Author Topic: Low compression, whats next? (Read 17161 times)

countryboy9799 · « **Reply #15 on:** February 28, 2015, 08:29:20 PM »

Well I found the problem of where the play was in the crank on the left side.

The bearing on the left side for the inside diamater is somewhere around 1.075 and 1.085. The crank on that side is around 1.097 to 1.100 which the right side crank is about 1.100. Both bearings are tight in the case so did I dodge a bullet or do I need a new crank? I was hoping the play would be in the bearings themselves but there doesn't seem to be any although the left one does feel rough but the right side feels pretty good.

I never did find where that antifreeze got into the stator case. The only thing I can think of is when I took that drain plug out of the side of the block a few weeks ago drained some in through where the wires go through the stator case.

I measured the piston and cylinder the best I could using a calipers, I know it isn't the best thing to use but its what I have and that tested out at 2.600 which is about 66 MM. Does that mean my bore has never been bored out? That would be great. I plan on taking it somewhere to have it checked and bored if needed. The piston looked really good, no scoring or anything. Just some carbon on top.

countryboy9799 · « **Reply #16 on:** March 01, 2015, 12:04:07 PM »

Heres a bunch pics. You can see some wear on the crank where the bearing goes. Any hope for this?

The piston looks like a stock size, there would be a marking on it if it had been bored right?

countryboy9799 · « **Reply #17 on:** March 01, 2015, 12:05:14 PM »

In the last pic it looks like they stripped the threads for the drain plug and is that some form of liquid thread fix or did they weld it?

2ndmoto · « **Reply #18 on:** March 01, 2015, 01:56:53 PM »

Measure the shafts on the crank to see if they are worn or out of tolerance. Pretty sure the right side bearing is a slip fit, left should be an intereference fit. Rough bearings will absolulely give it end play.

Usually there are stamped markings on top of the piston. You can clean the carbon off to to verify.

Hard to see the drain hole, the picture is small on my tablet. The best is to have it kingserted or like. I have ran helicoil solutions on cases without issue, but that is not as good as some of the other insertable threads. Welding is also a solution, but not as insertable threads in my opinion. Welding the cases can be expensive, it will deform them (so they need to be flat plated or machined on the mating surfaces) and it will anneal the aluminum in that area making it a little bit weaker.

Best regards
-Jason

countryboy9799 · « **Reply #19 on:** March 01, 2015, 06:49:48 PM »

I cant find the tolerance in the Honda Service Manual I have. Anyone know what it is?

I have 1.100 and looking at a new bearing it specs out as 28MM which is 1.10236. I would think 2 to 4 thousandths of an inch might be a problem for a crank.

I wonder if there is some sort of loctite that I could use to put it together. I have known people that brazed/bronzed shafts that were in pretty bad shape and it worked. This is different though and I want to do it right also. Anyone have a new bearing they could measure the ID?

The threads are ok but it looks like it had been repaired at some point.

I couldn't find any markings so it must be a stock size. Thats one good thing at least!

Thanks

aztecgwynn · « **Reply #20 on:** March 02, 2015, 10:08:00 AM »

At this point you have too many things going against you! Start over and buy and replace all bearings and gaskets, have cylinder bored out with new piston kit. Replace old parts with new OEM Honda bearings and gaskets it will be expensive but you will be happier you used and spent on good parts. When all is done re do a pressure check on your motor. Also want you to know if engine leaks thru reeds, exhaust flange, lower cylinder base gasket, spark plug, crank seals, or leak down tester that is all normal. But you should never have to plug or hold transmission breather on leak down test. But f you are leaking from transmission breather or oil drain plug that is clear indication you will have to replace center case gasket!!
Good luck on your build!

fearlessfred · « **Reply #21 on:** March 02, 2015, 11:13:59 AM »

Quote from: aztecgwynn;50882

At this point you have too many things going against you! Start over and buy and replace all bearings and gaskets, have cylinder bored out with new piston kit. Replace old parts with new OEM Honda bearings and gaskets it will be expensive but you will be happier you used and spent on good parts. When all is done re do a pressure check on your motor. Also want you to know if engine leaks thru reeds, exhaust flange, lower cylinder base gasket, spark plug, crank seals, or leak down tester that is all normal. But you should never have to plug or hold transmission breather on leak down test. But f you are leaking from transmission breather or oil drain plug that is clear indication you will have to replace center case gasket!!
Good luck on your build!

