have come to admit my wrong and in the event anyone else is suffering a similar issue. 

I put the starter gear on backwards lol I switched it around and now everything is working as it should. Putting the stator cover back on now and we will see if she will fire up then 

[Gwbarm]

Good you caught that , glad to hear everything is working. We have all been there, look at it this way you wont make that mistake again, its part of the learning process. Good luck, and keep us informed. 

[97kingquad]

Lol well I went over the gears many times now so I have the installation memorized at this point. But I will post some pics of the process after I get it back together 

[Gwbarm]

Love to see them, i really like restoration projects, take something abandoned and make it good again.

[97kingquad]

7 minutes ago, Gwbarm said:

Love to see them, i really like restoration projects, take something abandoned and make it good again.

You should check out my arctic cat 300 rebuild thread 

[Gwbarm]

I definately will do that. Thanks!

[Gwbarm]

I did see your revival of the Arctic Cat. Very nice. I have not had the oportunity to own an Arctic Cat, but i understand the 2 suzukis i have share the same engine as the Cat. Im in the south and while there are a few around, mostly the 4 Js, Honda, Yamaha, Kawasaki, and Suzuki.