chrispy56 Posted February 15, 2014 Author Report Share Posted February 15, 2014 I'm beginning to think the oil that is spitting out of my exhaust contains coolant. Lot of residue on front side of motor too. Could a leaky head gasket be the cause of a problem like this? Quote Link to comment Share on other sites More sharing options...
camatv Posted February 15, 2014 Report Share Posted February 15, 2014 leak test your coolant system. shake the flywheel if it rattles magnets are coming apart. also look across the top if its warped may have been taken off with a 3 jaw.. thats a dead giveaway. check ground drop on the stator plate to the main ground on the harness also. Quote Link to comment Share on other sites More sharing options...
mcgyver Posted February 15, 2014 Report Share Posted February 15, 2014 I'm having the same exact problem but I'm waiting till it's warmer to diagnos any further. Let me know if you figure anything out. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted February 15, 2014 Report Share Posted February 15, 2014 I have had a pressure test go well but o rings still leak when hot , usually protocall for me is pressure test, compression test, check pick up, plug cap ohm reading(never good), cable play carb sync , before I even kick someone elses bike. I had a bad experiance a few years back , a well known builder built this kids motor but he needed it tuned didnt do my usual machanical testing and I blew a hole in piston within 20ft from my driveway , turned out to be not enouph cas sealant behind crank just plain out missed 3 inches. Im sure piston was already going b4 it got to me Quote Link to comment Share on other sites More sharing options...
chrispy56 Posted February 18, 2014 Author Report Share Posted February 18, 2014 Should have done it sooner...checked compression-60psi in each cylinder. Not sure how it could run with compression like that. I will pull the head and inspect. Things to look for? The 4mil with stock cylinders from HJR should use 795 pistons correct? I will tear it down this week, hopefully I find my problem. Quote Link to comment Share on other sites More sharing options...
J-Madd Posted February 18, 2014 Report Share Posted February 18, 2014 Sounds like you're running 795 pistons on 110 mm rods. Quote Link to comment Share on other sites More sharing options...
chrispy56 Posted February 18, 2014 Author Report Share Posted February 18, 2014 I was afraid of that...I bought all the parts from HJR as a kit, and assumed they were correct. But still not sure that's it, I will find out during tear down...Will the rods be marked with their size on them? I didn't notice during assembly. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted February 18, 2014 Report Share Posted February 18, 2014 Yes should say ck158 unless you got wanged Quote Link to comment Share on other sites More sharing options...
chrispy56 Posted February 19, 2014 Author Report Share Posted February 19, 2014 the rods say G-115 on them...I assume this means 115mm. Quote Link to comment Share on other sites More sharing options...
chrispy56 Posted February 20, 2014 Author Report Share Posted February 20, 2014 Squish test shows .06"...what am I aiming for? The domes were cut for pump gas. Quote Link to comment Share on other sites More sharing options...
J-Madd Posted February 20, 2014 Report Share Posted February 20, 2014 That's maybe a tad high on the squish but doesn't explain your low PSI. Did you kick it over at WOT until the gauge stopped moving? What was the ring end gap? Was it bored at a machine shop that had the pistons on hand to measure? Was it honed? Quote Link to comment Share on other sites More sharing options...
chrispy56 Posted February 20, 2014 Author Report Share Posted February 20, 2014 Yes. I kicked until the the dial quit moving and then some. End gap was to spec from what I remember...I will double check tomorrow. Bored and honed and ported by HJR and he had all parts in hand. I appreciate all the suggestions and please keep them coming as I am running out of ideas. Very frustrating. Quote Link to comment Share on other sites More sharing options...
chrispy56 Posted February 20, 2014 Author Report Share Posted February 20, 2014 I will also try to borrow another compression gauge and see if I get different readings Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted February 20, 2014 Report Share Posted February 20, 2014 Okay I just read this is a hjr motor. I had an hjr motor. Now I don't. When I got everything together my squish was a little loose. I called Kevin he said all good. I asked about jetting. He gave me a point to start. Well I got the bike running. Not like a 4 mil tho. So I call Kevin, he would just say play with it your close. And that was it. So after a season of "playing with it" a unrelated issue took out my motor. Went to a local builder, and he pointed out that my domes were wrong, and the porting was a little excessive for what I was doing and the port I was told it was. So my dealing with hjr left a sour taste in my mouth and a unhappy costumer. Now I know I'm going to get pm's that I'm an idiot, don't know what I'm talking about, but this was my personal dealing with hjr. I also know of another member that had exactly the same issues as me. Quote Link to comment Share on other sites More sharing options...
chrispy56 Posted February 20, 2014 Author Report Share Posted February 20, 2014 Okay I just read this is a hjr motor. I had an hjr motor. Now I don't. When I got everything together my squish was a little loose. I called Kevin he said all good. I asked about jetting. He gave me a point to start. Well I got the bike running. Not like a 4 mil tho. So I call Kevin, he would just say play with it your close. And that was it. So after a season of "playing with it" a unrelated issue took out my motor. Went to a local builder, and he pointed out that my domes were wrong, and the porting was a little excessive for what I was doing and the port I was told it was. So my dealing with hjr left a sour taste in my mouth and a unhappy costumer. Now I know I'm going to get pm's that I'm an idiot, don't know what I'm talking about, but this was my personal dealing with hjr. I also know of another member that had exactly the same issues as me. What exactly was the issue with your domes? Was your compression low or just an excessive squish band? Quote Link to comment Share on other sites More sharing options...
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