Not clear indication that center gasket is leaking,more than likely an indication of right side crank seal leaking and using the breather to check for leak was good thinking and the first place I would go.I have never had a center gasket leak ,but have had plenty of right side crank seals leak

aztecgwynn · « **Reply #22 on:** March 02, 2015, 12:29:52 PM »

Reason I knew it was not seals leaking was I took engine oil bolt off and there I could hear air I was pumping in coming right out. I then with help figured it out and it was center case gasket. It was pinched and was not sealing properly, after gasket was replaced and new head gasket and bottom cylinder gasket was changed all necessary adjustments made she held pressure. That was the first and hopefully last engine I see with a bad center case gasket.
and let's hope that center case does not leak for anyone. It is a time consuming fix.

countryboy9799 · « **Reply #23 on:** March 02, 2015, 05:14:31 PM »

I plan on replacing all the bearings in the transmission and crank bearings along with the crank seals.

I am also going to a cyl. Boring shop to have it measured, it will most likely be bored to the next size.

My only real concern now is the crank, I need to know if the new bearings will be to loose on the crank. I think they will be so what's the next step? Get a hot rods crank or is there a way to salvage mine?

Thanks

Tbone07 · « **Reply #24 on:** March 02, 2015, 06:57:23 PM »

You have almost no way in telling how many hours are on that crank. If the crank is so worn that there is play between the bearing, then it's time for a new crank. The rod on an OEM crank can be rebuilt but not the surface I think you're referring to.

You're best bet would be to get a new crank. Spend the money and do the work now before the crank blows through your cases. It's worth the peace of mind

Skeans1 · « **Reply #25 on:** March 02, 2015, 07:22:14 PM »

They can build that surface back up with flame spraying but is it worth the money probably not with how cheap a hot rods crank is.

countryboy9799 · « **Reply #26 on:** March 03, 2015, 11:06:35 AM »

I can get this hot rod crank from amazon and with prime it would be here in 2 days. Is there anything better about the ones from ebay or BDT that run up to 100 dollars more?

http://www.amazon.com/Hot-Rods-4007-Crankshaft/dp/B000FT7E64/ref=sr_1_1?ie=UTF8&qid=1425396187&sr=8-1&keywords=hot+rod+crank+4007#productDetails

I was thinking I may be able to skip the bearing for the shift drum as that feels good and its not like that bearing really turns that much. I will defiantly replace the 4 bearings that those to shafts with the gears sit on. They feel rough and they also turn much faster. Does that sound right?

Tbone07 · « **Reply #27 on:** March 03, 2015, 02:46:59 PM »

Quote from: countryboy9799;50929

I can get this hot rod crank from amazon and with prime it would be here in 2 days. Is there anything better about the ones from ebay or BDT that run up to 100 dollars more?

http://www.amazon.com/Hot-Rods-4007-Crankshaft/dp/B000FT7E64/ref=sr_1_1?ie=UTF8&qid=1425396187&sr=8-1&keywords=hot+rod+crank+4007#productDetails

I was thinking I may be able to skip the bearing for the shift drum as that feels good and its not like that bearing really turns that much. I will defiantly replace the 4 bearings that those to shafts with the gears sit on. They feel rough and they also turn much faster. Does that sound right?

No there isn't anything better about the more expensive crankshaft.

I usually stick to Motosport or Rocky Mountain ATV/MC to purchase items like that. Ebay and Amazon can be iffy for certain products.

Definitely replace the 4 transmission shaft gears. Also look at replacing the 2 counter balancer bearings

countryboy9799 · « **Reply #28 on:** March 05, 2015, 09:55:43 AM »

I have ordered a Hot Rod Crank and have the cylinder at a place to be bored. Now all I need to do is order all the gaskets and bearings I need along with any tools if I need any. Just looking for thoughts on whether I need the tools for assembly or I have thought about taking it to the Honda shop. The Honda shop was very good to me the last time I was there, they sold me the flywheel tool for 20 bucks and removed it for me. I know I could have gotten the puller a little cheaper but it was nice to have them remove it since they had an impact wrench.

Just looking for tips and tricks to get it back together without that drive shaft dis/assembly tool.

Thanks

countryboy9799 · « **Reply #29 on:** March 05, 2015, 10:21:05 AM »

From what I have saw it looks like cheapcycleparts and hondapartsnation.com have the all the bearings and gaskets that I need at a cheaper price. I emailed cheapcycleparts to see if they were Honda parts and they never responded back to me. Today I called Honda parts nation and they said their bearings were all Authentic Honda parts so I should be good there. Let me know if there is a better place to order bearings.